Adding basic imputil documentation.

[python.git] / Modules / socketmodule.c

/* Socket module */

/*

This module provides an interface to Berkeley socket IPC.

Limitations:

- Only AF_INET, AF_INET6 and AF_UNIX address families are supported in a
  portable manner, though AF_PACKET and AF_NETLINK are supported under Linux.
- No read/write operations (use sendall/recv or makefile instead).
- Additional restrictions apply on some non-Unix platforms (compensated
  for by socket.py).

Module interface:

- socket.error: exception raised for socket specific errors
- socket.gaierror: exception raised for getaddrinfo/getnameinfo errors,
        a subclass of socket.error
- socket.herror: exception raised for gethostby* errors,
        a subclass of socket.error
- socket.fromfd(fd, family, type[, proto]) --> new socket object (created
        from an existing file descriptor)
- socket.gethostbyname(hostname) --> host IP address (string: 'dd.dd.dd.dd')
- socket.gethostbyaddr(IP address) --> (hostname, [alias, ...], [IP addr, ...])
- socket.gethostname() --> host name (string: 'spam' or 'spam.domain.com')
- socket.getprotobyname(protocolname) --> protocol number
- socket.getservbyname(servicename[, protocolname]) --> port number
- socket.getservbyport(portnumber[, protocolname]) --> service name
- socket.socket([family[, type [, proto]]]) --> new socket object
- socket.socketpair([family[, type [, proto]]]) --> (socket, socket)
- socket.ntohs(16 bit value) --> new int object
- socket.ntohl(32 bit value) --> new int object
- socket.htons(16 bit value) --> new int object
- socket.htonl(32 bit value) --> new int object
- socket.getaddrinfo(host, port [, family, socktype, proto, flags])
        --> List of (family, socktype, proto, canonname, sockaddr)
- socket.getnameinfo(sockaddr, flags) --> (host, port)
- socket.AF_INET, socket.SOCK_STREAM, etc.: constants from <socket.h>
- socket.has_ipv6: boolean value indicating if IPv6 is supported
- socket.inet_aton(IP address) -> 32-bit packed IP representation
- socket.inet_ntoa(packed IP) -> IP address string
- socket.getdefaulttimeout() -> None | float
- socket.setdefaulttimeout(None | float)
- an Internet socket address is a pair (hostname, port)
  where hostname can be anything recognized by gethostbyname()
  (including the dd.dd.dd.dd notation) and port is in host byte order
- where a hostname is returned, the dd.dd.dd.dd notation is used
- a UNIX domain socket address is a string specifying the pathname
- an AF_PACKET socket address is a tuple containing a string
  specifying the ethernet interface and an integer specifying
  the Ethernet protocol number to be received. For example:
  ("eth0",0x1234).  Optional 3rd,4th,5th elements in the tuple
  specify packet-type and ha-type/addr.

Local naming conventions:

- names starting with sock_ are socket object methods
- names starting with socket_ are module-level functions
- names starting with PySocket are exported through socketmodule.h

*/

#ifdef __APPLE__
  /*
   * inet_aton is not available on OSX 10.3, yet we want to use a binary
   * that was build on 10.4 or later to work on that release, weak linking
   * comes to the rescue.
   */
# pragma weak inet_aton
#endif

#include "Python.h"
#include "structmember.h"

#undef MAX
#define MAX(x, y) ((x) < (y) ? (y) : (x))

/* Socket object documentation */
PyDoc_STRVAR(sock_doc,
"socket([family[, type[, proto]]]) -> socket object\n\
\n\
Open a socket of the given type.  The family argument specifies the\n\
address family; it defaults to AF_INET.  The type argument specifies\n\
whether this is a stream (SOCK_STREAM, this is the default)\n\
or datagram (SOCK_DGRAM) socket.  The protocol argument defaults to 0,\n\
specifying the default protocol.  Keyword arguments are accepted.\n\
\n\
A socket object represents one endpoint of a network connection.\n\
\n\
Methods of socket objects (keyword arguments not allowed):\n\
\n\
accept() -- accept a connection, returning new socket and client address\n\
bind(addr) -- bind the socket to a local address\n\
close() -- close the socket\n\
connect(addr) -- connect the socket to a remote address\n\
connect_ex(addr) -- connect, return an error code instead of an exception\n\
dup() -- return a new socket object identical to the current one [*]\n\
fileno() -- return underlying file descriptor\n\
getpeername() -- return remote address [*]\n\
getsockname() -- return local address\n\
getsockopt(level, optname[, buflen]) -- get socket options\n\
gettimeout() -- return timeout or None\n\
listen(n) -- start listening for incoming connections\n\
makefile([mode, [bufsize]]) -- return a file object for the socket [*]\n\
recv(buflen[, flags]) -- receive data\n\
recv_into(buffer[, nbytes[, flags]]) -- receive data (into a buffer)\n\
recvfrom(buflen[, flags]) -- receive data and sender\'s address\n\
recvfrom_into(buffer[, nbytes, [, flags])\n\
  -- receive data and sender\'s address (into a buffer)\n\
sendall(data[, flags]) -- send all data\n\
send(data[, flags]) -- send data, may not send all of it\n\
sendto(data[, flags], addr) -- send data to a given address\n\
setblocking(0 | 1) -- set or clear the blocking I/O flag\n\
setsockopt(level, optname, value) -- set socket options\n\
settimeout(None | float) -- set or clear the timeout\n\
shutdown(how) -- shut down traffic in one or both directions\n\
\n\
 [*] not available on all platforms!");

/* XXX This is a terrible mess of platform-dependent preprocessor hacks.
   I hope some day someone can clean this up please... */

/* Hacks for gethostbyname_r().  On some non-Linux platforms, the configure
   script doesn't get this right, so we hardcode some platform checks below.
   On the other hand, not all Linux versions agree, so there the settings
   computed by the configure script are needed! */

#ifndef linux
# undef HAVE_GETHOSTBYNAME_R_3_ARG
# undef HAVE_GETHOSTBYNAME_R_5_ARG
# undef HAVE_GETHOSTBYNAME_R_6_ARG
#endif

#ifndef WITH_THREAD
# undef HAVE_GETHOSTBYNAME_R
#endif

#ifdef HAVE_GETHOSTBYNAME_R
# if defined(_AIX) || defined(__osf__)
#  define HAVE_GETHOSTBYNAME_R_3_ARG
# elif defined(__sun) || defined(__sgi)
#  define HAVE_GETHOSTBYNAME_R_5_ARG
# elif defined(linux)
/* Rely on the configure script */
# else
#  undef HAVE_GETHOSTBYNAME_R
# endif
#endif

#if !defined(HAVE_GETHOSTBYNAME_R) && defined(WITH_THREAD) && \
    !defined(MS_WINDOWS)
# define USE_GETHOSTBYNAME_LOCK
#endif

/* To use __FreeBSD_version */
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
/* On systems on which getaddrinfo() is believed to not be thread-safe,
   (this includes the getaddrinfo emulation) protect access with a lock. */
#if defined(WITH_THREAD) && (defined(__APPLE__) || \
    (defined(__FreeBSD__) && __FreeBSD_version+0 < 503000) || \
    defined(__OpenBSD__) || defined(__NetBSD__) || \
    defined(__VMS) || !defined(HAVE_GETADDRINFO))
#define USE_GETADDRINFO_LOCK
#endif

#ifdef USE_GETADDRINFO_LOCK
#define ACQUIRE_GETADDRINFO_LOCK PyThread_acquire_lock(netdb_lock, 1);
#define RELEASE_GETADDRINFO_LOCK PyThread_release_lock(netdb_lock);
#else
#define ACQUIRE_GETADDRINFO_LOCK
#define RELEASE_GETADDRINFO_LOCK
#endif

#if defined(USE_GETHOSTBYNAME_LOCK) || defined(USE_GETADDRINFO_LOCK)
# include "pythread.h"
#endif

#if defined(PYCC_VACPP)
# include <types.h>
# include <io.h>
# include <sys/ioctl.h>
# include <utils.h>
# include <ctype.h>
#endif

#if defined(__VMS)
#  include <ioctl.h>
#endif

#if defined(PYOS_OS2)
# define  INCL_DOS
# define  INCL_DOSERRORS
# define  INCL_NOPMAPI
# include <os2.h>
#endif

#if defined(__sgi) && _COMPILER_VERSION>700 && !_SGIAPI
/* make sure that the reentrant (gethostbyaddr_r etc)
   functions are declared correctly if compiling with
   MIPSPro 7.x in ANSI C mode (default) */

/* XXX Using _SGIAPI is the wrong thing,
   but I don't know what the right thing is. */
#undef _SGIAPI /* to avoid warning */
#define _SGIAPI 1

#undef _XOPEN_SOURCE
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#ifdef _SS_ALIGNSIZE
#define HAVE_GETADDRINFO 1
#define HAVE_GETNAMEINFO 1
#endif

#define HAVE_INET_PTON
#include <netdb.h>
#endif

/* Irix 6.5 fails to define this variable at all. This is needed
   for both GCC and SGI's compiler. I'd say that the SGI headers
   are just busted. Same thing for Solaris. */
#if (defined(__sgi) || defined(sun)) && !defined(INET_ADDRSTRLEN)
#define INET_ADDRSTRLEN 16
#endif

/* Generic includes */
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif

/* Generic socket object definitions and includes */
#define PySocket_BUILDING_SOCKET
#include "socketmodule.h"

/* Addressing includes */

#ifndef MS_WINDOWS

/* Non-MS WINDOWS includes */
# include <netdb.h>

/* Headers needed for inet_ntoa() and inet_addr() */
# ifdef __BEOS__
#  include <net/netdb.h>
# elif defined(PYOS_OS2) && defined(PYCC_VACPP)
#  include <netdb.h>
typedef size_t socklen_t;
# else
#   include <arpa/inet.h>
# endif

# ifndef RISCOS
#  include <fcntl.h>
# else
#  include <sys/ioctl.h>
#  include <socklib.h>
#  define NO_DUP
int h_errno; /* not used */
#  define INET_ADDRSTRLEN 16
# endif

#else

/* MS_WINDOWS includes */
# ifdef HAVE_FCNTL_H
#  include <fcntl.h>
# endif

#endif

#include <stddef.h>

#ifndef offsetof
# define offsetof(type, member) ((size_t)(&((type *)0)->member))
#endif

#ifndef O_NONBLOCK
# define O_NONBLOCK O_NDELAY
#endif

/* include Python's addrinfo.h unless it causes trouble */
#if defined(__sgi) && _COMPILER_VERSION>700 && defined(_SS_ALIGNSIZE)
  /* Do not include addinfo.h on some newer IRIX versions.
   * _SS_ALIGNSIZE is defined in sys/socket.h by 6.5.21,
   * for example, but not by 6.5.10.
   */
#elif defined(_MSC_VER) && _MSC_VER>1201
  /* Do not include addrinfo.h for MSVC7 or greater. 'addrinfo' and
   * EAI_* constants are defined in (the already included) ws2tcpip.h.
   */
#else
#  include "addrinfo.h"
#endif

#ifndef HAVE_INET_PTON
int inet_pton(int af, const char *src, void *dst);
const char *inet_ntop(int af, const void *src, char *dst, socklen_t size);
#endif

#ifdef __APPLE__
/* On OS X, getaddrinfo returns no error indication of lookup
   failure, so we must use the emulation instead of the libinfo
   implementation. Unfortunately, performing an autoconf test
   for this bug would require DNS access for the machine performing
   the configuration, which is not acceptable. Therefore, we
   determine the bug just by checking for __APPLE__. If this bug
   gets ever fixed, perhaps checking for sys/version.h would be
   appropriate, which is 10/0 on the system with the bug. */
#ifndef HAVE_GETNAMEINFO
/* This bug seems to be fixed in Jaguar. Ths easiest way I could
   Find to check for Jaguar is that it has getnameinfo(), which
   older releases don't have */
#undef HAVE_GETADDRINFO
#endif

#ifdef HAVE_INET_ATON
#define USE_INET_ATON_WEAKLINK
#endif

#endif

/* I know this is a bad practice, but it is the easiest... */
#if !defined(HAVE_GETADDRINFO)
/* avoid clashes with the C library definition of the symbol. */
#define getaddrinfo fake_getaddrinfo
#define gai_strerror fake_gai_strerror
#define freeaddrinfo fake_freeaddrinfo
#include "getaddrinfo.c"
#endif
#if !defined(HAVE_GETNAMEINFO)
#define getnameinfo fake_getnameinfo
#include "getnameinfo.c"
#endif

#if defined(MS_WINDOWS) || defined(__BEOS__)
/* BeOS suffers from the same socket dichotomy as Win32... - [cjh] */
/* seem to be a few differences in the API */
#define SOCKETCLOSE closesocket
#define NO_DUP /* Actually it exists on NT 3.5, but what the heck... */
#endif

#ifdef MS_WIN32
#define EAFNOSUPPORT WSAEAFNOSUPPORT
#define snprintf _snprintf
#endif

#if defined(PYOS_OS2) && !defined(PYCC_GCC)
#define SOCKETCLOSE soclose
#define NO_DUP /* Sockets are Not Actual File Handles under OS/2 */
#endif

#ifndef SOCKETCLOSE
#define SOCKETCLOSE close
#endif

#if defined(HAVE_BLUETOOTH_H) || defined(HAVE_BLUETOOTH_BLUETOOTH_H)
#define USE_BLUETOOTH 1
#if defined(__FreeBSD__)
#define BTPROTO_L2CAP BLUETOOTH_PROTO_L2CAP
#define BTPROTO_RFCOMM BLUETOOTH_PROTO_RFCOMM
#define BTPROTO_HCI BLUETOOTH_PROTO_HCI
#define SOL_HCI SOL_HCI_RAW
#define HCI_FILTER SO_HCI_RAW_FILTER
#define sockaddr_l2 sockaddr_l2cap
#define sockaddr_rc sockaddr_rfcomm
#define hci_dev hci_node
#define _BT_L2_MEMB(sa, memb) ((sa)->l2cap_##memb)
#define _BT_RC_MEMB(sa, memb) ((sa)->rfcomm_##memb)
#define _BT_HCI_MEMB(sa, memb) ((sa)->hci_##memb)
#elif defined(__NetBSD__)
#define sockaddr_l2 sockaddr_bt
#define sockaddr_rc sockaddr_bt
#define sockaddr_hci sockaddr_bt
#define sockaddr_sco sockaddr_bt
#define _BT_L2_MEMB(sa, memb) ((sa)->bt_##memb)
#define _BT_RC_MEMB(sa, memb) ((sa)->bt_##memb)
#define _BT_HCI_MEMB(sa, memb) ((sa)->bt_##memb)
#define _BT_SCO_MEMB(sa, memb) ((sa)->bt_##memb)
#else
#define _BT_L2_MEMB(sa, memb) ((sa)->l2_##memb)
#define _BT_RC_MEMB(sa, memb) ((sa)->rc_##memb)
#define _BT_HCI_MEMB(sa, memb) ((sa)->hci_##memb)
#define _BT_SCO_MEMB(sa, memb) ((sa)->sco_##memb)
#endif
#endif

#ifdef __VMS
/* TCP/IP Services for VMS uses a maximum send/recv buffer length */
#define SEGMENT_SIZE (32 * 1024 -1)
#endif

#define SAS2SA(x)       ((struct sockaddr *)(x))

/*
 * Constants for getnameinfo()
 */
#if !defined(NI_MAXHOST)
#define NI_MAXHOST 1025
#endif
#if !defined(NI_MAXSERV)
#define NI_MAXSERV 32
#endif

/* XXX There's a problem here: *static* functions are not supposed to have
   a Py prefix (or use CapitalizedWords).  Later... */

/* Global variable holding the exception type for errors detected
   by this module (but not argument type or memory errors, etc.). */
static PyObject *socket_error;
static PyObject *socket_herror;
static PyObject *socket_gaierror;
static PyObject *socket_timeout;

#ifdef RISCOS
/* Global variable which is !=0 if Python is running in a RISC OS taskwindow */
static int taskwindow;
#endif

/* A forward reference to the socket type object.
   The sock_type variable contains pointers to various functions,
   some of which call new_sockobject(), which uses sock_type, so
   there has to be a circular reference. */
static PyTypeObject sock_type;

#if defined(HAVE_POLL_H)
#include <poll.h>
#elif defined(HAVE_SYS_POLL_H)
#include <sys/poll.h>
#endif

#ifdef Py_SOCKET_FD_CAN_BE_GE_FD_SETSIZE
/* Platform can select file descriptors beyond FD_SETSIZE */
#define IS_SELECTABLE(s) 1
#elif defined(HAVE_POLL)
/* Instead of select(), we'll use poll() since poll() works on any fd. */
#define IS_SELECTABLE(s) 1
/* Can we call select() with this socket without a buffer overrun? */
#else
/* POSIX says selecting file descriptors beyond FD_SETSIZE
   has undefined behaviour.  If there's no timeout left, we don't have to
   call select, so it's a safe, little white lie. */
#define IS_SELECTABLE(s) ((s)->sock_fd < FD_SETSIZE || s->sock_timeout <= 0.0)
#endif

static PyObject*
select_error(void)
{
        PyErr_SetString(socket_error, "unable to select on socket");
        return NULL;
}

/* Convenience function to raise an error according to errno
   and return a NULL pointer from a function. */

static PyObject *
set_error(void)
{
#ifdef MS_WINDOWS
        int err_no = WSAGetLastError();
        static struct {
                int no;
                const char *msg;
        } *msgp, msgs[] = {
                {WSAEINTR, "Interrupted system call"},
                {WSAEBADF, "Bad file descriptor"},
                {WSAEACCES, "Permission denied"},
                {WSAEFAULT, "Bad address"},
                {WSAEINVAL, "Invalid argument"},
                {WSAEMFILE, "Too many open files"},
                {WSAEWOULDBLOCK,
                  "The socket operation could not complete "
                  "without blocking"},
                {WSAEINPROGRESS, "Operation now in progress"},
                {WSAEALREADY, "Operation already in progress"},
                {WSAENOTSOCK, "Socket operation on non-socket"},
                {WSAEDESTADDRREQ, "Destination address required"},
                {WSAEMSGSIZE, "Message too long"},
                {WSAEPROTOTYPE, "Protocol wrong type for socket"},
                {WSAENOPROTOOPT, "Protocol not available"},
                {WSAEPROTONOSUPPORT, "Protocol not supported"},
                {WSAESOCKTNOSUPPORT, "Socket type not supported"},
                {WSAEOPNOTSUPP, "Operation not supported"},
                {WSAEPFNOSUPPORT, "Protocol family not supported"},
                {WSAEAFNOSUPPORT, "Address family not supported"},
                {WSAEADDRINUSE, "Address already in use"},
                {WSAEADDRNOTAVAIL, "Can't assign requested address"},
                {WSAENETDOWN, "Network is down"},
                {WSAENETUNREACH, "Network is unreachable"},
                {WSAENETRESET, "Network dropped connection on reset"},
                {WSAECONNABORTED, "Software caused connection abort"},
                {WSAECONNRESET, "Connection reset by peer"},
                {WSAENOBUFS, "No buffer space available"},
                {WSAEISCONN, "Socket is already connected"},
                {WSAENOTCONN, "Socket is not connected"},
                {WSAESHUTDOWN, "Can't send after socket shutdown"},
                {WSAETOOMANYREFS, "Too many references: can't splice"},
                {WSAETIMEDOUT, "Operation timed out"},
                {WSAECONNREFUSED, "Connection refused"},
                {WSAELOOP, "Too many levels of symbolic links"},
                {WSAENAMETOOLONG, "File name too long"},
                {WSAEHOSTDOWN, "Host is down"},
                {WSAEHOSTUNREACH, "No route to host"},
                {WSAENOTEMPTY, "Directory not empty"},
                {WSAEPROCLIM, "Too many processes"},
                {WSAEUSERS, "Too many users"},
                {WSAEDQUOT, "Disc quota exceeded"},
                {WSAESTALE, "Stale NFS file handle"},
                {WSAEREMOTE, "Too many levels of remote in path"},
                {WSASYSNOTREADY, "Network subsystem is unvailable"},
                {WSAVERNOTSUPPORTED, "WinSock version is not supported"},
                {WSANOTINITIALISED,
                  "Successful WSAStartup() not yet performed"},
                {WSAEDISCON, "Graceful shutdown in progress"},
                /* Resolver errors */
                {WSAHOST_NOT_FOUND, "No such host is known"},
                {WSATRY_AGAIN, "Host not found, or server failed"},
                {WSANO_RECOVERY, "Unexpected server error encountered"},
                {WSANO_DATA, "Valid name without requested data"},
                {WSANO_ADDRESS, "No address, look for MX record"},
                {0, NULL}
        };
        if (err_no) {
                PyObject *v;
                const char *msg = "winsock error";

                for (msgp = msgs; msgp->msg; msgp++) {
                        if (err_no == msgp->no) {
                                msg = msgp->msg;
                                break;
                        }
                }

                v = Py_BuildValue("(is)", err_no, msg);
                if (v != NULL) {
                        PyErr_SetObject(socket_error, v);
                        Py_DECREF(v);
                }
                return NULL;
        }
        else
#endif

#if defined(PYOS_OS2) && !defined(PYCC_GCC)
        if (sock_errno() != NO_ERROR) {
                APIRET rc;
                ULONG  msglen;
                char outbuf[100];
                int myerrorcode = sock_errno();

                /* Retrieve socket-related error message from MPTN.MSG file */
                rc = DosGetMessage(NULL, 0, outbuf, sizeof(outbuf),
                                   myerrorcode - SOCBASEERR + 26,
                                   "mptn.msg",
                                   &msglen);
                if (rc == NO_ERROR) {
                        PyObject *v;

                        /* OS/2 doesn't guarantee a terminator */
                        outbuf[msglen] = '\0';
                        if (strlen(outbuf) > 0) {
                                /* If non-empty msg, trim CRLF */
                                char *lastc = &outbuf[ strlen(outbuf)-1 ];
                                while (lastc > outbuf &&
                                       isspace(Py_CHARMASK(*lastc))) {
                                        /* Trim trailing whitespace (CRLF) */
                                        *lastc-- = '\0';
                                }
                        }
                        v = Py_BuildValue("(is)", myerrorcode, outbuf);
                        if (v != NULL) {
                                PyErr_SetObject(socket_error, v);
                                Py_DECREF(v);
                        }
                        return NULL;
                }
        }
#endif

#if defined(RISCOS)
        if (_inet_error.errnum != NULL) {
                PyObject *v;
                v = Py_BuildValue("(is)", errno, _inet_err());
                if (v != NULL) {
                        PyErr_SetObject(socket_error, v);
                        Py_DECREF(v);
                }
                return NULL;
        }
#endif

        return PyErr_SetFromErrno(socket_error);
}


static PyObject *
set_herror(int h_error)
{
        PyObject *v;

#ifdef HAVE_HSTRERROR
        v = Py_BuildValue("(is)", h_error, (char *)hstrerror(h_error));
#else
        v = Py_BuildValue("(is)", h_error, "host not found");
#endif
        if (v != NULL) {
                PyErr_SetObject(socket_herror, v);
                Py_DECREF(v);
        }

        return NULL;
}


static PyObject *
set_gaierror(int error)
{
        PyObject *v;

#ifdef EAI_SYSTEM
        /* EAI_SYSTEM is not available on Windows XP. */
        if (error == EAI_SYSTEM)
                return set_error();
#endif

#ifdef HAVE_GAI_STRERROR
        v = Py_BuildValue("(is)", error, gai_strerror(error));
#else
        v = Py_BuildValue("(is)", error, "getaddrinfo failed");
#endif
        if (v != NULL) {
                PyErr_SetObject(socket_gaierror, v);
                Py_DECREF(v);
        }

        return NULL;
}

#ifdef __VMS
/* Function to send in segments */
static int
sendsegmented(int sock_fd, char *buf, int len, int flags)
{
        int n = 0;
        int remaining = len;

        while (remaining > 0) {
                unsigned int segment;

                segment = (remaining >= SEGMENT_SIZE ? SEGMENT_SIZE : remaining);
                n = send(sock_fd, buf, segment, flags);
                if (n < 0) {
                        return n;
                }
                remaining -= segment;
                buf += segment;
        } /* end while */

        return len;
}
#endif

/* Function to perform the setting of socket blocking mode
   internally. block = (1 | 0). */
static int
internal_setblocking(PySocketSockObject *s, int block)
{
#ifndef RISCOS
#ifndef MS_WINDOWS
        int delay_flag;
#endif
#endif

        Py_BEGIN_ALLOW_THREADS
#ifdef __BEOS__
        block = !block;
        setsockopt(s->sock_fd, SOL_SOCKET, SO_NONBLOCK,
                   (void *)(&block), sizeof(int));
#else
#ifndef RISCOS
#ifndef MS_WINDOWS
#if defined(PYOS_OS2) && !defined(PYCC_GCC)
        block = !block;
        ioctl(s->sock_fd, FIONBIO, (caddr_t)&block, sizeof(block));
#elif defined(__VMS)
        block = !block;
        ioctl(s->sock_fd, FIONBIO, (unsigned int *)&block);
#else  /* !PYOS_OS2 && !__VMS */
        delay_flag = fcntl(s->sock_fd, F_GETFL, 0);
        if (block)
                delay_flag &= (~O_NONBLOCK);
        else
                delay_flag |= O_NONBLOCK;
        fcntl(s->sock_fd, F_SETFL, delay_flag);
#endif /* !PYOS_OS2 */
#else /* MS_WINDOWS */
        block = !block;
        ioctlsocket(s->sock_fd, FIONBIO, (u_long*)&block);
#endif /* MS_WINDOWS */
#else /* RISCOS */
        block = !block;
        socketioctl(s->sock_fd, FIONBIO, (u_long*)&block);
#endif /* RISCOS */
#endif /* __BEOS__ */
        Py_END_ALLOW_THREADS

        /* Since these don't return anything */
        return 1;
}

/* Do a select()/poll() on the socket, if necessary (sock_timeout > 0).
   The argument writing indicates the direction.
   This does not raise an exception; we'll let our caller do that
   after they've reacquired the interpreter lock.
   Returns 1 on timeout, -1 on error, 0 otherwise. */
static int
internal_select(PySocketSockObject *s, int writing)
{
        int n;

        /* Nothing to do unless we're in timeout mode (not non-blocking) */
        if (s->sock_timeout <= 0.0)
                return 0;

        /* Guard against closed socket */
        if (s->sock_fd < 0)
                return 0;

        /* Prefer poll, if available, since you can poll() any fd
         * which can't be done with select(). */
#ifdef HAVE_POLL
        {
                struct pollfd pollfd;
                int timeout;

                pollfd.fd = s->sock_fd;
                pollfd.events = writing ? POLLOUT : POLLIN;

                /* s->sock_timeout is in seconds, timeout in ms */
                timeout = (int)(s->sock_timeout * 1000 + 0.5); 
                n = poll(&pollfd, 1, timeout);
        }
#else
        {
                /* Construct the arguments to select */
                fd_set fds;
                struct timeval tv;
                tv.tv_sec = (int)s->sock_timeout;
                tv.tv_usec = (int)((s->sock_timeout - tv.tv_sec) * 1e6);
                FD_ZERO(&fds);
                FD_SET(s->sock_fd, &fds);

                /* See if the socket is ready */
                if (writing)
                        n = select(s->sock_fd+1, NULL, &fds, NULL, &tv);
                else
                        n = select(s->sock_fd+1, &fds, NULL, NULL, &tv);
        }
#endif
        
        if (n < 0)
                return -1;
        if (n == 0)
                return 1;
        return 0;
}

/* Initialize a new socket object. */

static double defaulttimeout = -1.0; /* Default timeout for new sockets */

PyMODINIT_FUNC
init_sockobject(PySocketSockObject *s,
                SOCKET_T fd, int family, int type, int proto)
{
#ifdef RISCOS
        int block = 1;
#endif
        s->sock_fd = fd;
        s->sock_family = family;
        s->sock_type = type;
        s->sock_proto = proto;
        s->sock_timeout = defaulttimeout;

        s->errorhandler = &set_error;

        if (defaulttimeout >= 0.0)
                internal_setblocking(s, 0);

#ifdef RISCOS
        if (taskwindow)
                socketioctl(s->sock_fd, 0x80046679, (u_long*)&block);
#endif
}


/* Create a new socket object.
   This just creates the object and initializes it.
   If the creation fails, return NULL and set an exception (implicit
   in NEWOBJ()). */

static PySocketSockObject *
new_sockobject(SOCKET_T fd, int family, int type, int proto)
{
        PySocketSockObject *s;
        s = (PySocketSockObject *)
                PyType_GenericNew(&sock_type, NULL, NULL);
        if (s != NULL)
                init_sockobject(s, fd, family, type, proto);
        return s;
}


/* Lock to allow python interpreter to continue, but only allow one
   thread to be in gethostbyname or getaddrinfo */
#if defined(USE_GETHOSTBYNAME_LOCK) || defined(USE_GETADDRINFO_LOCK)
PyThread_type_lock netdb_lock;
#endif


/* Convert a string specifying a host name or one of a few symbolic
   names to a numeric IP address.  This usually calls gethostbyname()
   to do the work; the names "" and "<broadcast>" are special.
   Return the length (IPv4 should be 4 bytes), or negative if
   an error occurred; then an exception is raised. */

static int
setipaddr(char *name, struct sockaddr *addr_ret, size_t addr_ret_size, int af)
{
        struct addrinfo hints, *res;
        int error;
        int d1, d2, d3, d4;
        char ch;

        memset((void *) addr_ret, '\0', sizeof(*addr_ret));
        if (name[0] == '\0') {
                int siz;
                memset(&hints, 0, sizeof(hints));
                hints.ai_family = af;
                hints.ai_socktype = SOCK_DGRAM; /*dummy*/
                hints.ai_flags = AI_PASSIVE;
                Py_BEGIN_ALLOW_THREADS
                ACQUIRE_GETADDRINFO_LOCK
                error = getaddrinfo(NULL, "0", &hints, &res);
                Py_END_ALLOW_THREADS
                /* We assume that those thread-unsafe getaddrinfo() versions
                   *are* safe regarding their return value, ie. that a
                   subsequent call to getaddrinfo() does not destroy the
                   outcome of the first call. */
                RELEASE_GETADDRINFO_LOCK
                if (error) {
                        set_gaierror(error);
                        return -1;
                }
                switch (res->ai_family) {
                case AF_INET:
                        siz = 4;
                        break;
#ifdef ENABLE_IPV6
                case AF_INET6:
                        siz = 16;
                        break;
#endif
                default:
                        freeaddrinfo(res);
                        PyErr_SetString(socket_error,
                                "unsupported address family");
                        return -1;
                }
                if (res->ai_next) {
                        freeaddrinfo(res);
                        PyErr_SetString(socket_error,
                                "wildcard resolved to multiple address");
                        return -1;
                }
                if (res->ai_addrlen < addr_ret_size)
                        addr_ret_size = res->ai_addrlen;
                memcpy(addr_ret, res->ai_addr, addr_ret_size);
                freeaddrinfo(res);
                return siz;
        }
        if (name[0] == '<' && strcmp(name, "<broadcast>") == 0) {
                struct sockaddr_in *sin;
                if (af != AF_INET && af != AF_UNSPEC) {
                        PyErr_SetString(socket_error,
                                "address family mismatched");
                        return -1;
                }
                sin = (struct sockaddr_in *)addr_ret;
                memset((void *) sin, '\0', sizeof(*sin));
                sin->sin_family = AF_INET;
#ifdef HAVE_SOCKADDR_SA_LEN
                sin->sin_len = sizeof(*sin);
#endif
                sin->sin_addr.s_addr = INADDR_BROADCAST;
                return sizeof(sin->sin_addr);
        }
        if (sscanf(name, "%d.%d.%d.%d%c", &d1, &d2, &d3, &d4, &ch) == 4 &&
            0 <= d1 && d1 <= 255 && 0 <= d2 && d2 <= 255 &&
            0 <= d3 && d3 <= 255 && 0 <= d4 && d4 <= 255) {
                struct sockaddr_in *sin;
                sin = (struct sockaddr_in *)addr_ret;
                sin->sin_addr.s_addr = htonl(
                        ((long) d1 << 24) | ((long) d2 << 16) |
                        ((long) d3 << 8) | ((long) d4 << 0));
                sin->sin_family = AF_INET;
#ifdef HAVE_SOCKADDR_SA_LEN
                sin->sin_len = sizeof(*sin);
#endif
                return 4;
        }
        memset(&hints, 0, sizeof(hints));
        hints.ai_family = af;
        Py_BEGIN_ALLOW_THREADS
        ACQUIRE_GETADDRINFO_LOCK
        error = getaddrinfo(name, NULL, &hints, &res);
#if defined(__digital__) && defined(__unix__)
        if (error == EAI_NONAME && af == AF_UNSPEC) {
                /* On Tru64 V5.1, numeric-to-addr conversion fails
                   if no address family is given. Assume IPv4 for now.*/
                hints.ai_family = AF_INET;
                error = getaddrinfo(name, NULL, &hints, &res);
        }
#endif
        Py_END_ALLOW_THREADS
        RELEASE_GETADDRINFO_LOCK  /* see comment in setipaddr() */
        if (error) {
                set_gaierror(error);
                return -1;
        }
        if (res->ai_addrlen < addr_ret_size)
                addr_ret_size = res->ai_addrlen;
        memcpy((char *) addr_ret, res->ai_addr, addr_ret_size);
        freeaddrinfo(res);
        switch (addr_ret->sa_family) {
        case AF_INET:
                return 4;
#ifdef ENABLE_IPV6
        case AF_INET6:
                return 16;
#endif
        default:
                PyErr_SetString(socket_error, "unknown address family");
                return -1;
        }
}


/* Create a string object representing an IP address.
   This is always a string of the form 'dd.dd.dd.dd' (with variable
   size numbers). */

static PyObject *
makeipaddr(struct sockaddr *addr, int addrlen)
{
        char buf[NI_MAXHOST];
        int error;

        error = getnameinfo(addr, addrlen, buf, sizeof(buf), NULL, 0,
                NI_NUMERICHOST);
        if (error) {
                set_gaierror(error);
                return NULL;
        }
        return PyString_FromString(buf);
}


#ifdef USE_BLUETOOTH
/* Convert a string representation of a Bluetooth address into a numeric
   address.  Returns the length (6), or raises an exception and returns -1 if
   an error occurred. */

static int
setbdaddr(char *name, bdaddr_t *bdaddr)
{
        unsigned int b0, b1, b2, b3, b4, b5;
        char ch;
        int n;

        n = sscanf(name, "%X:%X:%X:%X:%X:%X%c",
                   &b5, &b4, &b3, &b2, &b1, &b0, &ch);
        if (n == 6 && (b0 | b1 | b2 | b3 | b4 | b5) < 256) {
                bdaddr->b[0] = b0;
                bdaddr->b[1] = b1;
                bdaddr->b[2] = b2;
                bdaddr->b[3] = b3;
                bdaddr->b[4] = b4;
                bdaddr->b[5] = b5;
                return 6;
        } else {
                PyErr_SetString(socket_error, "bad bluetooth address");
                return -1;
        }
}

/* Create a string representation of the Bluetooth address.  This is always a
   string of the form 'XX:XX:XX:XX:XX:XX' where XX is a two digit hexadecimal
   value (zero padded if necessary). */

static PyObject *
makebdaddr(bdaddr_t *bdaddr)
{
        char buf[(6 * 2) + 5 + 1];

        sprintf(buf, "%02X:%02X:%02X:%02X:%02X:%02X",
                bdaddr->b[5], bdaddr->b[4], bdaddr->b[3],
                bdaddr->b[2], bdaddr->b[1], bdaddr->b[0]);
        return PyString_FromString(buf);
}
#endif


/* Create an object representing the given socket address,
   suitable for passing it back to bind(), connect() etc.
   The family field of the sockaddr structure is inspected
   to determine what kind of address it really is. */

/*ARGSUSED*/
static PyObject *
makesockaddr(int sockfd, struct sockaddr *addr, int addrlen, int proto)
{
        if (addrlen == 0) {
                /* No address -- may be recvfrom() from known socket */
                Py_INCREF(Py_None);
                return Py_None;
        }

#ifdef __BEOS__
        /* XXX: BeOS version of accept() doesn't set family correctly */
        addr->sa_family = AF_INET;
#endif

        switch (addr->sa_family) {

        case AF_INET:
        {
                struct sockaddr_in *a;
                PyObject *addrobj = makeipaddr(addr, sizeof(*a));
                PyObject *ret = NULL;
                if (addrobj) {
                        a = (struct sockaddr_in *)addr;
                        ret = Py_BuildValue("Oi", addrobj, ntohs(a->sin_port));
                        Py_DECREF(addrobj);
                }
                return ret;
        }

#if defined(AF_UNIX)
        case AF_UNIX:
        {
                struct sockaddr_un *a = (struct sockaddr_un *) addr;
#ifdef linux
                if (a->sun_path[0] == 0) {  /* Linux abstract namespace */
                        addrlen -= (sizeof(*a) - sizeof(a->sun_path));
                        return PyString_FromStringAndSize(a->sun_path,
                                                          addrlen);
                }
                else
#endif /* linux */
                {
                        /* regular NULL-terminated string */
                        return PyString_FromString(a->sun_path);
                }
        }
#endif /* AF_UNIX */

#if defined(AF_NETLINK)
       case AF_NETLINK:
       {
               struct sockaddr_nl *a = (struct sockaddr_nl *) addr;
               return Py_BuildValue("II", a->nl_pid, a->nl_groups);
       }
#endif /* AF_NETLINK */

#ifdef ENABLE_IPV6
        case AF_INET6:
        {
                struct sockaddr_in6 *a;
                PyObject *addrobj = makeipaddr(addr, sizeof(*a));
                PyObject *ret = NULL;
                if (addrobj) {
                        a = (struct sockaddr_in6 *)addr;
                        ret = Py_BuildValue("Oiii",
                                            addrobj,
                                            ntohs(a->sin6_port),
                                            a->sin6_flowinfo,
                                            a->sin6_scope_id);
                        Py_DECREF(addrobj);
                }
                return ret;
        }
#endif

#ifdef USE_BLUETOOTH
        case AF_BLUETOOTH:
                switch (proto) {

                case BTPROTO_L2CAP:
                {
                        struct sockaddr_l2 *a = (struct sockaddr_l2 *) addr;
                        PyObject *addrobj = makebdaddr(&_BT_L2_MEMB(a, bdaddr));
                        PyObject *ret = NULL;
                        if (addrobj) {
                                ret = Py_BuildValue("Oi",
                                                    addrobj,
                                                    _BT_L2_MEMB(a, psm));
                                Py_DECREF(addrobj);
                        }
                        return ret;
                }

                case BTPROTO_RFCOMM:
                {
                        struct sockaddr_rc *a = (struct sockaddr_rc *) addr;
                        PyObject *addrobj = makebdaddr(&_BT_RC_MEMB(a, bdaddr));
                        PyObject *ret = NULL;
                        if (addrobj) {
                                ret = Py_BuildValue("Oi",
                                                    addrobj,
                                                    _BT_RC_MEMB(a, channel));
                                Py_DECREF(addrobj);
                        }
                        return ret;
                }

                case BTPROTO_HCI:
                {
                        struct sockaddr_hci *a = (struct sockaddr_hci *) addr;
                        PyObject *ret = NULL;
                        ret = Py_BuildValue("i", _BT_HCI_MEMB(a, dev));
                        return ret;
                }

#if !defined(__FreeBSD__)
                case BTPROTO_SCO:
                {
                        struct sockaddr_sco *a = (struct sockaddr_sco *) addr;
                        return makebdaddr(&_BT_SCO_MEMB(a, bdaddr));
                }
#endif

                }
#endif

#ifdef HAVE_NETPACKET_PACKET_H
        case AF_PACKET:
        {
                struct sockaddr_ll *a = (struct sockaddr_ll *)addr;
                char *ifname = "";
                struct ifreq ifr;
                /* need to look up interface name give index */
                if (a->sll_ifindex) {
                        ifr.ifr_ifindex = a->sll_ifindex;
                        if (ioctl(sockfd, SIOCGIFNAME, &ifr) == 0)
                                ifname = ifr.ifr_name;
                }
                return Py_BuildValue("shbhs#",
                                     ifname,
                                     ntohs(a->sll_protocol),
                                     a->sll_pkttype,
                                     a->sll_hatype,
                                     a->sll_addr,
                                     a->sll_halen);
        }
#endif

        /* More cases here... */

        default:
                /* If we don't know the address family, don't raise an
                   exception -- return it as a tuple. */
                return Py_BuildValue("is#",
                                     addr->sa_family,
                                     addr->sa_data,
                                     sizeof(addr->sa_data));

        }
}


/* Parse a socket address argument according to the socket object's
   address family.  Return 1 if the address was in the proper format,
   0 of not.  The address is returned through addr_ret, its length
   through len_ret. */

static int
getsockaddrarg(PySocketSockObject *s, PyObject *args,
               struct sockaddr *addr_ret, int *len_ret)
{
        switch (s->sock_family) {

#if defined(AF_UNIX)
        case AF_UNIX:
        {
                struct sockaddr_un* addr;
                char *path;
                int len;
                if (!PyArg_Parse(args, "t#", &path, &len))
                        return 0;

                addr = (struct sockaddr_un*)addr_ret;
#ifdef linux
                if (len > 0 && path[0] == 0) {
                        /* Linux abstract namespace extension */
                        if (len > sizeof addr->sun_path) {
                                PyErr_SetString(socket_error,
                                                "AF_UNIX path too long");
                                return 0;
                        }
                }
                else
#endif /* linux */
                {
                        /* regular NULL-terminated string */
                        if (len >= sizeof addr->sun_path) {
                                PyErr_SetString(socket_error,
                                                "AF_UNIX path too long");
                                return 0;
                        }
                        addr->sun_path[len] = 0;
                }
                addr->sun_family = s->sock_family;
                memcpy(addr->sun_path, path, len);
#if defined(PYOS_OS2)
                *len_ret = sizeof(*addr);
#else
                *len_ret = len + sizeof(*addr) - sizeof(addr->sun_path);
#endif
                return 1;
        }
#endif /* AF_UNIX */

#if defined(AF_NETLINK)
        case AF_NETLINK:
        {
                struct sockaddr_nl* addr;
                int pid, groups;
                addr = (struct sockaddr_nl *)addr_ret;
                if (!PyTuple_Check(args)) {
                        PyErr_Format(
                                PyExc_TypeError,
                                "getsockaddrarg: "
                                "AF_NETLINK address must be tuple, not %.500s",
                                Py_Type(args)->tp_name);
                        return 0;
                }
                if (!PyArg_ParseTuple(args, "II:getsockaddrarg", &pid, &groups))
                        return 0;
                addr->nl_family = AF_NETLINK;
                addr->nl_pid = pid;
                addr->nl_groups = groups;
                *len_ret = sizeof(*addr);
                return 1;
        }
#endif

        case AF_INET:
        {
                struct sockaddr_in* addr;
                char *host;
                int port, result;
                if (!PyTuple_Check(args)) {
                        PyErr_Format(
                                PyExc_TypeError,
                                "getsockaddrarg: "
                                "AF_INET address must be tuple, not %.500s",
                                Py_Type(args)->tp_name);
                        return 0;
                }
                if (!PyArg_ParseTuple(args, "eti:getsockaddrarg",
                                      "idna", &host, &port))
                        return 0;
                addr=(struct sockaddr_in*)addr_ret;
                result = setipaddr(host, (struct sockaddr *)addr,
                                   sizeof(*addr),  AF_INET);
                PyMem_Free(host);
                if (result < 0)
                        return 0;
                addr->sin_family = AF_INET;
                addr->sin_port = htons((short)port);
                *len_ret = sizeof *addr;
                return 1;
        }

#ifdef ENABLE_IPV6
        case AF_INET6:
        {
                struct sockaddr_in6* addr;
                char *host;
                int port, flowinfo, scope_id, result;
                flowinfo = scope_id = 0;
                if (!PyTuple_Check(args)) {
                        PyErr_Format(
                                PyExc_TypeError,
                                "getsockaddrarg: "
                                "AF_INET6 address must be tuple, not %.500s",
                                Py_Type(args)->tp_name);
                        return 0;
                }
                if (!PyArg_ParseTuple(args, "eti|ii",
                                      "idna", &host, &port, &flowinfo,
                                      &scope_id)) {
                        return 0;
                }
                addr = (struct sockaddr_in6*)addr_ret;
                result = setipaddr(host, (struct sockaddr *)addr,
                                   sizeof(*addr), AF_INET6);
                PyMem_Free(host);
                if (result < 0)
                        return 0;
                addr->sin6_family = s->sock_family;
                addr->sin6_port = htons((short)port);
                addr->sin6_flowinfo = flowinfo;
                addr->sin6_scope_id = scope_id;
                *len_ret = sizeof *addr;
                return 1;
        }
#endif

#ifdef USE_BLUETOOTH
        case AF_BLUETOOTH:
        {
                switch (s->sock_proto) {
                case BTPROTO_L2CAP:
                {
                        struct sockaddr_l2 *addr;
                        char *straddr;

                        addr = (struct sockaddr_l2 *)addr_ret;
                        _BT_L2_MEMB(addr, family) = AF_BLUETOOTH;
                        if (!PyArg_ParseTuple(args, "si", &straddr,
                                              &_BT_L2_MEMB(addr, psm))) {
                                PyErr_SetString(socket_error, "getsockaddrarg: "
                                                "wrong format");
                                return 0;
                        }
                        if (setbdaddr(straddr, &_BT_L2_MEMB(addr, bdaddr)) < 0)
                                return 0;

                        *len_ret = sizeof *addr;
                        return 1;
                }
                case BTPROTO_RFCOMM:
                {
                        struct sockaddr_rc *addr;
                        char *straddr;

                        addr = (struct sockaddr_rc *)addr_ret;
                        _BT_RC_MEMB(addr, family) = AF_BLUETOOTH;
                        if (!PyArg_ParseTuple(args, "si", &straddr,
                                              &_BT_RC_MEMB(addr, channel))) {
                                PyErr_SetString(socket_error, "getsockaddrarg: "
                                                "wrong format");
                                return 0;
                        }
                        if (setbdaddr(straddr, &_BT_RC_MEMB(addr, bdaddr)) < 0)
                                return 0;

                        *len_ret = sizeof *addr;
                        return 1;
                }
                case BTPROTO_HCI:
                {
                        struct sockaddr_hci *addr = (struct sockaddr_hci *)addr_ret;
                        _BT_HCI_MEMB(addr, family) = AF_BLUETOOTH;
                        if (!PyArg_ParseTuple(args, "i", &_BT_HCI_MEMB(addr, dev))) {
                                PyErr_SetString(socket_error, "getsockaddrarg: "
                                                "wrong format");
                                return 0;
                        }
                        *len_ret = sizeof *addr;
                        return 1;
                }
#if !defined(__FreeBSD__)
                case BTPROTO_SCO:
                {
                        struct sockaddr_sco *addr;
                        char *straddr;

                        addr = (struct sockaddr_sco *)addr_ret;
                        _BT_SCO_MEMB(addr, family) = AF_BLUETOOTH;
                        straddr = PyString_AsString(args);
                        if (straddr == NULL) {
                                PyErr_SetString(socket_error, "getsockaddrarg: "
                                                "wrong format");
                                return 0;
                        }
                        if (setbdaddr(straddr, &_BT_SCO_MEMB(addr, bdaddr)) < 0)
                                return 0;

                        *len_ret = sizeof *addr;
                        return 1;
                }
#endif
                default:
                        PyErr_SetString(socket_error, "getsockaddrarg: unknown Bluetooth protocol");
                        return 0;
                }
        }
#endif

#ifdef HAVE_NETPACKET_PACKET_H
        case AF_PACKET:
        {
                struct sockaddr_ll* addr;
                struct ifreq ifr;
                char *interfaceName;
                int protoNumber;
                int hatype = 0;
                int pkttype = 0;
                char *haddr = NULL;
                unsigned int halen = 0;

                if (!PyTuple_Check(args)) {
                        PyErr_Format(
                                PyExc_TypeError,
                                "getsockaddrarg: "
                                "AF_PACKET address must be tuple, not %.500s",
                                Py_Type(args)->tp_name);
                        return 0;
                }
                if (!PyArg_ParseTuple(args, "si|iis#", &interfaceName,
                                      &protoNumber, &pkttype, &hatype,
                                      &haddr, &halen))
                        return 0;
                strncpy(ifr.ifr_name, interfaceName, sizeof(ifr.ifr_name));
                ifr.ifr_name[(sizeof(ifr.ifr_name))-1] = '\0';
                if (ioctl(s->sock_fd, SIOCGIFINDEX, &ifr) < 0) {
                        s->errorhandler();
                        return 0;
                }
                if (halen > 8) {
                  PyErr_SetString(PyExc_ValueError,
                                  "Hardware address must be 8 bytes or less");
                  return 0;
                }
                addr = (struct sockaddr_ll*)addr_ret;
                addr->sll_family = AF_PACKET;
                addr->sll_protocol = htons((short)protoNumber);
                addr->sll_ifindex = ifr.ifr_ifindex;
                addr->sll_pkttype = pkttype;
                addr->sll_hatype = hatype;
                if (halen != 0) {
                  memcpy(&addr->sll_addr, haddr, halen);
                }
                addr->sll_halen = halen;
                *len_ret = sizeof *addr;
                return 1;
        }
#endif

        /* More cases here... */

        default:
                PyErr_SetString(socket_error, "getsockaddrarg: bad family");
                return 0;

        }
}


/* Get the address length according to the socket object's address family.
   Return 1 if the family is known, 0 otherwise.  The length is returned
   through len_ret. */

static int
getsockaddrlen(PySocketSockObject *s, socklen_t *len_ret)
{
        switch (s->sock_family) {

#if defined(AF_UNIX)
        case AF_UNIX:
        {
                *len_ret = sizeof (struct sockaddr_un);
                return 1;
        }
#endif /* AF_UNIX */
#if defined(AF_NETLINK)
       case AF_NETLINK:
       {
               *len_ret = sizeof (struct sockaddr_nl);
               return 1;
       }
#endif

        case AF_INET:
        {
                *len_ret = sizeof (struct sockaddr_in);
                return 1;
        }

#ifdef ENABLE_IPV6
        case AF_INET6:
        {
                *len_ret = sizeof (struct sockaddr_in6);
                return 1;
        }
#endif

#ifdef USE_BLUETOOTH
        case AF_BLUETOOTH:
        {
                switch(s->sock_proto)
                {

                case BTPROTO_L2CAP:
                        *len_ret = sizeof (struct sockaddr_l2);
                        return 1;
                case BTPROTO_RFCOMM:
                        *len_ret = sizeof (struct sockaddr_rc);
                        return 1;
                case BTPROTO_HCI:
                        *len_ret = sizeof (struct sockaddr_hci);
                        return 1;
#if !defined(__FreeBSD__)
                case BTPROTO_SCO:
                        *len_ret = sizeof (struct sockaddr_sco);
                        return 1;
#endif
                default:
                        PyErr_SetString(socket_error, "getsockaddrlen: "
                                        "unknown BT protocol");
                        return 0;

                }
        }
#endif

#ifdef HAVE_NETPACKET_PACKET_H
        case AF_PACKET:
        {
                *len_ret = sizeof (struct sockaddr_ll);
                return 1;
        }
#endif

        /* More cases here... */

        default:
                PyErr_SetString(socket_error, "getsockaddrlen: bad family");
                return 0;

        }
}


/* s.accept() method */

static PyObject *
sock_accept(PySocketSockObject *s)
{
        sock_addr_t addrbuf;
        SOCKET_T newfd;
        socklen_t addrlen;
        PyObject *sock = NULL;
        PyObject *addr = NULL;
        PyObject *res = NULL;
        int timeout;

        if (!getsockaddrlen(s, &addrlen))
                return NULL;
        memset(&addrbuf, 0, addrlen);

#ifdef MS_WINDOWS
        newfd = INVALID_SOCKET;
#else
        newfd = -1;
#endif

        if (!IS_SELECTABLE(s))
                return select_error();

        Py_BEGIN_ALLOW_THREADS
        timeout = internal_select(s, 0);
        if (!timeout)
                newfd = accept(s->sock_fd, SAS2SA(&addrbuf), &addrlen);
        Py_END_ALLOW_THREADS

        if (timeout == 1) {
                PyErr_SetString(socket_timeout, "timed out");
                return NULL;
        }

#ifdef MS_WINDOWS
        if (newfd == INVALID_SOCKET)
#else
        if (newfd < 0)
#endif
                return s->errorhandler();

        /* Create the new object with unspecified family,
           to avoid calls to bind() etc. on it. */
        sock = (PyObject *) new_sockobject(newfd,
                                           s->sock_family,
                                           s->sock_type,
                                           s->sock_proto);

        if (sock == NULL) {
                SOCKETCLOSE(newfd);
                goto finally;
        }
        addr = makesockaddr(s->sock_fd, SAS2SA(&addrbuf),
                            addrlen, s->sock_proto);
        if (addr == NULL)
                goto finally;

        res = PyTuple_Pack(2, sock, addr);

finally:
        Py_XDECREF(sock);
        Py_XDECREF(addr);
        return res;
}

PyDoc_STRVAR(accept_doc,
"accept() -> (socket object, address info)\n\
\n\
Wait for an incoming connection.  Return a new socket representing the\n\
connection, and the address of the client.  For IP sockets, the address\n\
info is a pair (hostaddr, port).");

/* s.setblocking(flag) method.  Argument:
   False -- non-blocking mode; same as settimeout(0)
   True -- blocking mode; same as settimeout(None)
*/

static PyObject *
sock_setblocking(PySocketSockObject *s, PyObject *arg)
{
        int block;

        block = PyInt_AsLong(arg);
        if (block == -1 && PyErr_Occurred())
                return NULL;

        s->sock_timeout = block ? -1.0 : 0.0;
        internal_setblocking(s, block);

        Py_INCREF(Py_None);
        return Py_None;
}

PyDoc_STRVAR(setblocking_doc,
"setblocking(flag)\n\
\n\
Set the socket to blocking (flag is true) or non-blocking (false).\n\
setblocking(True) is equivalent to settimeout(None);\n\
setblocking(False) is equivalent to settimeout(0.0).");

/* s.settimeout(timeout) method.  Argument:
   None -- no timeout, blocking mode; same as setblocking(True)
   0.0  -- non-blocking mode; same as setblocking(False)
   > 0  -- timeout mode; operations time out after timeout seconds
   < 0  -- illegal; raises an exception
*/
static PyObject *
sock_settimeout(PySocketSockObject *s, PyObject *arg)
{
        double timeout;

        if (arg == Py_None)
                timeout = -1.0;
        else {
                timeout = PyFloat_AsDouble(arg);
                if (timeout < 0.0) {
                        if (!PyErr_Occurred())
                                PyErr_SetString(PyExc_ValueError,
                                                "Timeout value out of range");
                        return NULL;
                }
        }

        s->sock_timeout = timeout;
        internal_setblocking(s, timeout < 0.0);

        Py_INCREF(Py_None);
        return Py_None;
}

PyDoc_STRVAR(settimeout_doc,
"settimeout(timeout)\n\
\n\
Set a timeout on socket operations.  'timeout' can be a float,\n\
giving in seconds, or None.  Setting a timeout of None disables\n\
the timeout feature and is equivalent to setblocking(1).\n\
Setting a timeout of zero is the same as setblocking(0).");

/* s.gettimeout() method.
   Returns the timeout associated with a socket. */
static PyObject *
sock_gettimeout(PySocketSockObject *s)
{
        if (s->sock_timeout < 0.0) {
                Py_INCREF(Py_None);
                return Py_None;
        }
        else
                return PyFloat_FromDouble(s->sock_timeout);
}

PyDoc_STRVAR(gettimeout_doc,
"gettimeout() -> timeout\n\
\n\
Returns the timeout in floating seconds associated with socket \n\
operations. A timeout of None indicates that timeouts on socket \n\
operations are disabled.");

#ifdef RISCOS
/* s.sleeptaskw(1 | 0) method */

static PyObject *
sock_sleeptaskw(PySocketSockObject *s,PyObject *arg)
{
        int block;
        block = PyInt_AsLong(arg);
        if (block == -1 && PyErr_Occurred())
                return NULL;
        Py_BEGIN_ALLOW_THREADS
        socketioctl(s->sock_fd, 0x80046679, (u_long*)&block);
        Py_END_ALLOW_THREADS

        Py_INCREF(Py_None);
        return Py_None;
}
PyDoc_STRVAR(sleeptaskw_doc,
"sleeptaskw(flag)\n\
\n\
Allow sleeps in taskwindows.");
#endif


/* s.setsockopt() method.
   With an integer third argument, sets an integer option.
   With a string third argument, sets an option from a buffer;
   use optional built-in module 'struct' to encode the string. */

static PyObject *
sock_setsockopt(PySocketSockObject *s, PyObject *args)
{
        int level;
        int optname;
        int res;
        char *buf;
        int buflen;
        int flag;

        if (PyArg_ParseTuple(args, "iii:setsockopt",
                             &level, &optname, &flag)) {
                buf = (char *) &flag;
                buflen = sizeof flag;
        }
        else {
                PyErr_Clear();
                if (!PyArg_ParseTuple(args, "iis#:setsockopt",
                                      &level, &optname, &buf, &buflen))
                        return NULL;
        }
        res = setsockopt(s->sock_fd, level, optname, (void *)buf, buflen);
        if (res < 0)
                return s->errorhandler();
        Py_INCREF(Py_None);
        return Py_None;
}

PyDoc_STRVAR(setsockopt_doc,
"setsockopt(level, option, value)\n\
\n\
Set a socket option.  See the Unix manual for level and option.\n\
The value argument can either be an integer or a string.");


/* s.getsockopt() method.
   With two arguments, retrieves an integer option.
   With a third integer argument, retrieves a string buffer of that size;
   use optional built-in module 'struct' to decode the string. */

static PyObject *
sock_getsockopt(PySocketSockObject *s, PyObject *args)
{
        int level;
        int optname;
        int res;
        PyObject *buf;
        socklen_t buflen = 0;

#ifdef __BEOS__
        /* We have incomplete socket support. */
        PyErr_SetString(socket_error, "getsockopt not supported");
        return NULL;
#else

        if (!PyArg_ParseTuple(args, "ii|i:getsockopt",
                              &level, &optname, &buflen))
                return NULL;

        if (buflen == 0) {
                int flag = 0;
                socklen_t flagsize = sizeof flag;
                res = getsockopt(s->sock_fd, level, optname,
                                 (void *)&flag, &flagsize);
                if (res < 0)
                        return s->errorhandler();
                return PyInt_FromLong(flag);
        }
#ifdef __VMS
        /* socklen_t is unsigned so no negative test is needed,
           test buflen == 0 is previously done */
        if (buflen > 1024) {
#else
        if (buflen <= 0 || buflen > 1024) {
#endif
                PyErr_SetString(socket_error,
                                "getsockopt buflen out of range");
                return NULL;
        }
        buf = PyString_FromStringAndSize((char *)NULL, buflen);
        if (buf == NULL)
                return NULL;
        res = getsockopt(s->sock_fd, level, optname,
                         (void *)PyString_AS_STRING(buf), &buflen);
        if (res < 0) {
                Py_DECREF(buf);
                return s->errorhandler();
        }
        _PyString_Resize(&buf, buflen);
        return buf;
#endif /* __BEOS__ */
}

PyDoc_STRVAR(getsockopt_doc,
"getsockopt(level, option[, buffersize]) -> value\n\
\n\
Get a socket option.  See the Unix manual for level and option.\n\
If a nonzero buffersize argument is given, the return value is a\n\
string of that length; otherwise it is an integer.");


/* s.bind(sockaddr) method */

static PyObject *
sock_bind(PySocketSockObject *s, PyObject *addro)
{
        sock_addr_t addrbuf;
        int addrlen;
        int res;

        if (!getsockaddrarg(s, addro, SAS2SA(&addrbuf), &addrlen))
                return NULL;
        Py_BEGIN_ALLOW_THREADS
        res = bind(s->sock_fd, SAS2SA(&addrbuf), addrlen);
        Py_END_ALLOW_THREADS
        if (res < 0)
                return s->errorhandler();
        Py_INCREF(Py_None);
        return Py_None;
}

PyDoc_STRVAR(bind_doc,
"bind(address)\n\
\n\
Bind the socket to a local address.  For IP sockets, the address is a\n\
pair (host, port); the host must refer to the local host. For raw packet\n\
sockets the address is a tuple (ifname, proto [,pkttype [,hatype]])");


/* s.close() method.
   Set the file descriptor to -1 so operations tried subsequently
   will surely fail. */

static PyObject *
sock_close(PySocketSockObject *s)
{
        SOCKET_T fd;

        if ((fd = s->sock_fd) != -1) {
                s->sock_fd = -1;
                Py_BEGIN_ALLOW_THREADS
                (void) SOCKETCLOSE(fd);
                Py_END_ALLOW_THREADS
        }
        Py_INCREF(Py_None);
        return Py_None;
}

PyDoc_STRVAR(close_doc,
"close()\n\
\n\
Close the socket.  It cannot be used after this call.");

static int
internal_connect(PySocketSockObject *s, struct sockaddr *addr, int addrlen,
                 int *timeoutp)
{
        int res, timeout;

        timeout = 0;
        res = connect(s->sock_fd, addr, addrlen);

#ifdef MS_WINDOWS

        if (s->sock_timeout > 0.0) {
                if (res < 0 && WSAGetLastError() == WSAEWOULDBLOCK &&
                    IS_SELECTABLE(s)) {
                        /* This is a mess.  Best solution: trust select */
                        fd_set fds;
                        fd_set fds_exc;
                        struct timeval tv;
                        tv.tv_sec = (int)s->sock_timeout;
                        tv.tv_usec = (int)((s->sock_timeout - tv.tv_sec) * 1e6);
                        FD_ZERO(&fds);
                        FD_SET(s->sock_fd, &fds);
                        FD_ZERO(&fds_exc);
                        FD_SET(s->sock_fd, &fds_exc);
                        res = select(s->sock_fd+1, NULL, &fds, &fds_exc, &tv);
                        if (res == 0) {
                                res = WSAEWOULDBLOCK;
                                timeout = 1;
                        } else if (res > 0) {
                                if (FD_ISSET(s->sock_fd, &fds))
                                        /* The socket is in the writeable set - this
                                           means connected */
                                        res = 0;
                                else {
                                        /* As per MS docs, we need to call getsockopt()
                                           to get the underlying error */
                                        int res_size = sizeof res;
                                        /* It must be in the exception set */
                                        assert(FD_ISSET(s->sock_fd, &fds_exc));
                                        if (0 == getsockopt(s->sock_fd, SOL_SOCKET, SO_ERROR,
                                                            (char *)&res, &res_size))
                                                /* getsockopt also clears WSAGetLastError,
                                                   so reset it back. */
                                                WSASetLastError(res);
                                        else
                                                res = WSAGetLastError();
                                }
                        }
                        /* else if (res < 0) an error occurred */
                }
        }

        if (res < 0)
                res = WSAGetLastError();

#else

        if (s->sock_timeout > 0.0) {
                if (res < 0 && errno == EINPROGRESS && IS_SELECTABLE(s)) {
                        timeout = internal_select(s, 1);
                        if (timeout == 0) {
                                res = connect(s->sock_fd, addr, addrlen);
                                if (res < 0 && errno == EISCONN)
                                        res = 0;
                        }
                        else if (timeout == -1)
                                res = errno;            /* had error */
                        else
                                res = EWOULDBLOCK;      /* timed out */
                }
        }

        if (res < 0)
                res = errno;

#endif
        *timeoutp = timeout;

        return res;
}

/* s.connect(sockaddr) method */

static PyObject *
sock_connect(PySocketSockObject *s, PyObject *addro)
{
        sock_addr_t addrbuf;
        int addrlen;
        int res;
        int timeout;

        if (!getsockaddrarg(s, addro, SAS2SA(&addrbuf), &addrlen))
                return NULL;

        Py_BEGIN_ALLOW_THREADS
        res = internal_connect(s, SAS2SA(&addrbuf), addrlen, &timeout);
        Py_END_ALLOW_THREADS

        if (timeout == 1) {
                PyErr_SetString(socket_timeout, "timed out");
                return NULL;
        }
        if (res != 0)
                return s->errorhandler();
        Py_INCREF(Py_None);
        return Py_None;
}

PyDoc_STRVAR(connect_doc,
"connect(address)\n\
\n\
Connect the socket to a remote address.  For IP sockets, the address\n\
is a pair (host, port).");


/* s.connect_ex(sockaddr) method */

static PyObject *
sock_connect_ex(PySocketSockObject *s, PyObject *addro)
{
        sock_addr_t addrbuf;
        int addrlen;
        int res;
        int timeout;

        if (!getsockaddrarg(s, addro, SAS2SA(&addrbuf), &addrlen))
                return NULL;

        Py_BEGIN_ALLOW_THREADS
        res = internal_connect(s, SAS2SA(&addrbuf), addrlen, &timeout);
        Py_END_ALLOW_THREADS

        /* Signals are not errors (though they may raise exceptions).  Adapted
           from PyErr_SetFromErrnoWithFilenameObject(). */
#ifdef EINTR
        if (res == EINTR && PyErr_CheckSignals())
                return NULL;
#endif

        return PyInt_FromLong((long) res);
}

PyDoc_STRVAR(connect_ex_doc,
"connect_ex(address) -> errno\n\
\n\
This is like connect(address), but returns an error code (the errno value)\n\
instead of raising an exception when an error occurs.");


/* s.fileno() method */

static PyObject *
sock_fileno(PySocketSockObject *s)
{
#if SIZEOF_SOCKET_T <= SIZEOF_LONG
        return PyInt_FromLong((long) s->sock_fd);
#else
        return PyLong_FromLongLong((PY_LONG_LONG)s->sock_fd);
#endif
}

PyDoc_STRVAR(fileno_doc,
"fileno() -> integer\n\
\n\
Return the integer file descriptor of the socket.");


#ifndef NO_DUP
/* s.dup() method */

static PyObject *
sock_dup(PySocketSockObject *s)
{
        SOCKET_T newfd;
        PyObject *sock;

        newfd = dup(s->sock_fd);
        if (newfd < 0)
                return s->errorhandler();
        sock = (PyObject *) new_sockobject(newfd,
                                           s->sock_family,
                                           s->sock_type,
                                           s->sock_proto);
        if (sock == NULL)
                SOCKETCLOSE(newfd);
        return sock;
}

PyDoc_STRVAR(dup_doc,
"dup() -> socket object\n\
\n\
Return a new socket object connected to the same system resource.");

#endif


/* s.getsockname() method */

static PyObject *
sock_getsockname(PySocketSockObject *s)
{
        sock_addr_t addrbuf;
        int res;
        socklen_t addrlen;

        if (!getsockaddrlen(s, &addrlen))
                return NULL;
        memset(&addrbuf, 0, addrlen);
        Py_BEGIN_ALLOW_THREADS
        res = getsockname(s->sock_fd, SAS2SA(&addrbuf), &addrlen);
        Py_END_ALLOW_THREADS
        if (res < 0)
                return s->errorhandler();
        return makesockaddr(s->sock_fd, SAS2SA(&addrbuf), addrlen,
                            s->sock_proto);
}

PyDoc_STRVAR(getsockname_doc,
"getsockname() -> address info\n\
\n\
Return the address of the local endpoint.  For IP sockets, the address\n\
info is a pair (hostaddr, port).");


#ifdef HAVE_GETPEERNAME         /* Cray APP doesn't have this :-( */
/* s.getpeername() method */

static PyObject *
sock_getpeername(PySocketSockObject *s)
{
        sock_addr_t addrbuf;
        int res;
        socklen_t addrlen;

        if (!getsockaddrlen(s, &addrlen))
                return NULL;
        memset(&addrbuf, 0, addrlen);
        Py_BEGIN_ALLOW_THREADS
        res = getpeername(s->sock_fd, SAS2SA(&addrbuf), &addrlen);
        Py_END_ALLOW_THREADS
        if (res < 0)
                return s->errorhandler();
        return makesockaddr(s->sock_fd, SAS2SA(&addrbuf), addrlen,
                            s->sock_proto);
}

PyDoc_STRVAR(getpeername_doc,
"getpeername() -> address info\n\
\n\
Return the address of the remote endpoint.  For IP sockets, the address\n\
info is a pair (hostaddr, port).");

#endif /* HAVE_GETPEERNAME */


/* s.listen(n) method */

static PyObject *
sock_listen(PySocketSockObject *s, PyObject *arg)
{
        int backlog;
        int res;

        backlog = PyInt_AsLong(arg);
        if (backlog == -1 && PyErr_Occurred())
                return NULL;
        Py_BEGIN_ALLOW_THREADS
        if (backlog < 1)
                backlog = 1;
        res = listen(s->sock_fd, backlog);
        Py_END_ALLOW_THREADS
        if (res < 0)
                return s->errorhandler();
        Py_INCREF(Py_None);
        return Py_None;
}

PyDoc_STRVAR(listen_doc,
"listen(backlog)\n\
\n\
Enable a server to accept connections.  The backlog argument must be at\n\
least 1; it specifies the number of unaccepted connection that the system\n\
will allow before refusing new connections.");


#ifndef NO_DUP
/* s.makefile(mode) method.
   Create a new open file object referring to a dupped version of
   the socket's file descriptor.  (The dup() call is necessary so
   that the open file and socket objects may be closed independent
   of each other.)
   The mode argument specifies 'r' or 'w' passed to fdopen(). */

static PyObject *
sock_makefile(PySocketSockObject *s, PyObject *args)
{
        extern int fclose(FILE *);
        char *mode = "r";
        int bufsize = -1;
#ifdef MS_WIN32
        Py_intptr_t fd;
#else
        int fd;
#endif
        FILE *fp;
        PyObject *f;
#ifdef __VMS
        char *mode_r = "r";
        char *mode_w = "w";
#endif

        if (!PyArg_ParseTuple(args, "|si:makefile", &mode, &bufsize))
                return NULL;
#ifdef __VMS
        if (strcmp(mode,"rb") == 0) {
            mode = mode_r;
        }
        else {
                if (strcmp(mode,"wb") == 0) {
                        mode = mode_w;
                }
        }
#endif
#ifdef MS_WIN32
        if (((fd = _open_osfhandle(s->sock_fd, _O_BINARY)) < 0) ||
            ((fd = dup(fd)) < 0) || ((fp = fdopen(fd, mode)) == NULL))
#else
        if ((fd = dup(s->sock_fd)) < 0 || (fp = fdopen(fd, mode)) == NULL)
#endif
        {
                if (fd >= 0)
                        SOCKETCLOSE(fd);
                return s->errorhandler();
        }
        f = PyFile_FromFile(fp, "<socket>", mode, fclose);
        if (f != NULL)
                PyFile_SetBufSize(f, bufsize);
        return f;
}

PyDoc_STRVAR(makefile_doc,
"makefile([mode[, buffersize]]) -> file object\n\
\n\
Return a regular file object corresponding to the socket.\n\
The mode and buffersize arguments are as for the built-in open() function.");

#endif /* NO_DUP */

/*
 * This is the guts of the recv() and recv_into() methods, which reads into a
 * char buffer.  If you have any inc/dec ref to do to the objects that contain
 * the buffer, do it in the caller.  This function returns the number of bytes
 * succesfully read.  If there was an error, it returns -1.  Note that it is
 * also possible that we return a number of bytes smaller than the request
 * bytes.
 */
static ssize_t
sock_recv_guts(PySocketSockObject *s, char* cbuf, int len, int flags)
{
        ssize_t outlen = -1;
        int timeout;
#ifdef __VMS
        int remaining;
        char *read_buf;
#endif

        if (!IS_SELECTABLE(s)) {
                select_error();
                return -1;
        }

#ifndef __VMS
        Py_BEGIN_ALLOW_THREADS
        timeout = internal_select(s, 0);
        if (!timeout)
                outlen = recv(s->sock_fd, cbuf, len, flags);
        Py_END_ALLOW_THREADS

        if (timeout == 1) {
                PyErr_SetString(socket_timeout, "timed out");
                return -1;
        }
        if (outlen < 0) {
                /* Note: the call to errorhandler() ALWAYS indirectly returned
                   NULL, so ignore its return value */
                s->errorhandler();
                return -1;
        }
#else
        read_buf = cbuf;
        remaining = len;
        while (remaining != 0) {
                unsigned int segment;
                int nread = -1;

                segment = remaining /SEGMENT_SIZE;
                if (segment != 0) {
                        segment = SEGMENT_SIZE;
                }
                else {
                        segment = remaining;
                }

                Py_BEGIN_ALLOW_THREADS
                timeout = internal_select(s, 0);
                if (!timeout)
                        nread = recv(s->sock_fd, read_buf, segment, flags);
                Py_END_ALLOW_THREADS

                if (timeout == 1) {
                        PyErr_SetString(socket_timeout, "timed out");
                        return -1;
                }
                if (nread < 0) {
                        s->errorhandler();
                        return -1;
                }
                if (nread != remaining) {
                        read_buf += nread;
                        break;
                }

                remaining -= segment;
                read_buf += segment;
        }
        outlen = read_buf - cbuf;
#endif /* !__VMS */

        return outlen;
}


/* s.recv(nbytes [,flags]) method */

static PyObject *
sock_recv(PySocketSockObject *s, PyObject *args)
{
        int recvlen, flags = 0;
        ssize_t outlen;
        PyObject *buf;

        if (!PyArg_ParseTuple(args, "i|i:recv", &recvlen, &flags))
                return NULL;

        if (recvlen < 0) {
                PyErr_SetString(PyExc_ValueError,
                                "negative buffersize in recv");
                return NULL;
        }

        /* Allocate a new string. */
        buf = PyString_FromStringAndSize((char *) 0, recvlen);
        if (buf == NULL)
                return NULL;

        /* Call the guts */
        outlen = sock_recv_guts(s, PyString_AS_STRING(buf), recvlen, flags);
        if (outlen < 0) {
                /* An error occurred, release the string and return an
                   error. */
                Py_DECREF(buf);
                return NULL;
        }
        if (outlen != recvlen) {
                /* We did not read as many bytes as we anticipated, resize the
                   string if possible and be succesful. */
                if (_PyString_Resize(&buf, outlen) < 0)
                        /* Oopsy, not so succesful after all. */
                        return NULL;
        }

        return buf;
}

PyDoc_STRVAR(recv_doc,
"recv(buffersize[, flags]) -> data\n\
\n\
Receive up to buffersize bytes from the socket.  For the optional flags\n\
argument, see the Unix manual.  When no data is available, block until\n\
at least one byte is available or until the remote end is closed.  When\n\
the remote end is closed and all data is read, return the empty string.");


/* s.recv_into(buffer, [nbytes [,flags]]) method */

static PyObject*
sock_recv_into(PySocketSockObject *s, PyObject *args, PyObject *kwds)
{
        static char *kwlist[] = {"buffer", "nbytes", "flags", 0};

        int recvlen = 0, flags = 0;
        ssize_t readlen;
        char *buf;
        int buflen;

        /* Get the buffer's memory */
        if (!PyArg_ParseTupleAndKeywords(args, kwds, "w#|ii:recv_into", kwlist,
                                         &buf, &buflen, &recvlen, &flags))
                return NULL;
        assert(buf != 0 && buflen > 0);

        if (recvlen < 0) {
                PyErr_SetString(PyExc_ValueError,
                                "negative buffersize in recv_into");
                return NULL;
        }
        if (recvlen == 0) {
            /* If nbytes was not specified, use the buffer's length */
            recvlen = buflen;
        }

        /* Check if the buffer is large enough */
        if (buflen < recvlen) {
                PyErr_SetString(PyExc_ValueError,
                                "buffer too small for requested bytes");
                return NULL;
        }

        /* Call the guts */
        readlen = sock_recv_guts(s, buf, recvlen, flags);
        if (readlen < 0) {
                /* Return an error. */
                return NULL;
        }

        /* Return the number of bytes read.  Note that we do not do anything
           special here in the case that readlen < recvlen. */
        return PyInt_FromSsize_t(readlen);
}

PyDoc_STRVAR(recv_into_doc,
"recv_into(buffer, [nbytes[, flags]]) -> nbytes_read\n\
\n\
A version of recv() that stores its data into a buffer rather than creating \n\
a new string.  Receive up to buffersize bytes from the socket.  If buffersize \n\
is not specified (or 0), receive up to the size available in the given buffer.\n\
\n\
See recv() for documentation about the flags.");


/*
 * This is the guts of the recv() and recv_into() methods, which reads into a
 * char buffer.  If you have any inc/def ref to do to the objects that contain
 * the buffer, do it in the caller.  This function returns the number of bytes
 * succesfully read.  If there was an error, it returns -1.  Note that it is
 * also possible that we return a number of bytes smaller than the request
 * bytes.
 *
 * 'addr' is a return value for the address object.  Note that you must decref
 * it yourself.
 */
static ssize_t
sock_recvfrom_guts(PySocketSockObject *s, char* cbuf, int len, int flags,
                   PyObject** addr)
{
        sock_addr_t addrbuf;
        int timeout;
        ssize_t n = -1;
        socklen_t addrlen;

        *addr = NULL;

        if (!getsockaddrlen(s, &addrlen))
                return -1;

        if (!IS_SELECTABLE(s)) {
                select_error();
                return -1;
        }

        Py_BEGIN_ALLOW_THREADS
        memset(&addrbuf, 0, addrlen);
        timeout = internal_select(s, 0);
        if (!timeout) {
#ifndef MS_WINDOWS
#if defined(PYOS_OS2) && !defined(PYCC_GCC)
                n = recvfrom(s->sock_fd, cbuf, len, flags,
                             SAS2SA(&addrbuf), &addrlen);
#else
                n = recvfrom(s->sock_fd, cbuf, len, flags,
                             (void *) &addrbuf, &addrlen);
#endif
#else
                n = recvfrom(s->sock_fd, cbuf, len, flags,
                             SAS2SA(&addrbuf), &addrlen);
#endif
        }
        Py_END_ALLOW_THREADS

        if (timeout == 1) {
                PyErr_SetString(socket_timeout, "timed out");
                return -1;
        }
        if (n < 0) {
                s->errorhandler();
                return -1;
        }

        if (!(*addr = makesockaddr(s->sock_fd, SAS2SA(&addrbuf),
                                   addrlen, s->sock_proto)))
                return -1;

        return n;
}

/* s.recvfrom(nbytes [,flags]) method */

static PyObject *
sock_recvfrom(PySocketSockObject *s, PyObject *args)
{
        PyObject *buf = NULL;
        PyObject *addr = NULL;
        PyObject *ret = NULL;
        int recvlen, flags = 0;
        ssize_t outlen;

        if (!PyArg_ParseTuple(args, "i|i:recvfrom", &recvlen, &flags))
                return NULL;

        if (recvlen < 0) {
                PyErr_SetString(PyExc_ValueError,
                                "negative buffersize in recvfrom");
                return NULL;
        }

        buf = PyString_FromStringAndSize((char *) 0, recvlen);
        if (buf == NULL)
                return NULL;

        outlen = sock_recvfrom_guts(s, PyString_AS_STRING(buf),
                                    recvlen, flags, &addr);
        if (outlen < 0) {
                goto finally;
        }

        if (outlen != recvlen) {
                /* We did not read as many bytes as we anticipated, resize the
                   string if possible and be succesful. */
                if (_PyString_Resize(&buf, outlen) < 0)
                        /* Oopsy, not so succesful after all. */
                        goto finally;
        }

        ret = PyTuple_Pack(2, buf, addr);

finally:
        Py_XDECREF(buf);
        Py_XDECREF(addr);
        return ret;
}

PyDoc_STRVAR(recvfrom_doc,
"recvfrom(buffersize[, flags]) -> (data, address info)\n\
\n\
Like recv(buffersize, flags) but also return the sender's address info.");


/* s.recvfrom_into(buffer[, nbytes [,flags]]) method */

static PyObject *
sock_recvfrom_into(PySocketSockObject *s, PyObject *args, PyObject* kwds)
{
        static char *kwlist[] = {"buffer", "nbytes", "flags", 0};

        int recvlen = 0, flags = 0;
        ssize_t readlen;
        char *buf;
        int buflen;

        PyObject *addr = NULL;

        if (!PyArg_ParseTupleAndKeywords(args, kwds, "w#|ii:recvfrom_into",
                                         kwlist, &buf, &buflen,
                                         &recvlen, &flags))
                return NULL;
        assert(buf != 0 && buflen > 0);

        if (recvlen < 0) {
                PyErr_SetString(PyExc_ValueError,
                                "negative buffersize in recvfrom_into");
                return NULL;
        }
        if (recvlen == 0) {
            /* If nbytes was not specified, use the buffer's length */
            recvlen = buflen;
        }

        readlen = sock_recvfrom_guts(s, buf, recvlen, flags, &addr);
        if (readlen < 0) {
                /* Return an error */
                Py_XDECREF(addr);
                return NULL;
        }

        /* Return the number of bytes read and the address.  Note that we do
           not do anything special here in the case that readlen < recvlen. */
        return Py_BuildValue("lN", readlen, addr);
}

PyDoc_STRVAR(recvfrom_into_doc,
"recvfrom_into(buffer[, nbytes[, flags]]) -> (nbytes, address info)\n\
\n\
Like recv_into(buffer[, nbytes[, flags]]) but also return the sender's address info.");


/* s.send(data [,flags]) method */

static PyObject *
sock_send(PySocketSockObject *s, PyObject *args)
{
        char *buf;
        int len, n = -1, flags = 0, timeout;

        if (!PyArg_ParseTuple(args, "s#|i:send", &buf, &len, &flags))
                return NULL;

        if (!IS_SELECTABLE(s))
                return select_error();

        Py_BEGIN_ALLOW_THREADS
        timeout = internal_select(s, 1);
        if (!timeout)
#ifdef __VMS
                n = sendsegmented(s->sock_fd, buf, len, flags);
#else
                n = send(s->sock_fd, buf, len, flags);
#endif
        Py_END_ALLOW_THREADS

        if (timeout == 1) {
                PyErr_SetString(socket_timeout, "timed out");
                return NULL;
        }
        if (n < 0)
                return s->errorhandler();
        return PyInt_FromLong((long)n);
}

PyDoc_STRVAR(send_doc,
"send(data[, flags]) -> count\n\
\n\
Send a data string to the socket.  For the optional flags\n\
argument, see the Unix manual.  Return the number of bytes\n\
sent; this may be less than len(data) if the network is busy.");


/* s.sendall(data [,flags]) method */

static PyObject *
sock_sendall(PySocketSockObject *s, PyObject *args)
{
        char *buf;
        int len, n = -1, flags = 0, timeout;

        if (!PyArg_ParseTuple(args, "s#|i:sendall", &buf, &len, &flags))
                return NULL;

        if (!IS_SELECTABLE(s))
                return select_error();

        Py_BEGIN_ALLOW_THREADS
        do {
                timeout = internal_select(s, 1);
                n = -1;
                if (timeout)
                        break;
#ifdef __VMS
                n = sendsegmented(s->sock_fd, buf, len, flags);
#else
                n = send(s->sock_fd, buf, len, flags);
#endif
                if (n < 0)
                        break;
                buf += n;
                len -= n;
        } while (len > 0);
        Py_END_ALLOW_THREADS

        if (timeout == 1) {
                PyErr_SetString(socket_timeout, "timed out");
                return NULL;
        }
        if (n < 0)
                return s->errorhandler();

        Py_INCREF(Py_None);
        return Py_None;
}

PyDoc_STRVAR(sendall_doc,
"sendall(data[, flags])\n\
\n\
Send a data string to the socket.  For the optional flags\n\
argument, see the Unix manual.  This calls send() repeatedly\n\
until all data is sent.  If an error occurs, it's impossible\n\
to tell how much data has been sent.");


/* s.sendto(data, [flags,] sockaddr) method */

static PyObject *
sock_sendto(PySocketSockObject *s, PyObject *args)
{
        PyObject *addro;
        char *buf;
        sock_addr_t addrbuf;
        int addrlen, len, n = -1, flags, timeout;

        flags = 0;
        if (!PyArg_ParseTuple(args, "s#O:sendto", &buf, &len, &addro)) {
                PyErr_Clear();
                if (!PyArg_ParseTuple(args, "s#iO:sendto",
                                      &buf, &len, &flags, &addro))
                        return NULL;
        }

        if (!IS_SELECTABLE(s))
                return select_error();

        if (!getsockaddrarg(s, addro, SAS2SA(&addrbuf), &addrlen))
                return NULL;

        Py_BEGIN_ALLOW_THREADS
        timeout = internal_select(s, 1);
        if (!timeout)
                n = sendto(s->sock_fd, buf, len, flags, SAS2SA(&addrbuf), addrlen);
        Py_END_ALLOW_THREADS

        if (timeout == 1) {
                PyErr_SetString(socket_timeout, "timed out");
                return NULL;
        }
        if (n < 0)
                return s->errorhandler();
        return PyInt_FromLong((long)n);
}

PyDoc_STRVAR(sendto_doc,
"sendto(data[, flags], address) -> count\n\
\n\
Like send(data, flags) but allows specifying the destination address.\n\
For IP sockets, the address is a pair (hostaddr, port).");


/* s.shutdown(how) method */

static PyObject *
sock_shutdown(PySocketSockObject *s, PyObject *arg)
{
        int how;
        int res;

        how = PyInt_AsLong(arg);
        if (how == -1 && PyErr_Occurred())
                return NULL;
        Py_BEGIN_ALLOW_THREADS
        res = shutdown(s->sock_fd, how);
        Py_END_ALLOW_THREADS
        if (res < 0)
                return s->errorhandler();
        Py_INCREF(Py_None);
        return Py_None;
}

PyDoc_STRVAR(shutdown_doc,
"shutdown(flag)\n\
\n\
Shut down the reading side of the socket (flag == SHUT_RD), the writing side\n\
of the socket (flag == SHUT_WR), or both ends (flag == SHUT_RDWR).");


/* List of methods for socket objects */

static PyMethodDef sock_methods[] = {
        {"accept",        (PyCFunction)sock_accept, METH_NOARGS,
                          accept_doc},
        {"bind",          (PyCFunction)sock_bind, METH_O,
                          bind_doc},
        {"close",         (PyCFunction)sock_close, METH_NOARGS,
                          close_doc},
        {"connect",       (PyCFunction)sock_connect, METH_O,
                          connect_doc},
        {"connect_ex",    (PyCFunction)sock_connect_ex, METH_O,
                          connect_ex_doc},
#ifndef NO_DUP
        {"dup",           (PyCFunction)sock_dup, METH_NOARGS,
                          dup_doc},
#endif
        {"fileno",        (PyCFunction)sock_fileno, METH_NOARGS,
                          fileno_doc},
#ifdef HAVE_GETPEERNAME
        {"getpeername",   (PyCFunction)sock_getpeername,
                          METH_NOARGS, getpeername_doc},
#endif
        {"getsockname",   (PyCFunction)sock_getsockname,
                          METH_NOARGS, getsockname_doc},
        {"getsockopt",    (PyCFunction)sock_getsockopt, METH_VARARGS,
                          getsockopt_doc},
        {"listen",        (PyCFunction)sock_listen, METH_O,
                          listen_doc},
#ifndef NO_DUP
        {"makefile",      (PyCFunction)sock_makefile, METH_VARARGS,
                          makefile_doc},
#endif
        {"recv",          (PyCFunction)sock_recv, METH_VARARGS,
                          recv_doc},
        {"recv_into",     (PyCFunction)sock_recv_into, METH_VARARGS | METH_KEYWORDS,
                          recv_into_doc},
        {"recvfrom",      (PyCFunction)sock_recvfrom, METH_VARARGS,
                          recvfrom_doc},
        {"recvfrom_into",  (PyCFunction)sock_recvfrom_into, METH_VARARGS | METH_KEYWORDS,
                          recvfrom_into_doc},
        {"send",          (PyCFunction)sock_send, METH_VARARGS,
                          send_doc},
        {"sendall",       (PyCFunction)sock_sendall, METH_VARARGS,
                          sendall_doc},
        {"sendto",        (PyCFunction)sock_sendto, METH_VARARGS,
                          sendto_doc},
        {"setblocking",   (PyCFunction)sock_setblocking, METH_O,
                          setblocking_doc},
        {"settimeout",    (PyCFunction)sock_settimeout, METH_O,
                          settimeout_doc},
        {"gettimeout",    (PyCFunction)sock_gettimeout, METH_NOARGS,
                          gettimeout_doc},
        {"setsockopt",    (PyCFunction)sock_setsockopt, METH_VARARGS,
                          setsockopt_doc},
        {"shutdown",      (PyCFunction)sock_shutdown, METH_O,
                          shutdown_doc},
#ifdef RISCOS
        {"sleeptaskw",    (PyCFunction)sock_sleeptaskw, METH_O,
                          sleeptaskw_doc},
#endif
        {NULL,                  NULL}           /* sentinel */
};

/* SockObject members */
static PyMemberDef sock_memberlist[] = {
       {"family", T_INT, offsetof(PySocketSockObject, sock_family), READONLY, "the socket family"},
       {"type", T_INT, offsetof(PySocketSockObject, sock_type), READONLY, "the socket type"},
       {"proto", T_INT, offsetof(PySocketSockObject, sock_proto), READONLY, "the socket protocol"},
       {"timeout", T_DOUBLE, offsetof(PySocketSockObject, sock_timeout), READONLY, "the socket timeout"},
       {0},
};

/* Deallocate a socket object in response to the last Py_DECREF().
   First close the file description. */

static void
sock_dealloc(PySocketSockObject *s)
{
        if (s->sock_fd != -1)
                (void) SOCKETCLOSE(s->sock_fd);
        Py_Type(s)->tp_free((PyObject *)s);
}


static PyObject *
sock_repr(PySocketSockObject *s)
{
        char buf[512];
#if SIZEOF_SOCKET_T > SIZEOF_LONG
        if (s->sock_fd > LONG_MAX) {
                /* this can occur on Win64, and actually there is a special
                   ugly printf formatter for decimal pointer length integer
                   printing, only bother if necessary*/
                PyErr_SetString(PyExc_OverflowError,
                                "no printf formatter to display "
                                "the socket descriptor in decimal");
                return NULL;
        }
#endif
        PyOS_snprintf(
                buf, sizeof(buf),
                "<socket object, fd=%ld, family=%d, type=%d, protocol=%d>",
                (long)s->sock_fd, s->sock_family,
                s->sock_type,
                s->sock_proto);
        return PyString_FromString(buf);
}


/* Create a new, uninitialized socket object. */

static PyObject *
sock_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
        PyObject *new;

        new = type->tp_alloc(type, 0);
        if (new != NULL) {
                ((PySocketSockObject *)new)->sock_fd = -1;
                ((PySocketSockObject *)new)->sock_timeout = -1.0;
                ((PySocketSockObject *)new)->errorhandler = &set_error;
        }
        return new;
}


/* Initialize a new socket object. */

/*ARGSUSED*/
static int
sock_initobj(PyObject *self, PyObject *args, PyObject *kwds)
{
        PySocketSockObject *s = (PySocketSockObject *)self;
        SOCKET_T fd;
        int family = AF_INET, type = SOCK_STREAM, proto = 0;
        static char *keywords[] = {"family", "type", "proto", 0};

        if (!PyArg_ParseTupleAndKeywords(args, kwds,
                                         "|iii:socket", keywords,
                                         &family, &type, &proto))
                return -1;

        Py_BEGIN_ALLOW_THREADS
        fd = socket(family, type, proto);
        Py_END_ALLOW_THREADS

#ifdef MS_WINDOWS
        if (fd == INVALID_SOCKET)
#else
        if (fd < 0)
#endif
        {
                set_error();
                return -1;
        }
        init_sockobject(s, fd, family, type, proto);

        return 0;

}


/* Type object for socket objects. */

static PyTypeObject sock_type = {
        PyVarObject_HEAD_INIT(0, 0)     /* Must fill in type value later */
        "_socket.socket",                       /* tp_name */
        sizeof(PySocketSockObject),             /* tp_basicsize */
        0,                                      /* tp_itemsize */
        (destructor)sock_dealloc,               /* tp_dealloc */
        0,                                      /* tp_print */
        0,                                      /* tp_getattr */
        0,                                      /* tp_setattr */
        0,                                      /* tp_compare */
        (reprfunc)sock_repr,                    /* tp_repr */
        0,                                      /* tp_as_number */
        0,                                      /* tp_as_sequence */
        0,                                      /* tp_as_mapping */
        0,                                      /* tp_hash */
        0,                                      /* tp_call */
        0,                                      /* tp_str */
        PyObject_GenericGetAttr,                /* tp_getattro */
        0,                                      /* tp_setattro */
        0,                                      /* tp_as_buffer */
        Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
        sock_doc,                               /* tp_doc */
        0,                                      /* tp_traverse */
        0,                                      /* tp_clear */
        0,                                      /* tp_richcompare */
        0,                                      /* tp_weaklistoffset */
        0,                                      /* tp_iter */
        0,                                      /* tp_iternext */
        sock_methods,                           /* tp_methods */
        sock_memberlist,                        /* tp_members */
        0,                                      /* tp_getset */
        0,                                      /* tp_base */
        0,                                      /* tp_dict */
        0,                                      /* tp_descr_get */
        0,                                      /* tp_descr_set */
        0,                                      /* tp_dictoffset */
        sock_initobj,                           /* tp_init */
        PyType_GenericAlloc,                    /* tp_alloc */
        sock_new,                               /* tp_new */
        PyObject_Del,                           /* tp_free */
};


/* Python interface to gethostname(). */

/*ARGSUSED*/
static PyObject *
socket_gethostname(PyObject *self, PyObject *unused)
{
        char buf[1024];
        int res;
        Py_BEGIN_ALLOW_THREADS
        res = gethostname(buf, (int) sizeof buf - 1);
        Py_END_ALLOW_THREADS
        if (res < 0)
                return set_error();
        buf[sizeof buf - 1] = '\0';
        return PyString_FromString(buf);
}

PyDoc_STRVAR(gethostname_doc,
"gethostname() -> string\n\
\n\
Return the current host name.");


/* Python interface to gethostbyname(name). */

/*ARGSUSED*/
static PyObject *
socket_gethostbyname(PyObject *self, PyObject *args)
{
        char *name;
        sock_addr_t addrbuf;

        if (!PyArg_ParseTuple(args, "s:gethostbyname", &name))
                return NULL;
        if (setipaddr(name, SAS2SA(&addrbuf),  sizeof(addrbuf), AF_INET) < 0)
                return NULL;
        return makeipaddr(SAS2SA(&addrbuf), sizeof(struct sockaddr_in));
}

PyDoc_STRVAR(gethostbyname_doc,
"gethostbyname(host) -> address\n\
\n\
Return the IP address (a string of the form '255.255.255.255') for a host.");


/* Convenience function common to gethostbyname_ex and gethostbyaddr */

static PyObject *
gethost_common(struct hostent *h, struct sockaddr *addr, int alen, int af)
{
        char **pch;
        PyObject *rtn_tuple = (PyObject *)NULL;
        PyObject *name_list = (PyObject *)NULL;
        PyObject *addr_list = (PyObject *)NULL;
        PyObject *tmp;

        if (h == NULL) {
                /* Let's get real error message to return */
#ifndef RISCOS
                set_herror(h_errno);
#else
                PyErr_SetString(socket_error, "host not found");
#endif
                return NULL;
        }

        if (h->h_addrtype != af) {
#ifdef HAVE_STRERROR
                /* Let's get real error message to return */
                PyErr_SetString(socket_error,
                                (char *)strerror(EAFNOSUPPORT));
#else
                PyErr_SetString(
                        socket_error,
                        "Address family not supported by protocol family");
#endif
                return NULL;
        }

        switch (af) {

        case AF_INET:
                if (alen < sizeof(struct sockaddr_in))
                        return NULL;
                break;

#ifdef ENABLE_IPV6
        case AF_INET6:
                if (alen < sizeof(struct sockaddr_in6))
                        return NULL;
                break;
#endif

        }

        if ((name_list = PyList_New(0)) == NULL)
                goto err;

        if ((addr_list = PyList_New(0)) == NULL)
                goto err;

        /* SF #1511317: h_aliases can be NULL */
        if (h->h_aliases) {
                for (pch = h->h_aliases; *pch != NULL; pch++) {
                        int status;
                        tmp = PyString_FromString(*pch);
                        if (tmp == NULL)
                                goto err;

                        status = PyList_Append(name_list, tmp);
                        Py_DECREF(tmp);

                        if (status)
                                goto err;
                }
        }

        for (pch = h->h_addr_list; *pch != NULL; pch++) {
                int status;

                switch (af) {

                case AF_INET:
                    {
                        struct sockaddr_in sin;
                        memset(&sin, 0, sizeof(sin));
                        sin.sin_family = af;
#ifdef HAVE_SOCKADDR_SA_LEN
                        sin.sin_len = sizeof(sin);
#endif
                        memcpy(&sin.sin_addr, *pch, sizeof(sin.sin_addr));
                        tmp = makeipaddr((struct sockaddr *)&sin, sizeof(sin));

                        if (pch == h->h_addr_list && alen >= sizeof(sin))
                                memcpy((char *) addr, &sin, sizeof(sin));
                        break;
                    }

#ifdef ENABLE_IPV6
                case AF_INET6:
                    {
                        struct sockaddr_in6 sin6;
                        memset(&sin6, 0, sizeof(sin6));
                        sin6.sin6_family = af;
#ifdef HAVE_SOCKADDR_SA_LEN
                        sin6.sin6_len = sizeof(sin6);
#endif
                        memcpy(&sin6.sin6_addr, *pch, sizeof(sin6.sin6_addr));
                        tmp = makeipaddr((struct sockaddr *)&sin6,
                                sizeof(sin6));

                        if (pch == h->h_addr_list && alen >= sizeof(sin6))
                                memcpy((char *) addr, &sin6, sizeof(sin6));
                        break;
                    }
#endif

                default:        /* can't happen */
                        PyErr_SetString(socket_error,
                                        "unsupported address family");
                        return NULL;
                }

                if (tmp == NULL)
                        goto err;

                status = PyList_Append(addr_list, tmp);
                Py_DECREF(tmp);

                if (status)
                        goto err;
        }

        rtn_tuple = Py_BuildValue("sOO", h->h_name, name_list, addr_list);

 err:
        Py_XDECREF(name_list);
        Py_XDECREF(addr_list);
        return rtn_tuple;
}


/* Python interface to gethostbyname_ex(name). */

/*ARGSUSED*/
static PyObject *
socket_gethostbyname_ex(PyObject *self, PyObject *args)
{
        char *name;
        struct hostent *h;
#ifdef ENABLE_IPV6
        struct sockaddr_storage addr;
#else
        struct sockaddr_in addr;
#endif
        struct sockaddr *sa;
        PyObject *ret;
#ifdef HAVE_GETHOSTBYNAME_R
        struct hostent hp_allocated;
#ifdef HAVE_GETHOSTBYNAME_R_3_ARG
        struct hostent_data data;
#else
        char buf[16384];
        int buf_len = (sizeof buf) - 1;
        int errnop;
#endif
#if defined(HAVE_GETHOSTBYNAME_R_3_ARG) || defined(HAVE_GETHOSTBYNAME_R_6_ARG)
        int result;
#endif
#endif /* HAVE_GETHOSTBYNAME_R */

        if (!PyArg_ParseTuple(args, "s:gethostbyname_ex", &name))
                return NULL;
        if (setipaddr(name, (struct sockaddr *)&addr, sizeof(addr), AF_INET) < 0)
                return NULL;
        Py_BEGIN_ALLOW_THREADS
#ifdef HAVE_GETHOSTBYNAME_R
#if   defined(HAVE_GETHOSTBYNAME_R_6_ARG)
        result = gethostbyname_r(name, &hp_allocated, buf, buf_len,
                                 &h, &errnop);
#elif defined(HAVE_GETHOSTBYNAME_R_5_ARG)
        h = gethostbyname_r(name, &hp_allocated, buf, buf_len, &errnop);
#else /* HAVE_GETHOSTBYNAME_R_3_ARG */
        memset((void *) &data, '\0', sizeof(data));
        result = gethostbyname_r(name, &hp_allocated, &data);
        h = (result != 0) ? NULL : &hp_allocated;
#endif
#else /* not HAVE_GETHOSTBYNAME_R */
#ifdef USE_GETHOSTBYNAME_LOCK
        PyThread_acquire_lock(netdb_lock, 1);
#endif
        h = gethostbyname(name);
#endif /* HAVE_GETHOSTBYNAME_R */
        Py_END_ALLOW_THREADS
        /* Some C libraries would require addr.__ss_family instead of
           addr.ss_family.
           Therefore, we cast the sockaddr_storage into sockaddr to
           access sa_family. */
        sa = (struct sockaddr*)&addr;
        ret = gethost_common(h, (struct sockaddr *)&addr, sizeof(addr),
                             sa->sa_family);
#ifdef USE_GETHOSTBYNAME_LOCK
        PyThread_release_lock(netdb_lock);
#endif
        return ret;
}

PyDoc_STRVAR(ghbn_ex_doc,
"gethostbyname_ex(host) -> (name, aliaslist, addresslist)\n\
\n\
Return the true host name, a list of aliases, and a list of IP addresses,\n\
for a host.  The host argument is a string giving a host name or IP number.");


/* Python interface to gethostbyaddr(IP). */

/*ARGSUSED*/
static PyObject *
socket_gethostbyaddr(PyObject *self, PyObject *args)
{
#ifdef ENABLE_IPV6
        struct sockaddr_storage addr;
#else
        struct sockaddr_in addr;
#endif
        struct sockaddr *sa = (struct sockaddr *)&addr;
        char *ip_num;
        struct hostent *h;
        PyObject *ret;
#ifdef HAVE_GETHOSTBYNAME_R
        struct hostent hp_allocated;
#ifdef HAVE_GETHOSTBYNAME_R_3_ARG
        struct hostent_data data;
#else
        char buf[16384];
        int buf_len = (sizeof buf) - 1;
        int errnop;
#endif
#if defined(HAVE_GETHOSTBYNAME_R_3_ARG) || defined(HAVE_GETHOSTBYNAME_R_6_ARG)
        int result;
#endif
#endif /* HAVE_GETHOSTBYNAME_R */
        char *ap;
        int al;
        int af;

        if (!PyArg_ParseTuple(args, "s:gethostbyaddr", &ip_num))
                return NULL;
        af = AF_UNSPEC;
        if (setipaddr(ip_num, sa, sizeof(addr), af) < 0)
                return NULL;
        af = sa->sa_family;
        ap = NULL;
        al = 0;
        switch (af) {
        case AF_INET:
                ap = (char *)&((struct sockaddr_in *)sa)->sin_addr;
                al = sizeof(((struct sockaddr_in *)sa)->sin_addr);
                break;
#ifdef ENABLE_IPV6
        case AF_INET6:
                ap = (char *)&((struct sockaddr_in6 *)sa)->sin6_addr;
                al = sizeof(((struct sockaddr_in6 *)sa)->sin6_addr);
                break;
#endif
        default:
                PyErr_SetString(socket_error, "unsupported address family");
                return NULL;
        }
        Py_BEGIN_ALLOW_THREADS
#ifdef HAVE_GETHOSTBYNAME_R
#if   defined(HAVE_GETHOSTBYNAME_R_6_ARG)
        result = gethostbyaddr_r(ap, al, af,
                &hp_allocated, buf, buf_len,
                &h, &errnop);
#elif defined(HAVE_GETHOSTBYNAME_R_5_ARG)
        h = gethostbyaddr_r(ap, al, af,
                            &hp_allocated, buf, buf_len, &errnop);
#else /* HAVE_GETHOSTBYNAME_R_3_ARG */
        memset((void *) &data, '\0', sizeof(data));
        result = gethostbyaddr_r(ap, al, af, &hp_allocated, &data);
        h = (result != 0) ? NULL : &hp_allocated;
#endif
#else /* not HAVE_GETHOSTBYNAME_R */
#ifdef USE_GETHOSTBYNAME_LOCK
        PyThread_acquire_lock(netdb_lock, 1);
#endif
        h = gethostbyaddr(ap, al, af);
#endif /* HAVE_GETHOSTBYNAME_R */
        Py_END_ALLOW_THREADS
        ret = gethost_common(h, (struct sockaddr *)&addr, sizeof(addr), af);
#ifdef USE_GETHOSTBYNAME_LOCK
        PyThread_release_lock(netdb_lock);
#endif
        return ret;
}

PyDoc_STRVAR(gethostbyaddr_doc,
"gethostbyaddr(host) -> (name, aliaslist, addresslist)\n\
\n\
Return the true host name, a list of aliases, and a list of IP addresses,\n\
for a host.  The host argument is a string giving a host name or IP number.");


/* Python interface to getservbyname(name).
   This only returns the port number, since the other info is already
   known or not useful (like the list of aliases). */

/*ARGSUSED*/
static PyObject *
socket_getservbyname(PyObject *self, PyObject *args)
{
        char *name, *proto=NULL;
        struct servent *sp;
        if (!PyArg_ParseTuple(args, "s|s:getservbyname", &name, &proto))
                return NULL;
        Py_BEGIN_ALLOW_THREADS
        sp = getservbyname(name, proto);
        Py_END_ALLOW_THREADS
        if (sp == NULL) {
                PyErr_SetString(socket_error, "service/proto not found");
                return NULL;
        }
        return PyInt_FromLong((long) ntohs(sp->s_port));
}

PyDoc_STRVAR(getservbyname_doc,
"getservbyname(servicename[, protocolname]) -> integer\n\
\n\
Return a port number from a service name and protocol name.\n\
The optional protocol name, if given, should be 'tcp' or 'udp',\n\
otherwise any protocol will match.");


/* Python interface to getservbyport(port).
   This only returns the service name, since the other info is already
   known or not useful (like the list of aliases). */

/*ARGSUSED*/
static PyObject *
socket_getservbyport(PyObject *self, PyObject *args)
{
        unsigned short port;
        char *proto=NULL;
        struct servent *sp;
        if (!PyArg_ParseTuple(args, "H|s:getservbyport", &port, &proto))
                return NULL;
        Py_BEGIN_ALLOW_THREADS
        sp = getservbyport(htons(port), proto);
        Py_END_ALLOW_THREADS
        if (sp == NULL) {
                PyErr_SetString(socket_error, "port/proto not found");
                return NULL;
        }
        return PyString_FromString(sp->s_name);
}

PyDoc_STRVAR(getservbyport_doc,
"getservbyport(port[, protocolname]) -> string\n\
\n\
Return the service name from a port number and protocol name.\n\
The optional protocol name, if given, should be 'tcp' or 'udp',\n\
otherwise any protocol will match.");

/* Python interface to getprotobyname(name).
   This only returns the protocol number, since the other info is
   already known or not useful (like the list of aliases). */

/*ARGSUSED*/
static PyObject *
socket_getprotobyname(PyObject *self, PyObject *args)
{
        char *name;
        struct protoent *sp;
#ifdef __BEOS__
/* Not available in BeOS yet. - [cjh] */
        PyErr_SetString(socket_error, "getprotobyname not supported");
        return NULL;
#else
        if (!PyArg_ParseTuple(args, "s:getprotobyname", &name))
                return NULL;
        Py_BEGIN_ALLOW_THREADS
        sp = getprotobyname(name);
        Py_END_ALLOW_THREADS
        if (sp == NULL) {
                PyErr_SetString(socket_error, "protocol not found");
                return NULL;
        }
        return PyInt_FromLong((long) sp->p_proto);
#endif
}

PyDoc_STRVAR(getprotobyname_doc,
"getprotobyname(name) -> integer\n\
\n\
Return the protocol number for the named protocol.  (Rarely used.)");


#ifdef HAVE_SOCKETPAIR
/* Create a pair of sockets using the socketpair() function.
   Arguments as for socket() except the default family is AF_UNIX if
   defined on the platform; otherwise, the default is AF_INET. */

/*ARGSUSED*/
static PyObject *
socket_socketpair(PyObject *self, PyObject *args)
{
        PySocketSockObject *s0 = NULL, *s1 = NULL;
        SOCKET_T sv[2];
        int family, type = SOCK_STREAM, proto = 0;
        PyObject *res = NULL;

#if defined(AF_UNIX)
        family = AF_UNIX;
#else
        family = AF_INET;
#endif
        if (!PyArg_ParseTuple(args, "|iii:socketpair",
                              &family, &type, &proto))
                return NULL;
        /* Create a pair of socket fds */
        if (socketpair(family, type, proto, sv) < 0)
                return set_error();
        s0 = new_sockobject(sv[0], family, type, proto);
        if (s0 == NULL)
                goto finally;
        s1 = new_sockobject(sv[1], family, type, proto);
        if (s1 == NULL)
                goto finally;
        res = PyTuple_Pack(2, s0, s1);

finally:
        if (res == NULL) {
                if (s0 == NULL)
                        SOCKETCLOSE(sv[0]);
                if (s1 == NULL)
                        SOCKETCLOSE(sv[1]);
        }
        Py_XDECREF(s0);
        Py_XDECREF(s1);
        return res;
}

PyDoc_STRVAR(socketpair_doc,
"socketpair([family[, type[, proto]]]) -> (socket object, socket object)\n\
\n\
Create a pair of socket objects from the sockets returned by the platform\n\
socketpair() function.\n\
The arguments are the same as for socket() except the default family is\n\
AF_UNIX if defined on the platform; otherwise, the default is AF_INET.");

#endif /* HAVE_SOCKETPAIR */


#ifndef NO_DUP
/* Create a socket object from a numeric file description.
   Useful e.g. if stdin is a socket.
   Additional arguments as for socket(). */

/*ARGSUSED*/
static PyObject *
socket_fromfd(PyObject *self, PyObject *args)
{
        PySocketSockObject *s;
        SOCKET_T fd;
        int family, type, proto = 0;
        if (!PyArg_ParseTuple(args, "iii|i:fromfd",
                              &fd, &family, &type, &proto))
                return NULL;
        /* Dup the fd so it and the socket can be closed independently */
        fd = dup(fd);
        if (fd < 0)
                return set_error();
        s = new_sockobject(fd, family, type, proto);
        return (PyObject *) s;
}

PyDoc_STRVAR(fromfd_doc,
"fromfd(fd, family, type[, proto]) -> socket object\n\
\n\
Create a socket object from a duplicate of the given\n\
file descriptor.\n\
The remaining arguments are the same as for socket().");

#endif /* NO_DUP */


static PyObject *
socket_ntohs(PyObject *self, PyObject *args)
{
        int x1, x2;

        if (!PyArg_ParseTuple(args, "i:ntohs", &x1)) {
                return NULL;
        }
        if (x1 < 0) {
                PyErr_SetString(PyExc_OverflowError,
                        "can't convert negative number to unsigned long");
                return NULL;
        }
        x2 = (unsigned int)ntohs((unsigned short)x1);
        return PyInt_FromLong(x2);
}

PyDoc_STRVAR(ntohs_doc,
"ntohs(integer) -> integer\n\
\n\
Convert a 16-bit integer from network to host byte order.");


static PyObject *
socket_ntohl(PyObject *self, PyObject *arg)
{
        unsigned long x;

        if (PyInt_Check(arg)) {
                x = PyInt_AS_LONG(arg);
                if (x == (unsigned long) -1 && PyErr_Occurred())
                        return NULL;
                if ((long)x < 0) {
                        PyErr_SetString(PyExc_OverflowError,
                          "can't convert negative number to unsigned long");
                        return NULL;
                }
        }
        else if (PyLong_Check(arg)) {
                x = PyLong_AsUnsignedLong(arg);
                if (x == (unsigned long) -1 && PyErr_Occurred())
                        return NULL;
#if SIZEOF_LONG > 4
                {
                        unsigned long y;
                        /* only want the trailing 32 bits */
                        y = x & 0xFFFFFFFFUL;
                        if (y ^ x)
                                return PyErr_Format(PyExc_OverflowError,
                                            "long int larger than 32 bits");
                        x = y;
                }
#endif
        }
        else
                return PyErr_Format(PyExc_TypeError,
                                    "expected int/long, %s found",
                                    Py_Type(arg)->tp_name);
        if (x == (unsigned long) -1 && PyErr_Occurred())
                return NULL;
        return PyLong_FromUnsignedLong(ntohl(x));
}

PyDoc_STRVAR(ntohl_doc,
"ntohl(integer) -> integer\n\
\n\
Convert a 32-bit integer from network to host byte order.");


static PyObject *
socket_htons(PyObject *self, PyObject *args)
{
        int x1, x2;

        if (!PyArg_ParseTuple(args, "i:htons", &x1)) {
                return NULL;
        }
        if (x1 < 0) {
                PyErr_SetString(PyExc_OverflowError,
                        "can't convert negative number to unsigned long");
                return NULL;
        }
        x2 = (unsigned int)htons((unsigned short)x1);
        return PyInt_FromLong(x2);
}

PyDoc_STRVAR(htons_doc,
"htons(integer) -> integer\n\
\n\
Convert a 16-bit integer from host to network byte order.");


static PyObject *
socket_htonl(PyObject *self, PyObject *arg)
{
        unsigned long x;

        if (PyInt_Check(arg)) {
                x = PyInt_AS_LONG(arg);
                if (x == (unsigned long) -1 && PyErr_Occurred())
                        return NULL;
                if ((long)x < 0) {
                        PyErr_SetString(PyExc_OverflowError,
                          "can't convert negative number to unsigned long");
                        return NULL;
                }
        }
        else if (PyLong_Check(arg)) {
                x = PyLong_AsUnsignedLong(arg);
                if (x == (unsigned long) -1 && PyErr_Occurred())
                        return NULL;
#if SIZEOF_LONG > 4
                {
                        unsigned long y;
                        /* only want the trailing 32 bits */
                        y = x & 0xFFFFFFFFUL;
                        if (y ^ x)
                                return PyErr_Format(PyExc_OverflowError,
                                            "long int larger than 32 bits");
                        x = y;
                }
#endif
        }
        else
                return PyErr_Format(PyExc_TypeError,
                                    "expected int/long, %s found",
                                    Py_Type(arg)->tp_name);
        return PyLong_FromUnsignedLong(htonl((unsigned long)x));
}

PyDoc_STRVAR(htonl_doc,
"htonl(integer) -> integer\n\
\n\
Convert a 32-bit integer from host to network byte order.");

/* socket.inet_aton() and socket.inet_ntoa() functions. */

PyDoc_STRVAR(inet_aton_doc,
"inet_aton(string) -> packed 32-bit IP representation\n\
\n\
Convert an IP address in string format (123.45.67.89) to the 32-bit packed\n\
binary format used in low-level network functions.");

static PyObject*
socket_inet_aton(PyObject *self, PyObject *args)
{
#ifndef INADDR_NONE
#define INADDR_NONE (-1)
#endif
#ifdef HAVE_INET_ATON
        struct in_addr buf;
#endif

#if !defined(HAVE_INET_ATON) || defined(USE_INET_ATON_WEAKLINK)
        /* Have to use inet_addr() instead */
        unsigned long packed_addr;
#endif
        char *ip_addr;

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


#ifdef HAVE_INET_ATON

#ifdef USE_INET_ATON_WEAKLINK
    if (inet_aton != NULL) {
#endif
        if (inet_aton(ip_addr, &buf))
                return PyString_FromStringAndSize((char *)(&buf),
                                                  sizeof(buf));

        PyErr_SetString(socket_error,
                        "illegal IP address string passed to inet_aton");
        return NULL;

#ifdef USE_INET_ATON_WEAKLINK
   } else {
#endif

#endif

#if !defined(HAVE_INET_ATON) || defined(USE_INET_ATON_WEAKLINK)

        /* special-case this address as inet_addr might return INADDR_NONE
         * for this */
        if (strcmp(ip_addr, "255.255.255.255") == 0) {
                packed_addr = 0xFFFFFFFF;
        } else {

                packed_addr = inet_addr(ip_addr);

                if (packed_addr == INADDR_NONE) {       /* invalid address */
                        PyErr_SetString(socket_error,
                                "illegal IP address string passed to inet_aton");
                        return NULL;
                }
        }
        return PyString_FromStringAndSize((char *) &packed_addr,
                                          sizeof(packed_addr));

#ifdef USE_INET_ATON_WEAKLINK
   }
#endif

#endif
}

PyDoc_STRVAR(inet_ntoa_doc,
"inet_ntoa(packed_ip) -> ip_address_string\n\
\n\
Convert an IP address from 32-bit packed binary format to string format");

static PyObject*
socket_inet_ntoa(PyObject *self, PyObject *args)
{
        char *packed_str;
        int addr_len;
        struct in_addr packed_addr;

        if (!PyArg_ParseTuple(args, "s#:inet_ntoa", &packed_str, &addr_len)) {
                return NULL;
        }

        if (addr_len != sizeof(packed_addr)) {
                PyErr_SetString(socket_error,
                        "packed IP wrong length for inet_ntoa");
                return NULL;
        }

        memcpy(&packed_addr, packed_str, addr_len);

        return PyString_FromString(inet_ntoa(packed_addr));
}

#ifdef HAVE_INET_PTON

PyDoc_STRVAR(inet_pton_doc,
"inet_pton(af, ip) -> packed IP address string\n\
\n\
Convert an IP address from string format to a packed string suitable\n\
for use with low-level network functions.");

static PyObject *
socket_inet_pton(PyObject *self, PyObject *args)
{
        int af;
        char* ip;
        int retval;
#ifdef ENABLE_IPV6
        char packed[MAX(sizeof(struct in_addr), sizeof(struct in6_addr))];
#else
        char packed[sizeof(struct in_addr)];
#endif
        if (!PyArg_ParseTuple(args, "is:inet_pton", &af, &ip)) {
                return NULL;
        }

#if !defined(ENABLE_IPV6) && defined(AF_INET6)
        if(af == AF_INET6) {
                PyErr_SetString(socket_error,
                                "can't use AF_INET6, IPv6 is disabled");
                return NULL;
        }
#endif

        retval = inet_pton(af, ip, packed);
        if (retval < 0) {
                PyErr_SetFromErrno(socket_error);
                return NULL;
        } else if (retval == 0) {
                PyErr_SetString(socket_error,
                        "illegal IP address string passed to inet_pton");
                return NULL;
        } else if (af == AF_INET) {
                return PyString_FromStringAndSize(packed,
                        sizeof(struct in_addr));
#ifdef ENABLE_IPV6
        } else if (af == AF_INET6) {
                return PyString_FromStringAndSize(packed,
                        sizeof(struct in6_addr));
#endif
        } else {
                PyErr_SetString(socket_error, "unknown address family");
                return NULL;
        }
}

PyDoc_STRVAR(inet_ntop_doc,
"inet_ntop(af, packed_ip) -> string formatted IP address\n\
\n\
Convert a packed IP address of the given family to string format.");

static PyObject *
socket_inet_ntop(PyObject *self, PyObject *args)
{
        int af;
        char* packed;
        int len;
        const char* retval;
#ifdef ENABLE_IPV6
        char ip[MAX(INET_ADDRSTRLEN, INET6_ADDRSTRLEN) + 1];
#else
        char ip[INET_ADDRSTRLEN + 1];
#endif

        /* Guarantee NUL-termination for PyString_FromString() below */
        memset((void *) &ip[0], '\0', sizeof(ip));

        if (!PyArg_ParseTuple(args, "is#:inet_ntop", &af, &packed, &len)) {
                return NULL;
        }

        if (af == AF_INET) {
                if (len != sizeof(struct in_addr)) {
                        PyErr_SetString(PyExc_ValueError,
                                "invalid length of packed IP address string");
                        return NULL;
                }
#ifdef ENABLE_IPV6
        } else if (af == AF_INET6) {
                if (len != sizeof(struct in6_addr)) {
                        PyErr_SetString(PyExc_ValueError,
                                "invalid length of packed IP address string");
                        return NULL;
                }
#endif
        } else {
                PyErr_Format(PyExc_ValueError,
                        "unknown address family %d", af);
                return NULL;
        }

        retval = inet_ntop(af, packed, ip, sizeof(ip));
        if (!retval) {
                PyErr_SetFromErrno(socket_error);
                return NULL;
        } else {
                return PyString_FromString(retval);
        }

        /* NOTREACHED */
        PyErr_SetString(PyExc_RuntimeError, "invalid handling of inet_ntop");
        return NULL;
}

#endif /* HAVE_INET_PTON */

/* Python interface to getaddrinfo(host, port). */

/*ARGSUSED*/
static PyObject *
socket_getaddrinfo(PyObject *self, PyObject *args)
{
        struct addrinfo hints, *res;
        struct addrinfo *res0 = NULL;
        PyObject *hobj = NULL;
        PyObject *pobj = (PyObject *)NULL;
        char pbuf[30];
        char *hptr, *pptr;
        int family, socktype, protocol, flags;
        int error;
        PyObject *all = (PyObject *)NULL;
        PyObject *single = (PyObject *)NULL;
        PyObject *idna = NULL;

        family = socktype = protocol = flags = 0;
        family = AF_UNSPEC;
        if (!PyArg_ParseTuple(args, "OO|iiii:getaddrinfo",
                              &hobj, &pobj, &family, &socktype,
                              &protocol, &flags)) {
                return NULL;
        }
        if (hobj == Py_None) {
                hptr = NULL;
        } else if (PyUnicode_Check(hobj)) {
                idna = PyObject_CallMethod(hobj, "encode", "s", "idna");
                if (!idna)
                        return NULL;
                hptr = PyString_AsString(idna);
        } else if (PyString_Check(hobj)) {
                hptr = PyString_AsString(hobj);
        } else {
                PyErr_SetString(PyExc_TypeError,
                                "getaddrinfo() argument 1 must be string or None");
                return NULL;
        }
        if (PyInt_Check(pobj)) {
                PyOS_snprintf(pbuf, sizeof(pbuf), "%ld", PyInt_AsLong(pobj));
                pptr = pbuf;
        } else if (PyString_Check(pobj)) {
                pptr = PyString_AsString(pobj);
        } else if (pobj == Py_None) {
                pptr = (char *)NULL;
        } else {
                PyErr_SetString(socket_error, "Int or String expected");
                goto err;
        }
        memset(&hints, 0, sizeof(hints));
        hints.ai_family = family;
        hints.ai_socktype = socktype;
        hints.ai_protocol = protocol;
        hints.ai_flags = flags;
        Py_BEGIN_ALLOW_THREADS
        ACQUIRE_GETADDRINFO_LOCK
        error = getaddrinfo(hptr, pptr, &hints, &res0);
        Py_END_ALLOW_THREADS
        RELEASE_GETADDRINFO_LOCK  /* see comment in setipaddr() */
        if (error) {
                set_gaierror(error);
                goto err;
        }

        if ((all = PyList_New(0)) == NULL)
                goto err;
        for (res = res0; res; res = res->ai_next) {
                PyObject *addr =
                        makesockaddr(-1, res->ai_addr, res->ai_addrlen, protocol);
                if (addr == NULL)
                        goto err;
                single = Py_BuildValue("iiisO", res->ai_family,
                        res->ai_socktype, res->ai_protocol,
                        res->ai_canonname ? res->ai_canonname : "",
                        addr);
                Py_DECREF(addr);
                if (single == NULL)
                        goto err;

                if (PyList_Append(all, single))
                        goto err;
                Py_XDECREF(single);
        }
        Py_XDECREF(idna);
        if (res0)
                freeaddrinfo(res0);
        return all;
 err:
        Py_XDECREF(single);
        Py_XDECREF(all);
        Py_XDECREF(idna);
        if (res0)
                freeaddrinfo(res0);
        return (PyObject *)NULL;
}

PyDoc_STRVAR(getaddrinfo_doc,
"getaddrinfo(host, port [, family, socktype, proto, flags])\n\
    -> list of (family, socktype, proto, canonname, sockaddr)\n\
\n\
Resolve host and port into addrinfo struct.");

/* Python interface to getnameinfo(sa, flags). */

/*ARGSUSED*/
static PyObject *
socket_getnameinfo(PyObject *self, PyObject *args)
{
        PyObject *sa = (PyObject *)NULL;
        int flags;
        char *hostp;
        int port, flowinfo, scope_id;
        char hbuf[NI_MAXHOST], pbuf[NI_MAXSERV];
        struct addrinfo hints, *res = NULL;
        int error;
        PyObject *ret = (PyObject *)NULL;

        flags = flowinfo = scope_id = 0;
        if (!PyArg_ParseTuple(args, "Oi:getnameinfo", &sa, &flags))
                return NULL;
        if  (!PyArg_ParseTuple(sa, "si|ii",
                               &hostp, &port, &flowinfo, &scope_id))
                return NULL;
        PyOS_snprintf(pbuf, sizeof(pbuf), "%d", port);
        memset(&hints, 0, sizeof(hints));
        hints.ai_family = AF_UNSPEC;
        hints.ai_socktype = SOCK_DGRAM; /* make numeric port happy */
        Py_BEGIN_ALLOW_THREADS
        ACQUIRE_GETADDRINFO_LOCK
        error = getaddrinfo(hostp, pbuf, &hints, &res);
        Py_END_ALLOW_THREADS
        RELEASE_GETADDRINFO_LOCK  /* see comment in setipaddr() */
        if (error) {
                set_gaierror(error);
                goto fail;
        }
        if (res->ai_next) {
                PyErr_SetString(socket_error,
                        "sockaddr resolved to multiple addresses");
                goto fail;
        }
        switch (res->ai_family) {
        case AF_INET:
            {
                char *t1;
                int t2;
                if (PyArg_ParseTuple(sa, "si", &t1, &t2) == 0) {
                        PyErr_SetString(socket_error,
                                "IPv4 sockaddr must be 2 tuple");
                        goto fail;
                }
                break;
            }
#ifdef ENABLE_IPV6
        case AF_INET6:
            {
                struct sockaddr_in6 *sin6;
                sin6 = (struct sockaddr_in6 *)res->ai_addr;
                sin6->sin6_flowinfo = flowinfo;
                sin6->sin6_scope_id = scope_id;
                break;
            }
#endif
        }
        error = getnameinfo(res->ai_addr, res->ai_addrlen,
                        hbuf, sizeof(hbuf), pbuf, sizeof(pbuf), flags);
        if (error) {
                set_gaierror(error);
                goto fail;
        }
        ret = Py_BuildValue("ss", hbuf, pbuf);

fail:
        if (res)
                freeaddrinfo(res);
        return ret;
}

PyDoc_STRVAR(getnameinfo_doc,
"getnameinfo(sockaddr, flags) --> (host, port)\n\
\n\
Get host and port for a sockaddr.");


/* Python API to getting and setting the default timeout value. */

static PyObject *
socket_getdefaulttimeout(PyObject *self)
{
        if (defaulttimeout < 0.0) {
                Py_INCREF(Py_None);
                return Py_None;
        }
        else
                return PyFloat_FromDouble(defaulttimeout);
}

PyDoc_STRVAR(getdefaulttimeout_doc,
"getdefaulttimeout() -> timeout\n\
\n\
Returns the default timeout in floating seconds for new socket objects.\n\
A value of None indicates that new socket objects have no timeout.\n\
When the socket module is first imported, the default is None.");

static PyObject *
socket_setdefaulttimeout(PyObject *self, PyObject *arg)
{
        double timeout;

        if (arg == Py_None)
                timeout = -1.0;
        else {
                timeout = PyFloat_AsDouble(arg);
                if (timeout < 0.0) {
                        if (!PyErr_Occurred())
                                PyErr_SetString(PyExc_ValueError,
                                                "Timeout value out of range");
                        return NULL;
                }
        }

        defaulttimeout = timeout;

        Py_INCREF(Py_None);
        return Py_None;
}

PyDoc_STRVAR(setdefaulttimeout_doc,
"setdefaulttimeout(timeout)\n\
\n\
Set the default timeout in floating seconds for new socket objects.\n\
A value of None indicates that new socket objects have no timeout.\n\
When the socket module is first imported, the default is None.");


/* List of functions exported by this module. */

static PyMethodDef socket_methods[] = {
        {"gethostbyname",       socket_gethostbyname,
         METH_VARARGS, gethostbyname_doc},
        {"gethostbyname_ex",    socket_gethostbyname_ex,
         METH_VARARGS, ghbn_ex_doc},
        {"gethostbyaddr",       socket_gethostbyaddr,
         METH_VARARGS, gethostbyaddr_doc},
        {"gethostname",         socket_gethostname,
         METH_NOARGS,  gethostname_doc},
        {"getservbyname",       socket_getservbyname,
         METH_VARARGS, getservbyname_doc},
        {"getservbyport",       socket_getservbyport,
         METH_VARARGS, getservbyport_doc},
        {"getprotobyname",      socket_getprotobyname,
         METH_VARARGS, getprotobyname_doc},
#ifndef NO_DUP
        {"fromfd",              socket_fromfd,
         METH_VARARGS, fromfd_doc},
#endif
#ifdef HAVE_SOCKETPAIR
        {"socketpair",          socket_socketpair,
         METH_VARARGS, socketpair_doc},
#endif
        {"ntohs",               socket_ntohs,
         METH_VARARGS, ntohs_doc},
        {"ntohl",               socket_ntohl,
         METH_O, ntohl_doc},
        {"htons",               socket_htons,
         METH_VARARGS, htons_doc},
        {"htonl",               socket_htonl,
         METH_O, htonl_doc},
        {"inet_aton",           socket_inet_aton,
         METH_VARARGS, inet_aton_doc},
        {"inet_ntoa",           socket_inet_ntoa,
         METH_VARARGS, inet_ntoa_doc},
#ifdef HAVE_INET_PTON
        {"inet_pton",           socket_inet_pton,
         METH_VARARGS, inet_pton_doc},
        {"inet_ntop",           socket_inet_ntop,
         METH_VARARGS, inet_ntop_doc},
#endif
        {"getaddrinfo",         socket_getaddrinfo,
         METH_VARARGS, getaddrinfo_doc},
        {"getnameinfo",         socket_getnameinfo,
         METH_VARARGS, getnameinfo_doc},
        {"getdefaulttimeout",   (PyCFunction)socket_getdefaulttimeout,
         METH_NOARGS, getdefaulttimeout_doc},
        {"setdefaulttimeout",   socket_setdefaulttimeout,
         METH_O, setdefaulttimeout_doc},
        {NULL,                  NULL}            /* Sentinel */
};


#ifdef RISCOS
#define OS_INIT_DEFINED

static int
os_init(void)
{
        _kernel_swi_regs r;

        r.r[0] = 0;
        _kernel_swi(0x43380, &r, &r);
        taskwindow = r.r[0];

        return 1;
}

#endif /* RISCOS */


#ifdef MS_WINDOWS
#define OS_INIT_DEFINED

/* Additional initialization and cleanup for Windows */

static void
os_cleanup(void)
{
        WSACleanup();
}

static int
os_init(void)
{
        WSADATA WSAData;
        int ret;
        char buf[100];
        ret = WSAStartup(0x0101, &WSAData);
        switch (ret) {
        case 0: /* No error */
                Py_AtExit(os_cleanup);
                return 1; /* Success */
        case WSASYSNOTREADY:
                PyErr_SetString(PyExc_ImportError,
                                "WSAStartup failed: network not ready");
                break;
        case WSAVERNOTSUPPORTED:
        case WSAEINVAL:
                PyErr_SetString(
                        PyExc_ImportError,
                        "WSAStartup failed: requested version not supported");
                break;
        default:
                PyOS_snprintf(buf, sizeof(buf),
                              "WSAStartup failed: error code %d", ret);
                PyErr_SetString(PyExc_ImportError, buf);
                break;
        }
        return 0; /* Failure */
}

#endif /* MS_WINDOWS */


#ifdef PYOS_OS2
#define OS_INIT_DEFINED

/* Additional initialization for OS/2 */

static int
os_init(void)
{
#ifndef PYCC_GCC
        char reason[64];
        int rc = sock_init();

        if (rc == 0) {
                return 1; /* Success */
        }

        PyOS_snprintf(reason, sizeof(reason),
                      "OS/2 TCP/IP Error# %d", sock_errno());
        PyErr_SetString(PyExc_ImportError, reason);

        return 0;  /* Failure */
#else
        /* No need to initialise sockets with GCC/EMX */
        return 1; /* Success */
#endif
}

#endif /* PYOS_OS2 */


#ifndef OS_INIT_DEFINED
static int
os_init(void)
{
        return 1; /* Success */
}
#endif


/* C API table - always add new things to the end for binary
   compatibility. */
static
PySocketModule_APIObject PySocketModuleAPI =
{
        &sock_type,
        NULL
};


/* Initialize the _socket module.

   This module is actually called "_socket", and there's a wrapper
   "socket.py" which implements some additional functionality.  On some
   platforms (e.g. Windows and OS/2), socket.py also implements a
   wrapper for the socket type that provides missing functionality such
   as makefile(), dup() and fromfd().  The import of "_socket" may fail
   with an ImportError exception if os-specific initialization fails.
   On Windows, this does WINSOCK initialization.  When WINSOCK is
   initialized succesfully, a call to WSACleanup() is scheduled to be
   made at exit time.
*/

PyDoc_STRVAR(socket_doc,
"Implementation module for socket operations.\n\
\n\
See the socket module for documentation.");

PyMODINIT_FUNC
init_socket(void)
{
        PyObject *m, *has_ipv6;

        if (!os_init())
                return;

        Py_Type(&sock_type) = &PyType_Type;
        m = Py_InitModule3(PySocket_MODULE_NAME,
                           socket_methods,
                           socket_doc);
        if (m == NULL)
                return;

        socket_error = PyErr_NewException("socket.error", NULL, NULL);
        if (socket_error == NULL)
                return;
        PySocketModuleAPI.error = socket_error;
        Py_INCREF(socket_error);
        PyModule_AddObject(m, "error", socket_error);
        socket_herror = PyErr_NewException("socket.herror",
                                           socket_error, NULL);
        if (socket_herror == NULL)
                return;
        Py_INCREF(socket_herror);
        PyModule_AddObject(m, "herror", socket_herror);
        socket_gaierror = PyErr_NewException("socket.gaierror", socket_error,
            NULL);
        if (socket_gaierror == NULL)
                return;
        Py_INCREF(socket_gaierror);
        PyModule_AddObject(m, "gaierror", socket_gaierror);
        socket_timeout = PyErr_NewException("socket.timeout",
                                            socket_error, NULL);
        if (socket_timeout == NULL)
                return;
        Py_INCREF(socket_timeout);
        PyModule_AddObject(m, "timeout", socket_timeout);
        Py_INCREF((PyObject *)&sock_type);
        if (PyModule_AddObject(m, "SocketType",
                               (PyObject *)&sock_type) != 0)
                return;
        Py_INCREF((PyObject *)&sock_type);
        if (PyModule_AddObject(m, "socket",
                               (PyObject *)&sock_type) != 0)
                return;

#ifdef ENABLE_IPV6
        has_ipv6 = Py_True;
#else
        has_ipv6 = Py_False;
#endif
        Py_INCREF(has_ipv6);
        PyModule_AddObject(m, "has_ipv6", has_ipv6);

        /* Export C API */
        if (PyModule_AddObject(m, PySocket_CAPI_NAME,
               PyCObject_FromVoidPtr((void *)&PySocketModuleAPI, NULL)
                                 ) != 0)
                return;

        /* Address families (we only support AF_INET and AF_UNIX) */
#ifdef AF_UNSPEC
        PyModule_AddIntConstant(m, "AF_UNSPEC", AF_UNSPEC);
#endif
        PyModule_AddIntConstant(m, "AF_INET", AF_INET);
#ifdef AF_INET6
        PyModule_AddIntConstant(m, "AF_INET6", AF_INET6);
#endif /* AF_INET6 */
#if defined(AF_UNIX)
        PyModule_AddIntConstant(m, "AF_UNIX", AF_UNIX);
#endif /* AF_UNIX */
#ifdef AF_AX25
        /* Amateur Radio AX.25 */
        PyModule_AddIntConstant(m, "AF_AX25", AF_AX25);
#endif
#ifdef AF_IPX
        PyModule_AddIntConstant(m, "AF_IPX", AF_IPX); /* Novell IPX */
#endif
#ifdef AF_APPLETALK
        /* Appletalk DDP */
        PyModule_AddIntConstant(m, "AF_APPLETALK", AF_APPLETALK);
#endif
#ifdef AF_NETROM
        /* Amateur radio NetROM */
        PyModule_AddIntConstant(m, "AF_NETROM", AF_NETROM);
#endif
#ifdef AF_BRIDGE
        /* Multiprotocol bridge */
        PyModule_AddIntConstant(m, "AF_BRIDGE", AF_BRIDGE);
#endif
#ifdef AF_ATMPVC
        /* ATM PVCs */
        PyModule_AddIntConstant(m, "AF_ATMPVC", AF_ATMPVC);
#endif
#ifdef AF_AAL5
        /* Reserved for Werner's ATM */
        PyModule_AddIntConstant(m, "AF_AAL5", AF_AAL5);
#endif
#ifdef AF_X25
        /* Reserved for X.25 project */
        PyModule_AddIntConstant(m, "AF_X25", AF_X25);
#endif
#ifdef AF_INET6
        PyModule_AddIntConstant(m, "AF_INET6", AF_INET6); /* IP version 6 */
#endif
#ifdef AF_ROSE
        /* Amateur Radio X.25 PLP */
        PyModule_AddIntConstant(m, "AF_ROSE", AF_ROSE);
#endif
#ifdef AF_DECnet
        /* Reserved for DECnet project */
        PyModule_AddIntConstant(m, "AF_DECnet", AF_DECnet);
#endif
#ifdef AF_NETBEUI
        /* Reserved for 802.2LLC project */
        PyModule_AddIntConstant(m, "AF_NETBEUI", AF_NETBEUI);
#endif
#ifdef AF_SECURITY
        /* Security callback pseudo AF */
        PyModule_AddIntConstant(m, "AF_SECURITY", AF_SECURITY);
#endif
#ifdef AF_KEY
        /* PF_KEY key management API */
        PyModule_AddIntConstant(m, "AF_KEY", AF_KEY);
#endif
#ifdef AF_NETLINK
        /*  */
        PyModule_AddIntConstant(m, "AF_NETLINK", AF_NETLINK);
        PyModule_AddIntConstant(m, "NETLINK_ROUTE", NETLINK_ROUTE);
#ifdef NETLINK_SKIP
        PyModule_AddIntConstant(m, "NETLINK_SKIP", NETLINK_SKIP);
#endif
#ifdef NETLINK_W1
        PyModule_AddIntConstant(m, "NETLINK_W1", NETLINK_W1);
#endif
        PyModule_AddIntConstant(m, "NETLINK_USERSOCK", NETLINK_USERSOCK);
        PyModule_AddIntConstant(m, "NETLINK_FIREWALL", NETLINK_FIREWALL);
#ifdef NETLINK_TCPDIAG
        PyModule_AddIntConstant(m, "NETLINK_TCPDIAG", NETLINK_TCPDIAG);
#endif
#ifdef NETLINK_NFLOG
        PyModule_AddIntConstant(m, "NETLINK_NFLOG", NETLINK_NFLOG);
#endif
#ifdef NETLINK_XFRM
        PyModule_AddIntConstant(m, "NETLINK_XFRM", NETLINK_XFRM);
#endif
#ifdef NETLINK_ARPD
        PyModule_AddIntConstant(m, "NETLINK_ARPD", NETLINK_ARPD);
#endif
#ifdef NETLINK_ROUTE6
        PyModule_AddIntConstant(m, "NETLINK_ROUTE6", NETLINK_ROUTE6);
#endif
        PyModule_AddIntConstant(m, "NETLINK_IP6_FW", NETLINK_IP6_FW);
#ifdef NETLINK_DNRTMSG
        PyModule_AddIntConstant(m, "NETLINK_DNRTMSG", NETLINK_DNRTMSG);
#endif 
#ifdef NETLINK_TAPBASE
        PyModule_AddIntConstant(m, "NETLINK_TAPBASE", NETLINK_TAPBASE);
#endif
#endif /* AF_NETLINK */
#ifdef AF_ROUTE
        /* Alias to emulate 4.4BSD */
        PyModule_AddIntConstant(m, "AF_ROUTE", AF_ROUTE);
#endif
#ifdef AF_ASH
        /* Ash */
        PyModule_AddIntConstant(m, "AF_ASH", AF_ASH);
#endif
#ifdef AF_ECONET
        /* Acorn Econet */
        PyModule_AddIntConstant(m, "AF_ECONET", AF_ECONET);
#endif
#ifdef AF_ATMSVC
        /* ATM SVCs */
        PyModule_AddIntConstant(m, "AF_ATMSVC", AF_ATMSVC);
#endif
#ifdef AF_SNA
        /* Linux SNA Project (nutters!) */
        PyModule_AddIntConstant(m, "AF_SNA", AF_SNA);
#endif
#ifdef AF_IRDA
        /* IRDA sockets */
        PyModule_AddIntConstant(m, "AF_IRDA", AF_IRDA);
#endif
#ifdef AF_PPPOX
        /* PPPoX sockets */
        PyModule_AddIntConstant(m, "AF_PPPOX", AF_PPPOX);
#endif
#ifdef AF_WANPIPE
        /* Wanpipe API Sockets */
        PyModule_AddIntConstant(m, "AF_WANPIPE", AF_WANPIPE);
#endif
#ifdef AF_LLC
        /* Linux LLC */
        PyModule_AddIntConstant(m, "AF_LLC", AF_LLC);
#endif

#ifdef USE_BLUETOOTH
        PyModule_AddIntConstant(m, "AF_BLUETOOTH", AF_BLUETOOTH);
        PyModule_AddIntConstant(m, "BTPROTO_L2CAP", BTPROTO_L2CAP);
        PyModule_AddIntConstant(m, "BTPROTO_HCI", BTPROTO_HCI);
        PyModule_AddIntConstant(m, "SOL_HCI", SOL_HCI);
        PyModule_AddIntConstant(m, "HCI_FILTER", HCI_FILTER);
#if !defined(__FreeBSD__)
        PyModule_AddIntConstant(m, "HCI_TIME_STAMP", HCI_TIME_STAMP);
        PyModule_AddIntConstant(m, "HCI_DATA_DIR", HCI_DATA_DIR);
        PyModule_AddIntConstant(m, "BTPROTO_SCO", BTPROTO_SCO);
#endif
        PyModule_AddIntConstant(m, "BTPROTO_RFCOMM", BTPROTO_RFCOMM);
        PyModule_AddStringConstant(m, "BDADDR_ANY", "00:00:00:00:00:00");
        PyModule_AddStringConstant(m, "BDADDR_LOCAL", "00:00:00:FF:FF:FF");
#endif

#ifdef HAVE_NETPACKET_PACKET_H
        PyModule_AddIntConstant(m, "AF_PACKET", AF_PACKET);
        PyModule_AddIntConstant(m, "PF_PACKET", PF_PACKET);
        PyModule_AddIntConstant(m, "PACKET_HOST", PACKET_HOST);
        PyModule_AddIntConstant(m, "PACKET_BROADCAST", PACKET_BROADCAST);
        PyModule_AddIntConstant(m, "PACKET_MULTICAST", PACKET_MULTICAST);
        PyModule_AddIntConstant(m, "PACKET_OTHERHOST", PACKET_OTHERHOST);
        PyModule_AddIntConstant(m, "PACKET_OUTGOING", PACKET_OUTGOING);
        PyModule_AddIntConstant(m, "PACKET_LOOPBACK", PACKET_LOOPBACK);
        PyModule_AddIntConstant(m, "PACKET_FASTROUTE", PACKET_FASTROUTE);
#endif

        /* Socket types */
        PyModule_AddIntConstant(m, "SOCK_STREAM", SOCK_STREAM);
        PyModule_AddIntConstant(m, "SOCK_DGRAM", SOCK_DGRAM);
#ifndef __BEOS__
/* We have incomplete socket support. */
        PyModule_AddIntConstant(m, "SOCK_RAW", SOCK_RAW);
        PyModule_AddIntConstant(m, "SOCK_SEQPACKET", SOCK_SEQPACKET);
#if defined(SOCK_RDM)
        PyModule_AddIntConstant(m, "SOCK_RDM", SOCK_RDM);
#endif
#endif

#ifdef  SO_DEBUG
        PyModule_AddIntConstant(m, "SO_DEBUG", SO_DEBUG);
#endif
#ifdef  SO_ACCEPTCONN
        PyModule_AddIntConstant(m, "SO_ACCEPTCONN", SO_ACCEPTCONN);
#endif
#ifdef  SO_REUSEADDR
        PyModule_AddIntConstant(m, "SO_REUSEADDR", SO_REUSEADDR);
#endif
#ifdef SO_EXCLUSIVEADDRUSE
        PyModule_AddIntConstant(m, "SO_EXCLUSIVEADDRUSE", SO_EXCLUSIVEADDRUSE);
#endif

#ifdef  SO_KEEPALIVE
        PyModule_AddIntConstant(m, "SO_KEEPALIVE", SO_KEEPALIVE);
#endif
#ifdef  SO_DONTROUTE
        PyModule_AddIntConstant(m, "SO_DONTROUTE", SO_DONTROUTE);
#endif
#ifdef  SO_BROADCAST
        PyModule_AddIntConstant(m, "SO_BROADCAST", SO_BROADCAST);
#endif
#ifdef  SO_USELOOPBACK
        PyModule_AddIntConstant(m, "SO_USELOOPBACK", SO_USELOOPBACK);
#endif
#ifdef  SO_LINGER
        PyModule_AddIntConstant(m, "SO_LINGER", SO_LINGER);
#endif
#ifdef  SO_OOBINLINE
        PyModule_AddIntConstant(m, "SO_OOBINLINE", SO_OOBINLINE);
#endif
#ifdef  SO_REUSEPORT
        PyModule_AddIntConstant(m, "SO_REUSEPORT", SO_REUSEPORT);
#endif
#ifdef  SO_SNDBUF
        PyModule_AddIntConstant(m, "SO_SNDBUF", SO_SNDBUF);
#endif
#ifdef  SO_RCVBUF
        PyModule_AddIntConstant(m, "SO_RCVBUF", SO_RCVBUF);
#endif
#ifdef  SO_SNDLOWAT
        PyModule_AddIntConstant(m, "SO_SNDLOWAT", SO_SNDLOWAT);
#endif
#ifdef  SO_RCVLOWAT
        PyModule_AddIntConstant(m, "SO_RCVLOWAT", SO_RCVLOWAT);
#endif
#ifdef  SO_SNDTIMEO
        PyModule_AddIntConstant(m, "SO_SNDTIMEO", SO_SNDTIMEO);
#endif
#ifdef  SO_RCVTIMEO
        PyModule_AddIntConstant(m, "SO_RCVTIMEO", SO_RCVTIMEO);
#endif
#ifdef  SO_ERROR
        PyModule_AddIntConstant(m, "SO_ERROR", SO_ERROR);
#endif
#ifdef  SO_TYPE
        PyModule_AddIntConstant(m, "SO_TYPE", SO_TYPE);
#endif

        /* Maximum number of connections for "listen" */
#ifdef  SOMAXCONN
        PyModule_AddIntConstant(m, "SOMAXCONN", SOMAXCONN);
#else
        PyModule_AddIntConstant(m, "SOMAXCONN", 5); /* Common value */
#endif

        /* Flags for send, recv */
#ifdef  MSG_OOB
        PyModule_AddIntConstant(m, "MSG_OOB", MSG_OOB);
#endif
#ifdef  MSG_PEEK
        PyModule_AddIntConstant(m, "MSG_PEEK", MSG_PEEK);
#endif
#ifdef  MSG_DONTROUTE
        PyModule_AddIntConstant(m, "MSG_DONTROUTE", MSG_DONTROUTE);
#endif
#ifdef  MSG_DONTWAIT
        PyModule_AddIntConstant(m, "MSG_DONTWAIT", MSG_DONTWAIT);
#endif
#ifdef  MSG_EOR
        PyModule_AddIntConstant(m, "MSG_EOR", MSG_EOR);
#endif
#ifdef  MSG_TRUNC
        PyModule_AddIntConstant(m, "MSG_TRUNC", MSG_TRUNC);
#endif
#ifdef  MSG_CTRUNC
        PyModule_AddIntConstant(m, "MSG_CTRUNC", MSG_CTRUNC);
#endif
#ifdef  MSG_WAITALL
        PyModule_AddIntConstant(m, "MSG_WAITALL", MSG_WAITALL);
#endif
#ifdef  MSG_BTAG
        PyModule_AddIntConstant(m, "MSG_BTAG", MSG_BTAG);
#endif
#ifdef  MSG_ETAG
        PyModule_AddIntConstant(m, "MSG_ETAG", MSG_ETAG);
#endif

        /* Protocol level and numbers, usable for [gs]etsockopt */
#ifdef  SOL_SOCKET
        PyModule_AddIntConstant(m, "SOL_SOCKET", SOL_SOCKET);
#endif
#ifdef  SOL_IP
        PyModule_AddIntConstant(m, "SOL_IP", SOL_IP);
#else
        PyModule_AddIntConstant(m, "SOL_IP", 0);
#endif
#ifdef  SOL_IPX
        PyModule_AddIntConstant(m, "SOL_IPX", SOL_IPX);
#endif
#ifdef  SOL_AX25
        PyModule_AddIntConstant(m, "SOL_AX25", SOL_AX25);
#endif
#ifdef  SOL_ATALK
        PyModule_AddIntConstant(m, "SOL_ATALK", SOL_ATALK);
#endif
#ifdef  SOL_NETROM
        PyModule_AddIntConstant(m, "SOL_NETROM", SOL_NETROM);
#endif
#ifdef  SOL_ROSE
        PyModule_AddIntConstant(m, "SOL_ROSE", SOL_ROSE);
#endif
#ifdef  SOL_TCP
        PyModule_AddIntConstant(m, "SOL_TCP", SOL_TCP);
#else
        PyModule_AddIntConstant(m, "SOL_TCP", 6);
#endif
#ifdef  SOL_UDP
        PyModule_AddIntConstant(m, "SOL_UDP", SOL_UDP);
#else
        PyModule_AddIntConstant(m, "SOL_UDP", 17);
#endif
#ifdef  IPPROTO_IP
        PyModule_AddIntConstant(m, "IPPROTO_IP", IPPROTO_IP);
#else
        PyModule_AddIntConstant(m, "IPPROTO_IP", 0);
#endif
#ifdef  IPPROTO_HOPOPTS
        PyModule_AddIntConstant(m, "IPPROTO_HOPOPTS", IPPROTO_HOPOPTS);
#endif
#ifdef  IPPROTO_ICMP
        PyModule_AddIntConstant(m, "IPPROTO_ICMP", IPPROTO_ICMP);
#else
        PyModule_AddIntConstant(m, "IPPROTO_ICMP", 1);
#endif
#ifdef  IPPROTO_IGMP
        PyModule_AddIntConstant(m, "IPPROTO_IGMP", IPPROTO_IGMP);
#endif
#ifdef  IPPROTO_GGP
        PyModule_AddIntConstant(m, "IPPROTO_GGP", IPPROTO_GGP);
#endif
#ifdef  IPPROTO_IPV4
        PyModule_AddIntConstant(m, "IPPROTO_IPV4", IPPROTO_IPV4);
#endif
#ifdef  IPPROTO_IPV6
        PyModule_AddIntConstant(m, "IPPROTO_IPV6", IPPROTO_IPV6);
#endif
#ifdef  IPPROTO_IPIP
        PyModule_AddIntConstant(m, "IPPROTO_IPIP", IPPROTO_IPIP);
#endif
#ifdef  IPPROTO_TCP
        PyModule_AddIntConstant(m, "IPPROTO_TCP", IPPROTO_TCP);
#else
        PyModule_AddIntConstant(m, "IPPROTO_TCP", 6);
#endif
#ifdef  IPPROTO_EGP
        PyModule_AddIntConstant(m, "IPPROTO_EGP", IPPROTO_EGP);
#endif
#ifdef  IPPROTO_PUP
        PyModule_AddIntConstant(m, "IPPROTO_PUP", IPPROTO_PUP);
#endif
#ifdef  IPPROTO_UDP
        PyModule_AddIntConstant(m, "IPPROTO_UDP", IPPROTO_UDP);
#else
        PyModule_AddIntConstant(m, "IPPROTO_UDP", 17);
#endif
#ifdef  IPPROTO_IDP
        PyModule_AddIntConstant(m, "IPPROTO_IDP", IPPROTO_IDP);
#endif
#ifdef  IPPROTO_HELLO
        PyModule_AddIntConstant(m, "IPPROTO_HELLO", IPPROTO_HELLO);
#endif
#ifdef  IPPROTO_ND
        PyModule_AddIntConstant(m, "IPPROTO_ND", IPPROTO_ND);
#endif
#ifdef  IPPROTO_TP
        PyModule_AddIntConstant(m, "IPPROTO_TP", IPPROTO_TP);
#endif
#ifdef  IPPROTO_IPV6
        PyModule_AddIntConstant(m, "IPPROTO_IPV6", IPPROTO_IPV6);
#endif
#ifdef  IPPROTO_ROUTING
        PyModule_AddIntConstant(m, "IPPROTO_ROUTING", IPPROTO_ROUTING);
#endif
#ifdef  IPPROTO_FRAGMENT
        PyModule_AddIntConstant(m, "IPPROTO_FRAGMENT", IPPROTO_FRAGMENT);
#endif
#ifdef  IPPROTO_RSVP
        PyModule_AddIntConstant(m, "IPPROTO_RSVP", IPPROTO_RSVP);
#endif
#ifdef  IPPROTO_GRE
        PyModule_AddIntConstant(m, "IPPROTO_GRE", IPPROTO_GRE);
#endif
#ifdef  IPPROTO_ESP
        PyModule_AddIntConstant(m, "IPPROTO_ESP", IPPROTO_ESP);
#endif
#ifdef  IPPROTO_AH
        PyModule_AddIntConstant(m, "IPPROTO_AH", IPPROTO_AH);
#endif
#ifdef  IPPROTO_MOBILE
        PyModule_AddIntConstant(m, "IPPROTO_MOBILE", IPPROTO_MOBILE);
#endif
#ifdef  IPPROTO_ICMPV6
        PyModule_AddIntConstant(m, "IPPROTO_ICMPV6", IPPROTO_ICMPV6);
#endif
#ifdef  IPPROTO_NONE
        PyModule_AddIntConstant(m, "IPPROTO_NONE", IPPROTO_NONE);
#endif
#ifdef  IPPROTO_DSTOPTS
        PyModule_AddIntConstant(m, "IPPROTO_DSTOPTS", IPPROTO_DSTOPTS);
#endif
#ifdef  IPPROTO_XTP
        PyModule_AddIntConstant(m, "IPPROTO_XTP", IPPROTO_XTP);
#endif
#ifdef  IPPROTO_EON
        PyModule_AddIntConstant(m, "IPPROTO_EON", IPPROTO_EON);
#endif
#ifdef  IPPROTO_PIM
        PyModule_AddIntConstant(m, "IPPROTO_PIM", IPPROTO_PIM);
#endif
#ifdef  IPPROTO_IPCOMP
        PyModule_AddIntConstant(m, "IPPROTO_IPCOMP", IPPROTO_IPCOMP);
#endif
#ifdef  IPPROTO_VRRP
        PyModule_AddIntConstant(m, "IPPROTO_VRRP", IPPROTO_VRRP);
#endif
#ifdef  IPPROTO_BIP
        PyModule_AddIntConstant(m, "IPPROTO_BIP", IPPROTO_BIP);
#endif
/**/
#ifdef  IPPROTO_RAW
        PyModule_AddIntConstant(m, "IPPROTO_RAW", IPPROTO_RAW);
#else
        PyModule_AddIntConstant(m, "IPPROTO_RAW", 255);
#endif
#ifdef  IPPROTO_MAX
        PyModule_AddIntConstant(m, "IPPROTO_MAX", IPPROTO_MAX);
#endif

        /* Some port configuration */
#ifdef  IPPORT_RESERVED
        PyModule_AddIntConstant(m, "IPPORT_RESERVED", IPPORT_RESERVED);
#else
        PyModule_AddIntConstant(m, "IPPORT_RESERVED", 1024);
#endif
#ifdef  IPPORT_USERRESERVED
        PyModule_AddIntConstant(m, "IPPORT_USERRESERVED", IPPORT_USERRESERVED);
#else
        PyModule_AddIntConstant(m, "IPPORT_USERRESERVED", 5000);
#endif

        /* Some reserved IP v.4 addresses */
#ifdef  INADDR_ANY
        PyModule_AddIntConstant(m, "INADDR_ANY", INADDR_ANY);
#else
        PyModule_AddIntConstant(m, "INADDR_ANY", 0x00000000);
#endif
#ifdef  INADDR_BROADCAST
        PyModule_AddIntConstant(m, "INADDR_BROADCAST", INADDR_BROADCAST);
#else
        PyModule_AddIntConstant(m, "INADDR_BROADCAST", 0xffffffff);
#endif
#ifdef  INADDR_LOOPBACK
        PyModule_AddIntConstant(m, "INADDR_LOOPBACK", INADDR_LOOPBACK);
#else
        PyModule_AddIntConstant(m, "INADDR_LOOPBACK", 0x7F000001);
#endif
#ifdef  INADDR_UNSPEC_GROUP
        PyModule_AddIntConstant(m, "INADDR_UNSPEC_GROUP", INADDR_UNSPEC_GROUP);
#else
        PyModule_AddIntConstant(m, "INADDR_UNSPEC_GROUP", 0xe0000000);
#endif
#ifdef  INADDR_ALLHOSTS_GROUP
        PyModule_AddIntConstant(m, "INADDR_ALLHOSTS_GROUP",
                                INADDR_ALLHOSTS_GROUP);
#else
        PyModule_AddIntConstant(m, "INADDR_ALLHOSTS_GROUP", 0xe0000001);
#endif
#ifdef  INADDR_MAX_LOCAL_GROUP
        PyModule_AddIntConstant(m, "INADDR_MAX_LOCAL_GROUP",
                                INADDR_MAX_LOCAL_GROUP);
#else
        PyModule_AddIntConstant(m, "INADDR_MAX_LOCAL_GROUP", 0xe00000ff);
#endif
#ifdef  INADDR_NONE
        PyModule_AddIntConstant(m, "INADDR_NONE", INADDR_NONE);
#else
        PyModule_AddIntConstant(m, "INADDR_NONE", 0xffffffff);
#endif

        /* IPv4 [gs]etsockopt options */
#ifdef  IP_OPTIONS
        PyModule_AddIntConstant(m, "IP_OPTIONS", IP_OPTIONS);
#endif
#ifdef  IP_HDRINCL
        PyModule_AddIntConstant(m, "IP_HDRINCL", IP_HDRINCL);
#endif
#ifdef  IP_TOS
        PyModule_AddIntConstant(m, "IP_TOS", IP_TOS);
#endif
#ifdef  IP_TTL
        PyModule_AddIntConstant(m, "IP_TTL", IP_TTL);
#endif
#ifdef  IP_RECVOPTS
        PyModule_AddIntConstant(m, "IP_RECVOPTS", IP_RECVOPTS);
#endif
#ifdef  IP_RECVRETOPTS
        PyModule_AddIntConstant(m, "IP_RECVRETOPTS", IP_RECVRETOPTS);
#endif
#ifdef  IP_RECVDSTADDR
        PyModule_AddIntConstant(m, "IP_RECVDSTADDR", IP_RECVDSTADDR);
#endif
#ifdef  IP_RETOPTS
        PyModule_AddIntConstant(m, "IP_RETOPTS", IP_RETOPTS);
#endif
#ifdef  IP_MULTICAST_IF
        PyModule_AddIntConstant(m, "IP_MULTICAST_IF", IP_MULTICAST_IF);
#endif
#ifdef  IP_MULTICAST_TTL
        PyModule_AddIntConstant(m, "IP_MULTICAST_TTL", IP_MULTICAST_TTL);
#endif
#ifdef  IP_MULTICAST_LOOP
        PyModule_AddIntConstant(m, "IP_MULTICAST_LOOP", IP_MULTICAST_LOOP);
#endif
#ifdef  IP_ADD_MEMBERSHIP
        PyModule_AddIntConstant(m, "IP_ADD_MEMBERSHIP", IP_ADD_MEMBERSHIP);
#endif
#ifdef  IP_DROP_MEMBERSHIP
        PyModule_AddIntConstant(m, "IP_DROP_MEMBERSHIP", IP_DROP_MEMBERSHIP);
#endif
#ifdef  IP_DEFAULT_MULTICAST_TTL
        PyModule_AddIntConstant(m, "IP_DEFAULT_MULTICAST_TTL",
                                IP_DEFAULT_MULTICAST_TTL);
#endif
#ifdef  IP_DEFAULT_MULTICAST_LOOP
        PyModule_AddIntConstant(m, "IP_DEFAULT_MULTICAST_LOOP",
                                IP_DEFAULT_MULTICAST_LOOP);
#endif
#ifdef  IP_MAX_MEMBERSHIPS
        PyModule_AddIntConstant(m, "IP_MAX_MEMBERSHIPS", IP_MAX_MEMBERSHIPS);
#endif

        /* IPv6 [gs]etsockopt options, defined in RFC2553 */
#ifdef  IPV6_JOIN_GROUP
        PyModule_AddIntConstant(m, "IPV6_JOIN_GROUP", IPV6_JOIN_GROUP);
#endif
#ifdef  IPV6_LEAVE_GROUP
        PyModule_AddIntConstant(m, "IPV6_LEAVE_GROUP", IPV6_LEAVE_GROUP);
#endif
#ifdef  IPV6_MULTICAST_HOPS
        PyModule_AddIntConstant(m, "IPV6_MULTICAST_HOPS", IPV6_MULTICAST_HOPS);
#endif
#ifdef  IPV6_MULTICAST_IF
        PyModule_AddIntConstant(m, "IPV6_MULTICAST_IF", IPV6_MULTICAST_IF);
#endif
#ifdef  IPV6_MULTICAST_LOOP
        PyModule_AddIntConstant(m, "IPV6_MULTICAST_LOOP", IPV6_MULTICAST_LOOP);
#endif
#ifdef  IPV6_UNICAST_HOPS
        PyModule_AddIntConstant(m, "IPV6_UNICAST_HOPS", IPV6_UNICAST_HOPS);
#endif
        /* Additional IPV6 socket options, defined in RFC 3493 */
#ifdef IPV6_V6ONLY
        PyModule_AddIntConstant(m, "IPV6_V6ONLY", IPV6_V6ONLY);
#endif
        /* Advanced IPV6 socket options, from RFC 3542 */
#ifdef IPV6_CHECKSUM
        PyModule_AddIntConstant(m, "IPV6_CHECKSUM", IPV6_CHECKSUM);
#endif
#ifdef IPV6_DONTFRAG
        PyModule_AddIntConstant(m, "IPV6_DONTFRAG", IPV6_DONTFRAG);
#endif
#ifdef IPV6_DSTOPTS
        PyModule_AddIntConstant(m, "IPV6_DSTOPTS", IPV6_DSTOPTS);
#endif
#ifdef IPV6_HOPLIMIT
        PyModule_AddIntConstant(m, "IPV6_HOPLIMIT", IPV6_HOPLIMIT);
#endif
#ifdef IPV6_HOPOPTS
        PyModule_AddIntConstant(m, "IPV6_HOPOPTS", IPV6_HOPOPTS);
#endif
#ifdef IPV6_NEXTHOP
        PyModule_AddIntConstant(m, "IPV6_NEXTHOP", IPV6_NEXTHOP);
#endif
#ifdef IPV6_PATHMTU
        PyModule_AddIntConstant(m, "IPV6_PATHMTU", IPV6_PATHMTU);
#endif
#ifdef IPV6_PKTINFO
        PyModule_AddIntConstant(m, "IPV6_PKTINFO", IPV6_PKTINFO);
#endif
#ifdef IPV6_RECVDSTOPTS
        PyModule_AddIntConstant(m, "IPV6_RECVDSTOPTS", IPV6_RECVDSTOPTS);
#endif
#ifdef IPV6_RECVHOPLIMIT
        PyModule_AddIntConstant(m, "IPV6_RECVHOPLIMIT", IPV6_RECVHOPLIMIT);
#endif
#ifdef IPV6_RECVHOPOPTS
        PyModule_AddIntConstant(m, "IPV6_RECVHOPOPTS", IPV6_RECVHOPOPTS);
#endif
#ifdef IPV6_RECVPKTINFO
        PyModule_AddIntConstant(m, "IPV6_RECVPKTINFO", IPV6_RECVPKTINFO);
#endif
#ifdef IPV6_RECVRTHDR
        PyModule_AddIntConstant(m, "IPV6_RECVRTHDR", IPV6_RECVRTHDR);
#endif
#ifdef IPV6_RECVTCLASS
        PyModule_AddIntConstant(m, "IPV6_RECVTCLASS", IPV6_RECVTCLASS);
#endif
#ifdef IPV6_RTHDR
        PyModule_AddIntConstant(m, "IPV6_RTHDR", IPV6_RTHDR);
#endif
#ifdef IPV6_RTHDRDSTOPTS
        PyModule_AddIntConstant(m, "IPV6_RTHDRDSTOPTS", IPV6_RTHDRDSTOPTS);
#endif
#ifdef IPV6_RTHDR_TYPE_0
        PyModule_AddIntConstant(m, "IPV6_RTHDR_TYPE_0", IPV6_RTHDR_TYPE_0);
#endif
#ifdef IPV6_RECVPATHMTU
        PyModule_AddIntConstant(m, "IPV6_RECVPATHMTU", IPV6_RECVPATHMTU);
#endif
#ifdef IPV6_TCLASS
        PyModule_AddIntConstant(m, "IPV6_TCLASS", IPV6_TCLASS);
#endif
#ifdef IPV6_USE_MIN_MTU
        PyModule_AddIntConstant(m, "IPV6_USE_MIN_MTU", IPV6_USE_MIN_MTU);
#endif

        /* TCP options */
#ifdef  TCP_NODELAY
        PyModule_AddIntConstant(m, "TCP_NODELAY", TCP_NODELAY);
#endif
#ifdef  TCP_MAXSEG
        PyModule_AddIntConstant(m, "TCP_MAXSEG", TCP_MAXSEG);
#endif
#ifdef  TCP_CORK
        PyModule_AddIntConstant(m, "TCP_CORK", TCP_CORK);
#endif
#ifdef  TCP_KEEPIDLE
        PyModule_AddIntConstant(m, "TCP_KEEPIDLE", TCP_KEEPIDLE);
#endif
#ifdef  TCP_KEEPINTVL
        PyModule_AddIntConstant(m, "TCP_KEEPINTVL", TCP_KEEPINTVL);
#endif
#ifdef  TCP_KEEPCNT
        PyModule_AddIntConstant(m, "TCP_KEEPCNT", TCP_KEEPCNT);
#endif
#ifdef  TCP_SYNCNT
        PyModule_AddIntConstant(m, "TCP_SYNCNT", TCP_SYNCNT);
#endif
#ifdef  TCP_LINGER2
        PyModule_AddIntConstant(m, "TCP_LINGER2", TCP_LINGER2);
#endif
#ifdef  TCP_DEFER_ACCEPT
        PyModule_AddIntConstant(m, "TCP_DEFER_ACCEPT", TCP_DEFER_ACCEPT);
#endif
#ifdef  TCP_WINDOW_CLAMP
        PyModule_AddIntConstant(m, "TCP_WINDOW_CLAMP", TCP_WINDOW_CLAMP);
#endif
#ifdef  TCP_INFO
        PyModule_AddIntConstant(m, "TCP_INFO", TCP_INFO);
#endif
#ifdef  TCP_QUICKACK
        PyModule_AddIntConstant(m, "TCP_QUICKACK", TCP_QUICKACK);
#endif


        /* IPX options */
#ifdef  IPX_TYPE
        PyModule_AddIntConstant(m, "IPX_TYPE", IPX_TYPE);
#endif

        /* get{addr,name}info parameters */
#ifdef EAI_ADDRFAMILY
        PyModule_AddIntConstant(m, "EAI_ADDRFAMILY", EAI_ADDRFAMILY);
#endif
#ifdef EAI_AGAIN
        PyModule_AddIntConstant(m, "EAI_AGAIN", EAI_AGAIN);
#endif
#ifdef EAI_BADFLAGS
        PyModule_AddIntConstant(m, "EAI_BADFLAGS", EAI_BADFLAGS);
#endif
#ifdef EAI_FAIL
        PyModule_AddIntConstant(m, "EAI_FAIL", EAI_FAIL);
#endif
#ifdef EAI_FAMILY
        PyModule_AddIntConstant(m, "EAI_FAMILY", EAI_FAMILY);
#endif
#ifdef EAI_MEMORY
        PyModule_AddIntConstant(m, "EAI_MEMORY", EAI_MEMORY);
#endif
#ifdef EAI_NODATA
        PyModule_AddIntConstant(m, "EAI_NODATA", EAI_NODATA);
#endif
#ifdef EAI_NONAME
        PyModule_AddIntConstant(m, "EAI_NONAME", EAI_NONAME);
#endif
#ifdef EAI_OVERFLOW
        PyModule_AddIntConstant(m, "EAI_OVERFLOW", EAI_OVERFLOW);
#endif
#ifdef EAI_SERVICE
        PyModule_AddIntConstant(m, "EAI_SERVICE", EAI_SERVICE);
#endif
#ifdef EAI_SOCKTYPE
        PyModule_AddIntConstant(m, "EAI_SOCKTYPE", EAI_SOCKTYPE);
#endif
#ifdef EAI_SYSTEM
        PyModule_AddIntConstant(m, "EAI_SYSTEM", EAI_SYSTEM);
#endif
#ifdef EAI_BADHINTS
        PyModule_AddIntConstant(m, "EAI_BADHINTS", EAI_BADHINTS);
#endif
#ifdef EAI_PROTOCOL
        PyModule_AddIntConstant(m, "EAI_PROTOCOL", EAI_PROTOCOL);
#endif
#ifdef EAI_MAX
        PyModule_AddIntConstant(m, "EAI_MAX", EAI_MAX);
#endif
#ifdef AI_PASSIVE
        PyModule_AddIntConstant(m, "AI_PASSIVE", AI_PASSIVE);
#endif
#ifdef AI_CANONNAME
        PyModule_AddIntConstant(m, "AI_CANONNAME", AI_CANONNAME);
#endif
#ifdef AI_NUMERICHOST
        PyModule_AddIntConstant(m, "AI_NUMERICHOST", AI_NUMERICHOST);
#endif
#ifdef AI_NUMERICSERV
        PyModule_AddIntConstant(m, "AI_NUMERICSERV", AI_NUMERICSERV);
#endif
#ifdef AI_MASK
        PyModule_AddIntConstant(m, "AI_MASK", AI_MASK);
#endif
#ifdef AI_ALL
        PyModule_AddIntConstant(m, "AI_ALL", AI_ALL);
#endif
#ifdef AI_V4MAPPED_CFG
        PyModule_AddIntConstant(m, "AI_V4MAPPED_CFG", AI_V4MAPPED_CFG);
#endif
#ifdef AI_ADDRCONFIG
        PyModule_AddIntConstant(m, "AI_ADDRCONFIG", AI_ADDRCONFIG);
#endif
#ifdef AI_V4MAPPED
        PyModule_AddIntConstant(m, "AI_V4MAPPED", AI_V4MAPPED);
#endif
#ifdef AI_DEFAULT
        PyModule_AddIntConstant(m, "AI_DEFAULT", AI_DEFAULT);
#endif
#ifdef NI_MAXHOST
        PyModule_AddIntConstant(m, "NI_MAXHOST", NI_MAXHOST);
#endif
#ifdef NI_MAXSERV
        PyModule_AddIntConstant(m, "NI_MAXSERV", NI_MAXSERV);
#endif
#ifdef NI_NOFQDN
        PyModule_AddIntConstant(m, "NI_NOFQDN", NI_NOFQDN);
#endif
#ifdef NI_NUMERICHOST
        PyModule_AddIntConstant(m, "NI_NUMERICHOST", NI_NUMERICHOST);
#endif
#ifdef NI_NAMEREQD
        PyModule_AddIntConstant(m, "NI_NAMEREQD", NI_NAMEREQD);
#endif
#ifdef NI_NUMERICSERV
        PyModule_AddIntConstant(m, "NI_NUMERICSERV", NI_NUMERICSERV);
#endif
#ifdef NI_DGRAM
        PyModule_AddIntConstant(m, "NI_DGRAM", NI_DGRAM);
#endif

        /* shutdown() parameters */
#ifdef SHUT_RD
        PyModule_AddIntConstant(m, "SHUT_RD", SHUT_RD);
#elif defined(SD_RECEIVE)
        PyModule_AddIntConstant(m, "SHUT_RD", SD_RECEIVE);
#else
        PyModule_AddIntConstant(m, "SHUT_RD", 0);
#endif
#ifdef SHUT_WR
        PyModule_AddIntConstant(m, "SHUT_WR", SHUT_WR);
#elif defined(SD_SEND)
        PyModule_AddIntConstant(m, "SHUT_WR", SD_SEND);
#else
        PyModule_AddIntConstant(m, "SHUT_WR", 1);
#endif
#ifdef SHUT_RDWR
        PyModule_AddIntConstant(m, "SHUT_RDWR", SHUT_RDWR);
#elif defined(SD_BOTH)
        PyModule_AddIntConstant(m, "SHUT_RDWR", SD_BOTH);
#else
        PyModule_AddIntConstant(m, "SHUT_RDWR", 2);
#endif

        /* Initialize gethostbyname lock */
#if defined(USE_GETHOSTBYNAME_LOCK) || defined(USE_GETADDRINFO_LOCK)
        netdb_lock = PyThread_allocate_lock();
#endif
}


#ifndef HAVE_INET_PTON

/* Simplistic emulation code for inet_pton that only works for IPv4 */
/* These are not exposed because they do not set errno properly */

int
inet_pton(int af, const char *src, void *dst)
{
        if (af == AF_INET) {
                long packed_addr;
                packed_addr = inet_addr(src);
                if (packed_addr == INADDR_NONE)
                        return 0;
                memcpy(dst, &packed_addr, 4);
                return 1;
        }
        /* Should set errno to EAFNOSUPPORT */
        return -1;
}

const char *
inet_ntop(int af, const void *src, char *dst, socklen_t size)
{
        if (af == AF_INET) {
                struct in_addr packed_addr;
                if (size < 16)
                        /* Should set errno to ENOSPC. */
                        return NULL;
                memcpy(&packed_addr, src, sizeof(packed_addr));
                return strncpy(dst, inet_ntoa(packed_addr), size);
        }
        /* Should set errno to EAFNOSUPPORT */
        return NULL;
}

#endif