/* 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, AF_NETLINK and AF_TIPC 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.

- an AF_TIPC socket address is expressed as

 (addr_type, v1, v2, v3 [, scope]); where addr_type can be one of:

	TIPC_ADDR_NAMESEQ, TIPC_ADDR_NAME, and TIPC_ADDR_ID;

  and scope can be one of:

	TIPC_ZONE_SCOPE, TIPC_CLUSTER_SCOPE, and TIPC_NODE_SCOPE.

  The meaning of v1, v2 and v3 depends on the value of addr_type:

	if addr_type is TIPC_ADDR_NAME:

		v1 is the server type

		v2 is the port identifier

		v3 is ignored

	if addr_type is TIPC_ADDR_NAMESEQ:

		v1 is the server type

		v2 is the lower port number

		v3 is the upper port number

	if addr_type is TIPC_ADDR_ID:

		v1 is the node

		v2 is the ref

		v3 is ignored

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

#if !defined(NTDDI_VERSION) || (NTDDI_VERSION < NTDDI_LONGHORN)

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

#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();

	/* PyErr_SetExcFromWindowsErr() invokes FormatMessage() which

	   recognizes the error codes used by both GetLastError() and

	   WSAGetLastError */

	if (err_no)

		return PyErr_SetExcFromWindowsErr(socket_error, err_no);

#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