/*

  This file is part of libmicrohttpd

  Copyright (C) 2014-2016 Karlson2k (Evgeny Grin)

  This library is free software; you can redistribute it and/or

  modify it under the terms of the GNU Lesser General Public

  License as published by the Free Software Foundation; either

  version 2.1 of the License, or (at your option) any later version.

  This library is distributed in the hope that it will be useful,

  but WITHOUT ANY WARRANTY; without even the implied warranty of

  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public

  License along with this library; if not, write to the Free Software

  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

*/

/**

 * @file microhttpd/mhd_sockets.c

 * @brief  Header for platform-independent sockets abstraction

 * @author Karlson2k (Evgeny Grin)

 *

 * Provides basic abstraction for sockets.

 * Any functions can be implemented as macro on some platforms

 * unless explicitly marked otherwise.

 * Any function argument can be skipped in macro, so avoid

 * variable modification in function parameters.

 */

#ifndef MHD_SOCKETS_H

#define MHD_SOCKETS_H 1

#include "mhd_options.h"

#include <errno.h>

#if !defined(MHD_POSIX_SOCKETS) && !defined(MHD_WINSOCK_SOCKETS)

#  if !defined(_WIN32) || defined(__CYGWIN__)

#    define MHD_POSIX_SOCKETS 1

#  else  /* defined(_WIN32) && !defined(__CYGWIN__) */

#    define MHD_WINSOCK_SOCKETS 1

#  endif /* defined(_WIN32) && !defined(__CYGWIN__) */

#endif /* !MHD_POSIX_SOCKETS && !MHD_WINSOCK_SOCKETS */

/*

 * MHD require headers that define socket type, socket basic functions

 * (socket(), accept(), listen(), bind(), send(), recv(), select()), socket

 * parameters like SOCK_CLOEXEC, SOCK_NONBLOCK, additional socket functions

 * (poll(), epoll(), accept4()), struct timeval and other types, required

 * for socket function.

 */

#if defined(MHD_POSIX_SOCKETS)

#  ifdef HAVE_SYS_TYPES_H

#    include <sys/types.h> /* required on old platforms */

#  endif

#  ifdef HAVE_SYS_SOCKET_H

#    include <sys/socket.h>

#  endif

#  if defined(__VXWORKS__) || defined(__vxworks) || defined(OS_VXWORKS)

#    ifdef HAVE_SOCKLIB_H

#      include <sockLib.h>

#    endif /* HAVE_SOCKLIB_H */

#    ifdef HAVE_INETLIB_H

#      include <inetLib.h>

#    endif /* HAVE_INETLIB_H */

#    include <strings.h>  /* required for FD_SET (bzero() function) */

#  endif /* __VXWORKS__ || __vxworks || OS_VXWORKS */

#  ifdef HAVE_NETINET_IN_H

#    include <netinet/in.h>

#  endif /* HAVE_NETINET_IN_H */

#  ifdef HAVE_ARPA_INET_H

#    include <arpa/inet.h>

#  endif

#  ifdef HAVE_NET_IF_H

#    include <net/if.h>

#  endif

#  ifdef HAVE_SYS_TIME_H

#    include <sys/time.h>

#  endif

#  ifdef HAVE_TIME_H

#    include <time.h>

#  endif

#  ifdef HAVE_NETDB_H

#    include <netdb.h>

#  endif

#  ifdef HAVE_SYS_SELECT_H

#    include <sys/select.h>

#  endif

#  ifdef EPOLL_SUPPORT

#    include <sys/epoll.h>

#  endif

#  ifdef HAVE_NETINET_TCP_H

     /* for TCP_FASTOPEN and TCP_CORK */

#    include <netinet/tcp.h>

#  endif

#  ifdef HAVE_STRING_H

#    include <string.h> /* for strerror() */

#  endif

#elif defined(MHD_WINSOCK_SOCKETS)

#  ifndef WIN32_LEAN_AND_MEAN

#    define WIN32_LEAN_AND_MEAN 1

#  endif /* !WIN32_LEAN_AND_MEAN */

#  include <winsock2.h>

#  include <ws2tcpip.h>

#endif /* MHD_WINSOCK_SOCKETS */

#if defined(HAVE_POLL_H) && defined(HAVE_POLL)

#  include <poll.h>

#endif

#include <stddef.h>

#if defined(_MSC_FULL_VER) && !defined (_SSIZE_T_DEFINED)

#  include <stdint.h>

#  define _SSIZE_T_DEFINED

   typedef intptr_t ssize_t;

#endif /* !_SSIZE_T_DEFINED */

#include "mhd_limits.h"

#ifdef _MHD_FD_SETSIZE_IS_DEFAULT

#  define _MHD_SYS_DEFAULT_FD_SETSIZE FD_SETSIZE

#else  /* ! _MHD_FD_SETSIZE_IS_DEFAULT */

#  include "sysfdsetsize.h"

#  define _MHD_SYS_DEFAULT_FD_SETSIZE get_system_fdsetsize_value()

#endif /* ! _MHD_FD_SETSIZE_IS_DEFAULT */

#ifndef MHD_PANIC

#  include <stdio.h>

#  include <stdlib.h>

/* Simple implementation of MHD_PANIC, to be used outside lib */

#  define MHD_PANIC(msg) do { fprintf (stderr,           \

     "Abnormal termination at %d line in file %s: %s\n", \

     (int)__LINE__, __FILE__, msg); abort();} while(0)

#endif /* ! MHD_PANIC */

#ifndef MHD_SOCKET_DEFINED

/**

 * MHD_socket is type for socket FDs

 */

#  if defined(MHD_POSIX_SOCKETS)

     typedef int MHD_socket;

#    define MHD_INVALID_SOCKET (-1)

#  elif defined(MHD_WINSOCK_SOCKETS)

     typedef SOCKET MHD_socket;

#    define MHD_INVALID_SOCKET (INVALID_SOCKET)

#  endif /* MHD_WINSOCK_SOCKETS */

#  define MHD_SOCKET_DEFINED 1

#endif /* ! MHD_SOCKET_DEFINED */

#ifdef SOCK_CLOEXEC

#  define MAYBE_SOCK_CLOEXEC SOCK_CLOEXEC

#else  /* ! SOCK_CLOEXEC */

#  define MAYBE_SOCK_CLOEXEC 0

#endif /* ! SOCK_CLOEXEC */

#ifdef HAVE_SOCK_NONBLOCK

#  define MAYBE_SOCK_NONBLOCK SOCK_NONBLOCK

#else  /* ! HAVE_SOCK_NONBLOCK */

#  define MAYBE_SOCK_NONBLOCK 0

#endif /* ! HAVE_SOCK_NONBLOCK */

#ifdef MSG_NOSIGNAL

#  define MAYBE_MSG_NOSIGNAL MSG_NOSIGNAL

#else  /* ! MSG_NOSIGNAL */

#  define MAYBE_MSG_NOSIGNAL 0

#endif /* ! MSG_NOSIGNAL */

#if !defined(SHUT_WR) && defined(SD_SEND)

#  define SHUT_WR SD_SEND

#endif

#if !defined(SHUT_RD) && defined(SD_RECEIVE)

#  define SHUT_RD SD_RECEIVE

#endif

#if !defined(SHUT_RDWR) && defined(SD_BOTH)

#  define SHUT_RDWR SD_BOTH

#endif

#if HAVE_ACCEPT4+0 != 0 && (defined(HAVE_SOCK_NONBLOCK) || defined(SOCK_CLOEXEC))

#  define USE_ACCEPT4 1

#endif

#if defined(HAVE_EPOLL_CREATE1) && defined(EPOLL_CLOEXEC)

#  define USE_EPOLL_CREATE1 1

#endif /* HAVE_EPOLL_CREATE1 && EPOLL_CLOEXEC */

#ifdef TCP_FASTOPEN

/**

 * Default TCP fastopen queue size.

 */

#define MHD_TCP_FASTOPEN_QUEUE_SIZE_DEFAULT 10

#endif

/**

 * MHD_SCKT_OPT_BOOL_ is type for bool parameters for setsockopt()/getsockopt()

 */

#ifdef MHD_POSIX_SOCKETS

  typedef int MHD_SCKT_OPT_BOOL_;

#else /* MHD_WINSOCK_SOCKETS */

  typedef BOOL MHD_SCKT_OPT_BOOL_;

#endif /* MHD_WINSOCK_SOCKETS */

/**

 * MHD_SCKT_SEND_SIZE_ is type used to specify size for send and recv

 * functions

 */

#if !defined(MHD_WINSOCK_SOCKETS)

  typedef size_t MHD_SCKT_SEND_SIZE_;

#else

  typedef int MHD_SCKT_SEND_SIZE_;

#endif

/**

 * MHD_SCKT_SEND_MAX_SIZE_ is maximum send()/recv() size value.

 */

#if !defined(MHD_WINSOCK_SOCKETS)

#  define MHD_SCKT_SEND_MAX_SIZE_ SSIZE_MAX

#else

#  define MHD_SCKT_SEND_MAX_SIZE_ INT_MAX

#endif

/**

 * MHD_socket_close_(fd) close any FDs (non-W32) / close only socket

 * FDs (W32).  Note that on HP-UNIX, this function may leak the FD if

 * errno is set to EINTR.  Do not use HP-UNIX.

 *

 * @param fd descriptor to close

 * @return boolean true on success (error codes like EINTR and EIO are

 *         counted as success, only EBADF counts as an error!),

 *         boolean false otherwise.

 */

#if !defined(MHD_WINSOCK_SOCKETS)

#  define MHD_socket_close_(fd) ((0 == close((fd))) || (EBADF != errno))

#else

#  define MHD_socket_close_(fd) (0 == closesocket((fd)))

#endif

/**

 * MHD_socket_close_chk_(fd) close socket and abort execution

 * if error is detected.

 * @param fd socket to close

 */

#define MHD_socket_close_chk_(fd) do {        \

    if (!MHD_socket_close_(fd))               \

      MHD_PANIC(_("Close socket failed.\n")); \

  } while(0)

/**

 * MHD_send_ is wrapper for system's send()

 * @param s the socket to use

 * @param b the buffer with data to send

 * @param l the length of data in @a b

 * @return ssize_t type value

 */

#define MHD_send_(s,b,l) \

  ((ssize_t)send((s),(const void*)(b),((MHD_SCKT_SEND_SIZE_)l), MAYBE_MSG_NOSIGNAL))

/**

 * MHD_recv_ is wrapper for system's recv()

 * @param s the socket to use

 * @param b the buffer for data to receive

 * @param l the length of @a b

 * @return ssize_t type value

 */

#define MHD_recv_(s,b,l) \

  ((ssize_t)recv((s),(void*)(b),((MHD_SCKT_SEND_SIZE_)l), 0))

/**

 * Check whether FD can be added to fd_set with specified FD_SETSIZE.

 * @param fd   the fd to check

 * @param pset the pointer to fd_set to check or NULL to check

 *             whether FD can be used with fd_sets.

 * @param setsize the value of FD_SETSIZE.

 * @return boolean true if FD can be added to fd_set,

 *         boolean false otherwise.

 */

#if defined(MHD_POSIX_SOCKETS)

#  define MHD_SCKT_FD_FITS_FDSET_SETSIZE_(fd,pset,setsize) ((fd) < ((MHD_socket)setsize))

#elif defined(MHD_WINSOCK_SOCKETS)

#  define MHD_SCKT_FD_FITS_FDSET_SETSIZE_(fd,pset,setsize) ( ((void*)(pset)==(void*)0) || \

                                                             (((fd_set*)(pset))->fd_count < ((unsigned)setsize)) || \

                                                             (FD_ISSET((fd),(pset))) )

#endif

/**

 * Check whether FD can be added to fd_set with current FD_SETSIZE.

 * @param fd   the fd to check

 * @param pset the pointer to fd_set to check or NULL to check

 *             whether FD can be used with fd_sets.

 * @return boolean true if FD can be added to fd_set,

 *         boolean false otherwise.

 */

#define MHD_SCKT_FD_FITS_FDSET_(fd,pset) MHD_SCKT_FD_FITS_FDSET_SETSIZE_((fd),(pset),FD_SETSIZE)

/**

 * Add FD to fd_set with specified FD_SETSIZE.

 * @param fd   the fd to add

 * @param pset the valid pointer to fd_set.

 * @param setsize the value of FD_SETSIZE.

 * @note  To work on W32 with value of FD_SETSIZE different from currently defined value,

 *        system definition of FD_SET() is not used.

 */

#if defined(MHD_POSIX_SOCKETS)

#  define MHD_SCKT_ADD_FD_TO_FDSET_SETSIZE_(fd,pset,setsize) FD_SET((fd),(pset))

#elif defined(MHD_WINSOCK_SOCKETS)

#  define MHD_SCKT_ADD_FD_TO_FDSET_SETSIZE_(fd,pset,setsize)                     \

        do {                                                                     \

           u_int _i_ = 0;                                                        \

           fd_set* const _s_ = (fd_set*)(pset);                                  \

           while((_i_ < _s_->fd_count) && ((fd) != _s_->fd_array[_i_])) {++_i_;} \

           if ((_i_ == _s_->fd_count)) {_s_->fd_array[_s_->fd_count++] = (fd);}  \

        } while(0)

#endif

 /* MHD_SYS_select_ is wrapper macro for system select() function */

#if !defined(MHD_WINSOCK_SOCKETS)

#  define MHD_SYS_select_(n,r,w,e,t) select((n),(r),(w),(e),(t))

#else

#  define MHD_SYS_select_(n,r,w,e,t) \

( ( (((void*)(r) == (void*)0) || ((fd_set*)(r))->fd_count == 0) &&  \

    (((void*)(w) == (void*)0) || ((fd_set*)(w))->fd_count == 0) &&  \

    (((void*)(e) == (void*)0) || ((fd_set*)(e))->fd_count == 0) ) ? \

  ( ((void*)(t) == (void*)0) ? 0 :                                  \

    (Sleep(((struct timeval*)(t))->tv_sec * 1000 +                  \

           ((struct timeval*)(t))->tv_usec / 1000), 0) ) :          \

  (select((int)0,(r),(w),(e),(t))) )

#endif

#if defined(HAVE_POLL)

/* MHD_sys_poll_ is wrapper macro for system poll() function */

#  if !defined(MHD_WINSOCK_SOCKETS)

#    define MHD_sys_poll_ poll

#  else  /* MHD_WINSOCK_SOCKETS */

#    define MHD_sys_poll_ WSAPoll

#  endif /* MHD_WINSOCK_SOCKETS */

#  ifdef POLLPRI

#    define MHD_POLLPRI_OR_ZERO POLLPRI

#  else  /* ! POLLPRI */

#    define MHD_POLLPRI_OR_ZERO 0

#  endif /* ! POLLPRI */

#  ifdef POLLRDBAND

#    define MHD_POLLRDBAND_OR_ZERO POLLRDBAND

#  else  /* ! POLLRDBAND */

#    define MHD_POLLRDBAND_OR_ZERO 0

#  endif /* ! POLLRDBAND */

#  ifdef POLLNVAL

#    define MHD_POLLNVAL_OR_ZERO POLLNVAL

#  else  /* ! POLLNVAL */

#    define MHD_POLLNVAL_OR_ZERO 0

#  endif /* ! POLLNVAL */

/* MHD_POLL_EVENTS_ERR_DISC is 'events' mask for errors and disconnect.

 * Note: Out-of-band data is treated as error. */

#  if defined(_WIN32) && ! defined(__CYGWIN__)

#    define MHD_POLL_EVENTS_ERR_DISC POLLRDBAND

#  elif defined(__linux__)

#    define MHD_POLL_EVENTS_ERR_DISC POLLPRI

#  else /* ! __linux__ */

#    define MHD_POLL_EVENTS_ERR_DISC (MHD_POLLPRI_OR_ZERO | MHD_POLLRDBAND_OR_ZERO)

#  endif /* ! __linux__ */

/* MHD_POLL_REVENTS_ERR_DISC is 'revents' mask for errors and disconnect.

 * Note: Out-of-band data is treated as error. */

#  define MHD_POLL_REVENTS_ERR_DISC \

     (MHD_POLLPRI_OR_ZERO | MHD_POLLRDBAND_OR_ZERO | MHD_POLLNVAL_OR_ZERO | POLLERR | POLLHUP)

/* MHD_POLL_REVENTS_ERRROR is 'revents' mask for errors.

 * Note: Out-of-band data is treated as error. */

#  define MHD_POLL_REVENTS_ERRROR \

     (MHD_POLLPRI_OR_ZERO | MHD_POLLRDBAND_OR_ZERO | MHD_POLLNVAL_OR_ZERO | POLLERR)

#endif /* HAVE_POLL */

#define MHD_SCKT_MISSING_ERR_CODE_ 31450

#if defined(MHD_POSIX_SOCKETS)

#  if defined(EAGAIN)

#    define MHD_SCKT_EAGAIN_      EAGAIN

#  elif defined(EWOULDBLOCK)

#    define MHD_SCKT_EAGAIN_      EWOULDBLOCK

#  else  /* !EAGAIN && !EWOULDBLOCK */

#    define MHD_SCKT_EAGAIN_      MHD_SCKT_MISSING_ERR_CODE_

#  endif /* !EAGAIN && !EWOULDBLOCK */

#  if defined(EWOULDBLOCK)

#    define MHD_SCKT_EWOULDBLOCK_ EWOULDBLOCK

#  elif defined(EAGAIN)

#    define MHD_SCKT_EWOULDBLOCK_ EAGAIN

#  else  /* !EWOULDBLOCK && !EAGAIN */

#    define MHD_SCKT_EWOULDBLOCK_ MHD_SCKT_MISSING_ERR_CODE_

#  endif /* !EWOULDBLOCK && !EAGAIN */

#  ifdef EINTR

#    define MHD_SCKT_EINTR_       EINTR

#  else  /* ! EINTR */

#    define MHD_SCKT_EINTR_       MHD_SCKT_MISSING_ERR_CODE_

#  endif /* ! EINTR */

#  ifdef ECONNRESET

#    define MHD_SCKT_ECONNRESET_  ECONNRESET

#  else  /* ! ECONNRESET */

#    define MHD_SCKT_ECONNRESET_  MHD_SCKT_MISSING_ERR_CODE_

#  endif /* ! ECONNRESET */

#  ifdef ECONNABORTED

#    define MHD_SCKT_ECONNABORTED_  ECONNABORTED

#  else  /* ! ECONNABORTED */

#    define MHD_SCKT_ECONNABORTED_  MHD_SCKT_MISSING_ERR_CODE_

#  endif /* ! ECONNABORTED */

#  ifdef ENOTCONN

#    define MHD_SCKT_ENOTCONN_    ENOTCONN

#  else  /* ! ENOTCONN */

#    define MHD_SCKT_ENOTCONN_    MHD_SCKT_MISSING_ERR_CODE_

#  endif /* ! ENOTCONN */

#  ifdef EMFILE

#    define MHD_SCKT_EMFILE_      EMFILE

#  else  /* ! EMFILE */

#    define MHD_SCKT_EMFILE_      MHD_SCKT_MISSING_ERR_CODE_

#  endif /* ! EMFILE */

#  ifdef ENFILE

#    define MHD_SCKT_ENFILE_      ENFILE

#  else  /* ! ENFILE */

#    define MHD_SCKT_ENFILE_      MHD_SCKT_MISSING_ERR_CODE_

#  endif /* ! ENFILE */

#  ifdef ENOMEM

#    define MHD_SCKT_ENOMEM_      ENOMEM

#  else  /* ! ENOMEM */

#    define MHD_SCKT_ENOMEM_      MHD_SCKT_MISSING_ERR_CODE_

#  endif /* ! ENOMEM */

#  ifdef ENOBUFS

#    define MHD_SCKT_ENOBUFS_     ENOBUFS

#  else  /* ! ENOBUFS */

#    define MHD_SCKT_ENOBUFS_     MHD_SCKT_MISSING_ERR_CODE_

#  endif /* ! ENOBUFS */

#  ifdef EBADF

#    define MHD_SCKT_EBADF_       EBADF

#  else  /* ! EBADF */

#    define MHD_SCKT_EBADF_       MHD_SCKT_MISSING_ERR_CODE_

#  endif /* ! EBADF */

#  ifdef ENOTSOCK

#    define MHD_SCKT_ENOTSOCK_    ENOTSOCK

#  else  /* ! ENOTSOCK */

#    define MHD_SCKT_ENOTSOCK_    MHD_SCKT_MISSING_ERR_CODE_

#  endif /* ! ENOTSOCK */

#  ifdef EINVAL

#    define MHD_SCKT_EINVAL_      EINVAL

#  else  /* ! EINVAL */

#    define MHD_SCKT_EINVAL_      MHD_SCKT_MISSING_ERR_CODE_

#  endif /* ! EINVAL */

#  ifdef EFAULT

#    define MHD_SCKT_EFAUL_       EFAULT

#  else  /* ! EFAULT */

#    define MHD_SCKT_EFAUL_       MHD_SCKT_MISSING_ERR_CODE_

#  endif /* ! EFAULT */

#  ifdef ENOSYS

#    define MHD_SCKT_ENOSYS_      ENOSYS

#  else  /* ! ENOSYS */

#    define MHD_SCKT_ENOSYS_      MHD_SCKT_MISSING_ERR_CODE_

#  endif /* ! ENOSYS */

#  ifdef ENOTSUP

#    define MHD_SCKT_ENOTSUP_     ENOTSUP

#  else  /* ! ENOTSUP */

#    define MHD_SCKT_ENOTSUP_     MHD_SCKT_MISSING_ERR_CODE_

#  endif /* ! ENOTSUP */

#  ifdef EOPNOTSUPP

#    define MHD_SCKT_EOPNOTSUPP_  EOPNOTSUPP

#  else  /* ! EOPNOTSUPP */

#    define MHD_SCKT_EOPNOTSUPP_  MHD_SCKT_MISSING_ERR_CODE_

#  endif /* ! EOPNOTSUPP */

#  ifdef EACCES

#    define MHD_SCKT_EACCESS_     EACCES

#  else  /* ! EACCES */

#    define MHD_SCKT_EACCESS_     MHD_SCKT_MISSING_ERR_CODE_

#  endif /* ! EACCES */

#  ifdef ENETDOWN

#    define MHD_SCKT_ENETDOWN_    ENETDOWN

#  else  /* ! ENETDOWN */

#    define MHD_SCKT_ENETDOWN_    MHD_SCKT_MISSING_ERR_CODE_

#  endif /* ! ENETDOWN */

#elif defined(MHD_WINSOCK_SOCKETS)

#  define MHD_SCKT_EAGAIN_        WSAEWOULDBLOCK

#  define MHD_SCKT_EWOULDBLOCK_   WSAEWOULDBLOCK

#  define MHD_SCKT_EINTR_         WSAEINTR

#  define MHD_SCKT_ECONNRESET_    WSAECONNRESET

#  define MHD_SCKT_ECONNABORTED_  WSAECONNABORTED

#  define MHD_SCKT_ENOTCONN_      WSAENOTCONN

#  define MHD_SCKT_EMFILE_        WSAEMFILE

#  define MHD_SCKT_ENFILE_        MHD_SCKT_MISSING_ERR_CODE_

#  define MHD_SCKT_ENOMEM_        MHD_SCKT_MISSING_ERR_CODE_

#  define MHD_SCKT_ENOBUFS_       WSAENOBUFS

#  define MHD_SCKT_EBADF_         WSAEBADF

#  define MHD_SCKT_ENOTSOCK_      WSAENOTSOCK

#  define MHD_SCKT_EINVAL_        WSAEINVAL

#  define MHD_SCKT_EFAUL_         WSAEFAULT

#  define MHD_SCKT_ENOSYS_        MHD_SCKT_MISSING_ERR_CODE_

#  define MHD_SCKT_ENOTSUP_       MHD_SCKT_MISSING_ERR_CODE_

#  define MHD_SCKT_EOPNOTSUPP_    WSAEOPNOTSUPP

#  define MHD_SCKT_EACCESS_       WSAEACCES

#  define MHD_SCKT_ENETDOWN_      WSAENETDOWN

#endif

/**

 * MHD_socket_error_ return system native error code for last socket error.

 * @return system error code for last socket error.

 */

#if defined(MHD_POSIX_SOCKETS)

#  define MHD_socket_get_error_() (errno)

#elif defined(MHD_WINSOCK_SOCKETS)

#  define MHD_socket_get_error_() WSAGetLastError()

#endif

#ifdef MHD_WINSOCK_SOCKETS

  /* POSIX-W32 sockets compatibility functions */

/**

 * Return pointer to string description of specified WinSock error

 * @param err the WinSock error code.

 * @return pointer to string description of specified WinSock error.

 */

  const char* MHD_W32_strerror_winsock_(int err);

#endif /* MHD_WINSOCK_SOCKETS */

/* MHD_socket_last_strerr_ is description string of specified socket error code */

#if defined(MHD_POSIX_SOCKETS)

#  define MHD_socket_strerr_(err) strerror((err))

#elif defined(MHD_WINSOCK_SOCKETS)

#  define MHD_socket_strerr_(err) MHD_W32_strerror_winsock_((err))

#endif

/* MHD_socket_last_strerr_ is description string of last errno (non-W32) /

 *                            description string of last socket error (W32) */

#define MHD_socket_last_strerr_() MHD_socket_strerr_(MHD_socket_get_error_())

/**

 * MHD_socket_fset_error_() set socket system native error code.

 */

#if defined(MHD_POSIX_SOCKETS)

#  define MHD_socket_fset_error_(err) (errno = (err))

#elif defined(MHD_WINSOCK_SOCKETS)

#  define MHD_socket_fset_error_(err) (WSASetLastError((err)))

#endif

/**

 * MHD_socket_try_set_error_() set socket system native error code if

 * specified code is defined on system.

 * @return non-zero if specified @a err code is defined on system

 *         and error was set;

 *         zero if specified @a err code is not defined on system

 *         and error was not set.

 */

#define MHD_socket_try_set_error_(err) ( (MHD_SCKT_MISSING_ERR_CODE_ != (err)) ? \

                                         (MHD_socket_fset_error_((err)), !0) : 0 )

/**

 * MHD_socket_set_error_() set socket system native error code to

 * specified code or replacement code if specified code is not

 * defined on system.

 */

#if defined(MHD_POSIX_SOCKETS)

#  if defined(ENOSYS)

#    define MHD_socket_set_error_(err) ( (MHD_SCKT_MISSING_ERR_CODE_ == (err)) ? \

                                         (errno = ENOSYS) : (errno = (err)) )

#  elif defined(EOPNOTSUPP)

#    define MHD_socket_set_error_(err) ( (MHD_SCKT_MISSING_ERR_CODE_ == (err)) ? \

                                         (errno = EOPNOTSUPP) : (errno = (err)) )

#  elif defined (EFAULT)

#    define MHD_socket_set_error_(err) ( (MHD_SCKT_MISSING_ERR_CODE_ == (err)) ? \

                                         (errno = EFAULT) : (errno = (err)) )

#  elif defined (EINVAL)

#    define MHD_socket_set_error_(err) ( (MHD_SCKT_MISSING_ERR_CODE_ == (err)) ? \

                                         (errno = EINVAL) : (errno = (err)) )

#  else  /* !EOPNOTSUPP && !EFAULT && !EINVAL */

#    warning No suitable replacement for missing socket error code is found. Edit this file and add replacement code which is defined on system.

#    define MHD_socket_set_error_(err) (errno = (err))

#  endif /* !EOPNOTSUPP && !EFAULT && !EINVAL*/

#elif defined(MHD_WINSOCK_SOCKETS)

#  define MHD_socket_set_error_(err) ( (MHD_SCKT_MISSING_ERR_CODE_ == (err)) ? \

                                       (WSASetLastError((WSAEOPNOTSUPP))) : \

                                       (WSASetLastError((err))) )

#endif

/**

 * Check whether given socket error is equal to specified system

 * native MHD_SCKT_E*_ code.

 * If platform don't have specific error code, result is

 * always boolean false.

 * @return boolean true if @a code is real error code and

 *         @a err equals to MHD_SCKT_E*_ @a code;

 *         boolean false otherwise

 */

#define MHD_SCKT_ERR_IS_(err,code) ( (MHD_SCKT_MISSING_ERR_CODE_ != (code)) && \

                                     ((code) == (err)) )

/**

 * Check whether last socket error is equal to specified system

 * native MHD_SCKT_E*_ code.

 * If platform don't have specific error code, result is

 * always boolean false.

 * @return boolean true if @a code is real error code and

 *         last socket error equals to MHD_SCKT_E*_ @a code;

 *         boolean false otherwise

 */

#define MHD_SCKT_LAST_ERR_IS_(code) MHD_SCKT_ERR_IS_(MHD_socket_get_error_() ,(code))

/* Specific error code checks */

/**

 * Check whether given socket error is equal to system's

 * socket error codes for EINTR.

 * @return boolean true if @a err is equal to sockets' EINTR code;

 *         boolean false otherwise.

 */

#define MHD_SCKT_ERR_IS_EINTR_(err) MHD_SCKT_ERR_IS_((err),MHD_SCKT_EINTR_)

/**

 * Check whether given socket error is equal to system's

 * socket error codes for EAGAIN or EWOULDBLOCK.

 * @return boolean true if @a err is equal to sockets' EAGAIN or EWOULDBLOCK codes;

 *         boolean false otherwise.

 */

#if MHD_SCKT_EAGAIN_ == MHD_SCKT_EWOULDBLOCK_

#  define MHD_SCKT_ERR_IS_EAGAIN_(err) MHD_SCKT_ERR_IS_((err),MHD_SCKT_EAGAIN_)

#else  /* MHD_SCKT_EAGAIN_ != MHD_SCKT_EWOULDBLOCK_ */

#  define MHD_SCKT_ERR_IS_EAGAIN_(err) ( MHD_SCKT_ERR_IS_((err),MHD_SCKT_EAGAIN_) || \

                                         MHD_SCKT_ERR_IS_((err),MHD_SCKT_EWOULDBLOCK_) )

#endif /* MHD_SCKT_EAGAIN_ != MHD_SCKT_EWOULDBLOCK_ */

/**

 * Check whether given socket error is any kind of "low resource" error.

 * @return boolean true if @a err is any kind of "low resource" error,

 *         boolean false otherwise.

 */

#define MHD_SCKT_ERR_IS_LOW_RESOURCES_(err) ( MHD_SCKT_ERR_IS_((err),MHD_SCKT_EMFILE_) || \

                                              MHD_SCKT_ERR_IS_((err),MHD_SCKT_ENFILE_) || \

                                              MHD_SCKT_ERR_IS_((err),MHD_SCKT_ENOMEM_) || \

                                              MHD_SCKT_ERR_IS_((err),MHD_SCKT_ENOBUFS_) )

/**

 * Check whether is given socket error is type of "incoming connection

 * was disconnected before 'accept()' is called".

 * @return boolean true is @a err match described socket error code,

 *         boolean false otherwise.

 */

#if defined(MHD_POSIX_SOCKETS)

#  define MHD_SCKT_ERR_IS_DISCNN_BEFORE_ACCEPT_(err) MHD_SCKT_ERR_IS_((err),MHD_SCKT_ECONNABORTED_)

#elif defined(MHD_WINSOCK_SOCKETS)

#  define MHD_SCKT_ERR_IS_DISCNN_BEFORE_ACCEPT_(err) MHD_SCKT_ERR_IS_((err),MHD_SCKT_ECONNRESET_)

#endif

/**

 * Check whether is given socket error is type of "connection was terminated

 * by remote side".

 * @return boolean true is @a err match described socket error code,

 *         boolean false otherwise.

 */

#define MHD_SCKT_ERR_IS_REMOTE_DISCNN_(err) ( MHD_SCKT_ERR_IS_((err),MHD_SCKT_ECONNRESET_) || \

                                              MHD_SCKT_ERR_IS_((err),MHD_SCKT_ECONNABORTED_))

/* Specific error code set */

/**

 * Set socket's error code to ENOMEM or equivalent if ENOMEM is not

 * available on platform.

 */

#if MHD_SCKT_MISSING_ERR_CODE_ != MHD_SCKT_ENOMEM_

#  define MHD_socket_set_error_to_ENOMEM() MHD_socket_set_error_(MHD_SCKT_ENOMEM_)

#elif MHD_SCKT_MISSING_ERR_CODE_ != MHD_SCKT_ENOBUFS_

#  define MHD_socket_set_error_to_ENOMEM() MHD_socket_set_error_(MHD_SCKT_ENOBUFS_)

#else

#  warning No suitable replacement for ENOMEM error codes is found. Edit this file and add replacement code which is defined on system.

#  define MHD_socket_set_error_to_ENOMEM() MHD_socket_set_error_(MHD_SCKT_ENOMEM_)

#endif

/* Socket functions */

#if defined(AF_LOCAL)

#  define MHD_SCKT_LOCAL AF_LOCAL

#elif defined(AF_UNIX)

#  define MHD_SCKT_LOCAL AF_UNIX

#endif /* AF_UNIX */

#if defined(MHD_POSIX_SOCKETS) && defined(MHD_SCKT_LOCAL)

#  define MHD_socket_pair_(fdarr) (!socketpair(MHD_SCKT_LOCAL, SOCK_STREAM, 0, (fdarr)))

#  if defined(HAVE_SOCK_NONBLOCK)

#    define MHD_socket_pair_nblk_(fdarr) (!socketpair(MHD_SCKT_LOCAL, SOCK_STREAM | SOCK_NONBLOCK, 0, (fdarr)))

#  endif /* HAVE_SOCK_NONBLOCK*/

#elif defined(MHD_WINSOCK_SOCKETS)

   /**

    * Create pair of mutually connected TCP/IP sockets on loopback address

    * @param sockets_pair array to receive resulted sockets

    * @param non_blk if set to non-zero value, sockets created in non-blocking mode

    *                otherwise sockets will be in blocking mode

    * @return non-zero if succeeded, zero otherwise

    */

   int MHD_W32_socket_pair_(SOCKET sockets_pair[2], int non_blk);

#  define MHD_socket_pair_(fdarr) MHD_W32_socket_pair_((fdarr), 0)

#  define MHD_socket_pair_nblk_(fdarr) MHD_W32_socket_pair_((fdarr), 1)

#endif

/**

 * Add @a fd to the @a set.  If @a fd is

 * greater than @a max_fd, set @a max_fd to @a fd.

 *

 * @param fd file descriptor to add to the @a set

 * @param set set to modify

 * @param max_fd maximum value to potentially update

 * @param fd_setsize value of FD_SETSIZE

 * @return non-zero if succeeded, zero otherwise

 */

int

MHD_add_to_fd_set_ (MHD_socket fd,

                    fd_set *set,

                    MHD_socket *max_fd,

                    unsigned int fd_setsize);

/**

 * Change socket options to be non-blocking.

 *

 * @param sock socket to manipulate

 * @return non-zero if succeeded, zero otherwise

 */

int

MHD_socket_nonblocking_ (MHD_socket sock);

/**

 * Change socket options to be non-inheritable.

 *

 * @param sock socket to manipulate

 * @return non-zero if succeeded, zero otherwise

 * @warning Does not set socket error on W32.

 */

int

MHD_socket_noninheritable_ (MHD_socket sock);

#if defined(SOL_SOCKET) && defined(SO_NOSIGPIPE)

   static const int _MHD_socket_int_one = 1;

/**

 * Change socket options to no signal on remote disconnect.

 *

 * @param sock socket to manipulate

 * @return non-zero if succeeded, zero otherwise

 */

#  define MHD_socket_nosignal_(sock) \

    (!setsockopt((sock),SOL_SOCKET,SO_NOSIGPIPE,&_MHD_socket_int_one,sizeof(_MHD_socket_int_one)))

#endif /* SOL_SOCKET && SO_NOSIGPIPE */

/**

 * Create a listen socket, with noninheritable flag if possible.

 *

 * @param use_ipv6 if set to non-zero IPv6 is used

 * @return created socket or MHD_INVALID_SOCKET in case of errors

 */

MHD_socket

MHD_socket_create_listen_ (int use_ipv6);

#endif /* ! MHD_SOCKETS_H */