/* strerror_r.c --- POSIX compatible system error routine

   Copyright (C) 2010-2011 Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program 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 General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

/* Written by Bruno Haible <bruno@clisp.org>, 2010.  */

#include <config.h>

/* Enable declaration of sys_nerr and sys_errlist in <errno.h> on NetBSD.  */
#define _NETBSD_SOURCE 1

/* Specification.  */
#include <string.h>

#include <errno.h>

# if GNULIB_defined_ESOCK /* native Windows platforms */
#  if HAVE_WINSOCK2_H
#   include <winsock2.h>
#  endif
# endif


#if (__GLIBC__ >= 2 || defined __UCLIBC__ || defined __CYGWIN__) && HAVE___XPG_STRERROR_R /* glibc >= 2.3.4, cygwin >= 1.7.9 */

# define USE_XPG_STRERROR_R 1

#elif HAVE_DECL_STRERROR_R && !(__GLIBC__ >= 2 || defined __UCLIBC__)

/* The system's strerror_r function is OK, except that its third argument
   is 'int', not 'size_t', or its return type is wrong.  */

# include <limits.h>

# define USE_SYSTEM_STRERROR_R 1

#else /* (__GLIBC__ >= 2 || defined __UCLIBC__ ? !HAVE___XPG_STRERROR_R : !HAVE_DECL_STRERROR_R) */

/* Use the system's strerror().  */
# undef strerror

# define USE_SYSTEM_STRERROR 1

# if defined __NetBSD__ || defined __hpux || ((defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__) || defined __sgi || (defined __sun && !defined _LP64)

/* No locking needed.  */

/* Get catgets internationalization functions.  */
#  if HAVE_CATGETS
#   include <nl_types.h>
#  endif

/* Get sys_nerr, sys_errlist on HP-UX (otherwise only declared in C++ mode).
   Get sys_nerr, sys_errlist on IRIX (otherwise only declared with _SGIAPI).  */
#  if defined __hpux || defined __sgi
extern int sys_nerr;
extern char *sys_errlist[];
#  endif

/* Get sys_nerr on Solaris.  */
#  if defined __sun && !defined _LP64
extern int sys_nerr;
#  endif

/* Get sys_nerr, sys_errlist on native Windows.  */
#  include <stdlib.h>

# else

#  include "glthread/lock.h"

/* This lock protects the buffer returned by strerror().  We assume that
   no other uses of strerror() exist in the program.  */
gl_lock_define_initialized(static, strerror_lock)

# endif

#endif


int
strerror_r (int errnum, char *buf, size_t buflen)
#undef strerror_r
{
#if GNULIB_defined_ETXTBSY \
    || GNULIB_defined_ESOCK \
    || GNULIB_defined_ENOMSG \
    || GNULIB_defined_EIDRM \
    || GNULIB_defined_ENOLINK \
    || GNULIB_defined_EPROTO \
    || GNULIB_defined_EMULTIHOP \
    || GNULIB_defined_EBADMSG \
    || GNULIB_defined_EOVERFLOW \
    || GNULIB_defined_ENOTSUP \
    || GNULIB_defined_ESTALE \
    || GNULIB_defined_EDQUOT \
    || GNULIB_defined_ECANCELED
  {
    char const *msg = NULL;
    /* These error messages are taken from glibc/sysdeps/gnu/errlist.c.  */
    switch (errnum)
      {
# if GNULIB_defined_ETXTBSY
      case ETXTBSY:
        msg = "Text file busy";
        break;
# endif

# if GNULIB_defined_ESOCK /* native Windows platforms */
      /* EWOULDBLOCK is the same as EAGAIN.  */
      case EINPROGRESS:
        msg = "Operation now in progress";
        break;
      case EALREADY:
        msg = "Operation already in progress";
        break;
      case ENOTSOCK:
        msg = "Socket operation on non-socket";
        break;
      case EDESTADDRREQ:
        msg = "Destination address required";
        break;
      case EMSGSIZE:
        msg = "Message too long";
        break;
      case EPROTOTYPE:
        msg = "Protocol wrong type for socket";
        break;
      case ENOPROTOOPT:
        msg = "Protocol not available";
        break;
      case EPROTONOSUPPORT:
        msg = "Protocol not supported";
        break;
      case ESOCKTNOSUPPORT:
        msg = "Socket type not supported";
        break;
      case EOPNOTSUPP:
        msg = "Operation not supported";
        break;
      case EPFNOSUPPORT:
        msg = "Protocol family not supported";
        break;
      case EAFNOSUPPORT:
        msg = "Address family not supported by protocol";
        break;
      case EADDRINUSE:
        msg = "Address already in use";
        break;
      case EADDRNOTAVAIL:
        msg = "Cannot assign requested address";
        break;
      case ENETDOWN:
        msg = "Network is down";
        break;
      case ENETUNREACH:
        msg = "Network is unreachable";
        break;
      case ENETRESET:
        msg = "Network dropped connection on reset";
        break;
      case ECONNABORTED:
        msg = "Software caused connection abort";
        break;
      case ECONNRESET:
        msg = "Connection reset by peer";
        break;
      case ENOBUFS:
        msg = "No buffer space available";
        break;
      case EISCONN:
        msg = "Transport endpoint is already connected";
        break;
      case ENOTCONN:
        msg = "Transport endpoint is not connected";
        break;
      case ESHUTDOWN:
        msg = "Cannot send after transport endpoint shutdown";
        break;
      case ETOOMANYREFS:
        msg = "Too many references: cannot splice";
        break;
      case ETIMEDOUT:
        msg = "Connection timed out";
        break;
      case ECONNREFUSED:
        msg = "Connection refused";
        break;
      case ELOOP:
        msg = "Too many levels of symbolic links";
        break;
      case EHOSTDOWN:
        msg = "Host is down";
        break;
      case EHOSTUNREACH:
        msg = "No route to host";
        break;
      case EPROCLIM:
        msg = "Too many processes";
        break;
      case EUSERS:
        msg = "Too many users";
        break;
      case EDQUOT:
        msg = "Disk quota exceeded";
        break;
      case ESTALE:
        msg = "Stale NFS file handle";
        break;
      case EREMOTE:
        msg = "Object is remote";
        break;
#  if HAVE_WINSOCK2_H
      /* WSA_INVALID_HANDLE maps to EBADF */
      /* WSA_NOT_ENOUGH_MEMORY maps to ENOMEM */
      /* WSA_INVALID_PARAMETER maps to EINVAL */
      case WSA_OPERATION_ABORTED:
        msg = "Overlapped operation aborted";
        break;
      case WSA_IO_INCOMPLETE:
        msg = "Overlapped I/O event object not in signaled state";
        break;
      case WSA_IO_PENDING:
        msg = "Overlapped operations will complete later";
        break;
      /* WSAEINTR maps to EINTR */
      /* WSAEBADF maps to EBADF */
      /* WSAEACCES maps to EACCES */
      /* WSAEFAULT maps to EFAULT */
      /* WSAEINVAL maps to EINVAL */
      /* WSAEMFILE maps to EMFILE */
      /* WSAEWOULDBLOCK maps to EWOULDBLOCK */
      /* WSAEINPROGRESS is EINPROGRESS */
      /* WSAEALREADY is EALREADY */
      /* WSAENOTSOCK is ENOTSOCK */
      /* WSAEDESTADDRREQ is EDESTADDRREQ */
      /* WSAEMSGSIZE is EMSGSIZE */
      /* WSAEPROTOTYPE is EPROTOTYPE */
      /* WSAENOPROTOOPT is ENOPROTOOPT */
      /* WSAEPROTONOSUPPORT is EPROTONOSUPPORT */
      /* WSAESOCKTNOSUPPORT is ESOCKTNOSUPPORT */
      /* WSAEOPNOTSUPP is EOPNOTSUPP */
      /* WSAEPFNOSUPPORT is EPFNOSUPPORT */
      /* WSAEAFNOSUPPORT is EAFNOSUPPORT */
      /* WSAEADDRINUSE is EADDRINUSE */
      /* WSAEADDRNOTAVAIL is EADDRNOTAVAIL */
      /* WSAENETDOWN is ENETDOWN */
      /* WSAENETUNREACH is ENETUNREACH */
      /* WSAENETRESET is ENETRESET */
      /* WSAECONNABORTED is ECONNABORTED */
      /* WSAECONNRESET is ECONNRESET */
      /* WSAENOBUFS is ENOBUFS */
      /* WSAEISCONN is EISCONN */
      /* WSAENOTCONN is ENOTCONN */
      /* WSAESHUTDOWN is ESHUTDOWN */
      /* WSAETOOMANYREFS is ETOOMANYREFS */
      /* WSAETIMEDOUT is ETIMEDOUT */
      /* WSAECONNREFUSED is ECONNREFUSED */
      /* WSAELOOP is ELOOP */
      /* WSAENAMETOOLONG maps to ENAMETOOLONG */
      /* WSAEHOSTDOWN is EHOSTDOWN */
      /* WSAEHOSTUNREACH is EHOSTUNREACH */
      /* WSAENOTEMPTY maps to ENOTEMPTY */
      /* WSAEPROCLIM is EPROCLIM */
      /* WSAEUSERS is EUSERS */
      /* WSAEDQUOT is EDQUOT */
      /* WSAESTALE is ESTALE */
      /* WSAEREMOTE is EREMOTE */
      case WSASYSNOTREADY:
        msg = "Network subsystem is unavailable";
        break;
      case WSAVERNOTSUPPORTED:
        msg = "Winsock.dll version out of range";
        break;
      case WSANOTINITIALISED:
        msg = "Successful WSAStartup not yet performed";
        break;
      case WSAEDISCON:
        msg = "Graceful shutdown in progress";
        break;
      case WSAENOMORE: case WSA_E_NO_MORE:
        msg = "No more results";
        break;
      case WSAECANCELLED: case WSA_E_CANCELLED:
        msg = "Call was canceled";
        break;
      case WSAEINVALIDPROCTABLE:
        msg = "Procedure call table is invalid";
        break;
      case WSAEINVALIDPROVIDER:
        msg = "Service provider is invalid";
        break;
      case WSAEPROVIDERFAILEDINIT:
        msg = "Service provider failed to initialize";
        break;
      case WSASYSCALLFAILURE:
        msg = "System call failure";
        break;
      case WSASERVICE_NOT_FOUND:
        msg = "Service not found";
        break;
      case WSATYPE_NOT_FOUND:
        msg = "Class type not found";
        break;
      case WSAEREFUSED:
        msg = "Database query was refused";
        break;
      case WSAHOST_NOT_FOUND:
        msg = "Host not found";
        break;
      case WSATRY_AGAIN:
        msg = "Nonauthoritative host not found";
        break;
      case WSANO_RECOVERY:
        msg = "Nonrecoverable error";
        break;
      case WSANO_DATA:
        msg = "Valid name, no data record of requested type";
        break;
      /* WSA_QOS_* omitted */
#  endif
# endif

# if GNULIB_defined_ENOMSG
      case ENOMSG:
        msg = "No message of desired type";
        break;
# endif

# if GNULIB_defined_EIDRM
      case EIDRM:
        msg = "Identifier removed";
        break;
# endif

# if GNULIB_defined_ENOLINK
      case ENOLINK:
        msg = "Link has been severed";
        break;
# endif

# if GNULIB_defined_EPROTO
      case EPROTO:
        msg = "Protocol error";
        break;
# endif

# if GNULIB_defined_EMULTIHOP
      case EMULTIHOP:
        msg = "Multihop attempted";
        break;
# endif

# if GNULIB_defined_EBADMSG
      case EBADMSG:
        msg = "Bad message";
        break;
# endif

# if GNULIB_defined_EOVERFLOW
      case EOVERFLOW:
        msg = "Value too large for defined data type";
        break;
# endif

# if GNULIB_defined_ENOTSUP
      case ENOTSUP:
        msg = "Not supported";
        break;
# endif

# if GNULIB_defined_ESTALE
      case ESTALE:
        msg = "Stale NFS file handle";
        break;
# endif

# if GNULIB_defined_EDQUOT
      case EDQUOT:
        msg = "Disk quota exceeded";
        break;
# endif

# if GNULIB_defined_ECANCELED
      case ECANCELED:
        msg = "Operation canceled";
        break;
# endif
      }

    if (msg)
      {
        int saved_errno = errno;
        size_t len = strlen (msg);
        int ret = ERANGE;

        if (len < buflen)
          {
            memcpy (buf, msg, len + 1);
            ret = 0;
          }
        errno = saved_errno;
        return ret;
      }
  }
#endif

  {
    int ret;
    int saved_errno = errno;

#if USE_XPG_STRERROR_R

    {
      extern int __xpg_strerror_r (int errnum, char *buf, size_t buflen);

      ret = __xpg_strerror_r (errnum, buf, buflen);
      if (ret < 0)
        ret = errno;
    }

#elif USE_SYSTEM_STRERROR_R

    if (buflen > INT_MAX)
      buflen = INT_MAX;

# ifdef __hpux
    /* On HP-UX 11.31, strerror_r always fails when buflen < 80.  */
    {
      char stackbuf[80];

      if (buflen < sizeof (stackbuf))
        {
          ret = strerror_r (errnum, stackbuf, sizeof (stackbuf));
          if (ret == 0)
            {
              size_t len = strlen (stackbuf);

              if (len < buflen)
                memcpy (buf, stackbuf, len + 1);
              else
                ret = ERANGE;
            }
        }
      else
        ret = strerror_r (errnum, buf, buflen);
    }
# elif defined __CYGWIN__
    /* Cygwin 1.7.8 only provides the glibc interface, is thread-safe, and
       always succeeds (although it may truncate). */
    strerror_r (errnum, buf, buflen);
    ret = 0;
# else
    ret = strerror_r (errnum, buf, buflen);
# endif

# ifdef _AIX
    /* On AIX 6.1, strerror_r returns -1 and sets errno to EINVAL
       if buflen <= 1.  */
    if (ret < 0 && errno == EINVAL && buflen <= 1)
      {
        /* Retry with a larger buffer.  */
        char largerbuf[10];
        ret = strerror_r (errnum, largerbuf, sizeof (largerbuf));
        if (ret < 0 && errno == EINVAL)
          {
            /* errnum was out of range.  */
            ret = EINVAL;
          }
        else
          {
            /* buf was too small.  */
            ret = ERANGE;
          }
      }
# endif

    /* Some old implementations may return (-1, EINVAL) instead of EINVAL.  */
    if (ret < 0)
      ret = errno;

    /* FreeBSD rejects 0; see http://austingroupbugs.net/view.php?id=382.  */
    if (errnum == 0 && ret == EINVAL)
      {
        if (buflen <= strlen ("Success"))
          {
            ret = ERANGE;
            if (buflen)
              buf[0] = 0;
          }
        else
          {
            ret = 0;
            strcpy (buf, "Success");
          }
      }

#else /* USE_SYSTEM_STRERROR */

    /* Try to do what strerror (errnum) does, but without clobbering the
       buffer used by strerror().  */

# if defined __NetBSD__ || defined __hpux || ((defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__) /* NetBSD, HP-UX, native Win32 */

    /* NetBSD:        sys_nerr, sys_errlist are declared through _NETBSD_SOURCE
                      and <errno.h> above.
       HP-UX:         sys_nerr, sys_errlist are declared explicitly above.
       native Win32:  sys_nerr, sys_errlist are declared in <stdlib.h>.  */
    if (errnum >= 0 && errnum < sys_nerr)
      {
#  if HAVE_CATGETS && (defined __NetBSD__ || defined __hpux)
#   if defined __NetBSD__
        nl_catd catd = catopen ("libc", NL_CAT_LOCALE);
        const char *errmsg =
          (catd != (nl_catd)-1
           ? catgets (catd, 1, errnum, sys_errlist[errnum])
           : sys_errlist[errnum]);
#   endif
#   if defined __hpux
        nl_catd catd = catopen ("perror", NL_CAT_LOCALE);
        const char *errmsg =
          (catd != (nl_catd)-1
           ? catgets (catd, 1, 1 + errnum, sys_errlist[errnum])
           : sys_errlist[errnum]);
#   endif
#  else
        const char *errmsg = sys_errlist[errnum];
#  endif
        if (errmsg == NULL || *errmsg == '\0')
          ret = EINVAL;
        else
          {
            size_t len = strlen (errmsg);

            if (len < buflen)
              {
                memcpy (buf, errmsg, len + 1);
                ret = 0;
              }
            else
              ret = ERANGE;
          }
#  if HAVE_CATGETS && (defined __NetBSD__ || defined __hpux)
        if (catd != (nl_catd)-1)
          catclose (catd);
#  endif
      }
    else
      ret = EINVAL;

# elif defined __sgi || (defined __sun && !defined _LP64) /* IRIX, Solaris <= 9 32-bit */

    /* For a valid error number, the system's strerror() function returns
       a pointer to a not copied string, not to a buffer.  */
    if (errnum >= 0 && errnum < sys_nerr)
      {
        char *errmsg = strerror (errnum);

        if (errmsg == NULL || *errmsg == '\0')
          ret = EINVAL;
        else
          {
            size_t len = strlen (errmsg);

            if (len < buflen)
              {
                memcpy (buf, errmsg, len + 1);
                ret = 0;
              }
            else
              ret = ERANGE;
          }
      }
    else
      ret = EINVAL;

# else

    gl_lock_lock (strerror_lock);

    {
      char *errmsg = strerror (errnum);

      /* For invalid error numbers, strerror() on
           - IRIX 6.5 returns NULL,
           - HP-UX 11 returns an empty string.  */
      if (errmsg == NULL || *errmsg == '\0')
        ret = EINVAL;
      else
        {
          size_t len = strlen (errmsg);

          if (len < buflen)
            {
              memcpy (buf, errmsg, len + 1);
              ret = 0;
            }
          else
            ret = ERANGE;
        }
    }

    gl_lock_unlock (strerror_lock);

# endif

#endif

    errno = saved_errno;
    return ret;
  }
}