/***************************************************************************

 *                                  _   _ ____  _

 *  Project                     ___| | | |  _ \| |

 *                             / __| | | | |_) | |

 *                            | (__| |_| |  _ <| |___

 *                             \___|\___/|_| \_\_____|

 *

 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.

 *

 * This software is licensed as described in the file COPYING, which

 * you should have received as part of this distribution. The terms

 * are also available at https://curl.se/docs/copyright.html.

 *

 * You may opt to use, copy, modify, merge, publish, distribute and/or sell

 * copies of the Software, and permit persons to whom the Software is

 * furnished to do so, under the terms of the COPYING file.

 *

 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY

 * KIND, either express or implied.

 *

 * SPDX-License-Identifier: curl

 *

 ***************************************************************************/

#include "curl_setup.h"

#ifdef HAVE_STRERROR_R

#  if (!defined(HAVE_POSIX_STRERROR_R) && \

       !defined(HAVE_GLIBC_STRERROR_R)) || \

      (defined(HAVE_POSIX_STRERROR_R) && defined(HAVE_GLIBC_STRERROR_R))

#    error "strerror_r MUST be either POSIX, glibc style"

#  endif

#endif

#include "curlx/winapi.h"

#include "curlx/snprintf.h"

#include "curlx/strerr.h"

#include "curlx/strcopy.h"

#ifdef USE_WINSOCK

/* This is a helper function for curlx_strerror that converts Winsock error

 * codes (WSAGetLastError) to error messages.

 * Returns NULL if no error message was found for error code.

 */

static const char *get_winsock_error(int err, char *buf, size_t len)

{

  VERBOSE(const char *p);

  if(!len)

    return NULL;

  *buf = '\0';

#ifndef CURLVERBOSE

  (void)err;

  return NULL;

#else

  switch(err) {

  case WSAEINTR:

    p = "Call interrupted";

    break;

  case WSAEBADF:

    p = "Bad file";

    break;

  case WSAEACCES:

    p = "Bad access";

    break;

  case WSAEFAULT:

    p = "Bad argument";

    break;

  case WSAEINVAL:

    p = "Invalid arguments";

    break;

  case WSAEMFILE:

    p = "Out of file descriptors";

    break;

  case WSAEWOULDBLOCK:

    p = "Call would block";

    break;

  case WSAEINPROGRESS:

  case WSAEALREADY:

    p = "Blocking call in progress";

    break;

  case WSAENOTSOCK:

    p = "Descriptor is not a socket";

    break;

  case WSAEDESTADDRREQ:

    p = "Need destination address";

    break;

  case WSAEMSGSIZE:

    p = "Bad message size";

    break;

  case WSAEPROTOTYPE:

    p = "Bad protocol";

    break;

  case WSAENOPROTOOPT:

    p = "Protocol option is unsupported";

    break;

  case WSAEPROTONOSUPPORT:

    p = "Protocol is unsupported";

    break;

  case WSAESOCKTNOSUPPORT:

    p = "Socket is unsupported";

    break;

  case WSAEOPNOTSUPP:

    p = "Operation not supported";

    break;

  case WSAEAFNOSUPPORT:

    p = "Address family not supported";

    break;

  case WSAEPFNOSUPPORT:

    p = "Protocol family not supported";

    break;

  case WSAEADDRINUSE:

    p = "Address already in use";

    break;

  case WSAEADDRNOTAVAIL:

    p = "Address not available";

    break;

  case WSAENETDOWN:

    p = "Network down";

    break;

  case WSAENETUNREACH:

    p = "Network unreachable";

    break;

  case WSAENETRESET:

    p = "Network has been reset";

    break;

  case WSAECONNABORTED:

    p = "Connection was aborted";

    break;

  case WSAECONNRESET:

    p = "Connection was reset";

    break;

  case WSAENOBUFS:

    p = "No buffer space";

    break;

  case WSAEISCONN:

    p = "Socket is already connected";

    break;

  case WSAENOTCONN:

    p = "Socket is not connected";

    break;

  case WSAESHUTDOWN:

    p = "Socket has been shut down";

    break;

  case WSAETOOMANYREFS:

    p = "Too many references";

    break;

  case WSAETIMEDOUT:

    p = "Timed out";

    break;

  case WSAECONNREFUSED:

    p = "Connection refused";

    break;

  case WSAELOOP:

    p = "Loop??";

    break;

  case WSAENAMETOOLONG:

    p = "Name too long";

    break;

  case WSAEHOSTDOWN:

    p = "Host down";

    break;

  case WSAEHOSTUNREACH:

    p = "Host unreachable";

    break;

  case WSAENOTEMPTY:

    p = "Not empty";

    break;

  case WSAEPROCLIM:

    p = "Process limit reached";

    break;

  case WSAEUSERS:

    p = "Too many users";

    break;

  case WSAEDQUOT:

    p = "Bad quota";

    break;

  case WSAESTALE:

    p = "Something is stale";

    break;

  case WSAEREMOTE:

    p = "Remote error";

    break;

  case WSAEDISCON:

    p = "Disconnected";

    break;

    /* Extended Winsock errors */

  case WSASYSNOTREADY:

    p = "Winsock library is not ready";

    break;

  case WSANOTINITIALISED:

    p = "Winsock library not initialised";

    break;

  case WSAVERNOTSUPPORTED:

    p = "Winsock version not supported";

    break;

    /* getXbyY() errors (already handled in herrmsg):

     * Authoritative Answer: Host not found */

  case WSAHOST_NOT_FOUND:

    p = "Host not found";

    break;

    /* Non-Authoritative: Host not found, or SERVERFAIL */

  case WSATRY_AGAIN:

    p = "Host not found, try again";

    break;

    /* Non recoverable errors, FORMERR, REFUSED, NOTIMP */

  case WSANO_RECOVERY:

    p = "Unrecoverable error in call to nameserver";

    break;

    /* Valid name, no data record of requested type */

  case WSANO_DATA:

    p = "No data record of requested type";

    break;

  default:

    return NULL;

  }

  curlx_strcopy(buf, len, p, strlen(p));

  return buf;

#endif

}

#endif /* USE_WINSOCK */

/*

 * Our thread-safe and smart strerror() replacement.

 *

 * The 'err' argument passed in to this function MUST be a true errno number

 * as reported on this system. We do no range checking on the number before

 * we pass it to the "number-to-message" conversion function and there might

 * be systems that do not do proper range checking in there themselves.

 *

 * We do not do range checking (on systems other than Windows) since there is

 * no good reliable and portable way to do it.

 *

 * On Windows different types of error codes overlap. This function has an

 * order of preference when trying to match error codes:

 * CRT (errno), Winsock (WSAGetLastError), Windows API (GetLastError).

 *

 * It may be more correct to call one of the variant functions instead:

 * Call Curl_sspi_strerror if the error code is definitely Windows SSPI.

 * Call curlx_winapi_strerror if the error code is definitely Windows API.

 */

const char *curlx_strerror(int err, char *buf, size_t buflen)

{

#ifdef _WIN32

  DWORD old_win_err = GetLastError();

#endif

  int old_errno = errno;

  char *p;

  if(!buflen)

    return NULL;

#ifndef _WIN32

  DEBUGASSERT(err >= 0);

#endif

  *buf = '\0';

#ifdef _WIN32

  if((!strerror_s(buf, buflen, err) || !strcmp(buf, "Unknown error")) &&

#ifdef USE_WINSOCK

     !get_winsock_error(err, buf, buflen) &&

#endif

     !curlx_get_winapi_error((DWORD)err, buf, buflen))

    SNPRINTF(buf, buflen, "Unknown error %d (%#x)", err, err);

#else /* !_WIN32 */

#if defined(HAVE_STRERROR_R) && defined(HAVE_POSIX_STRERROR_R)

  /*

   * The POSIX-style strerror_r() may set errno to ERANGE if insufficient

   * storage is supplied via 'strerrbuf' and 'buflen' to hold the generated

   * message string, or EINVAL if 'errnum' is not a valid error number.

   */

  if(strerror_r(err, buf, buflen) &&

     buflen > sizeof("Unknown error ") + 20) {

    if(buf[0] == '\0')

      SNPRINTF(buf, buflen, "Unknown error %d", err);

  }

#elif defined(HAVE_STRERROR_R) && defined(HAVE_GLIBC_STRERROR_R)

  /*

   * The glibc-style strerror_r() only *might* use the buffer we pass to

   * the function, but it always returns the error message as a pointer,

   * so we must copy that string unconditionally (if non-NULL).

   */

  {

    char buffer[256];

    const char *msg = strerror_r(err, buffer, sizeof(buffer));

    if(msg && buflen > 1)

      SNPRINTF(buf, buflen, "%s", msg);

    else if(buflen > sizeof("Unknown error ") + 20)

      SNPRINTF(buf, buflen, "Unknown error %d", err);

  }

#else

  {

    /* !checksrc! disable BANNEDFUNC 1 */

    const char *msg = strerror(err);

    if(msg && buflen > 1)

      SNPRINTF(buf, buflen, "%s", msg);

    else if(buflen > sizeof("Unknown error ") + 20)

      SNPRINTF(buf, buflen, "Unknown error %d", err);

  }

#endif

#endif /* _WIN32 */

  /* strip trailing '\r\n' or '\n'. */

  p = strrchr(buf, '\n');

  if(p && (p - buf) >= 2)

    *p = '\0';

  p = strrchr(buf, '\r');

  if(p && (p - buf) >= 1)

    *p = '\0';

  if(errno != old_errno)

    errno = old_errno;

#ifdef _WIN32

  if(old_win_err != GetLastError())

    SetLastError(old_win_err);

#endif

  return buf;

}