curl/src/tool_filetime.c

/***************************************************************************
 *                                  _   _ ____  _
 *  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 "tool_filetime.h"
#include "tool_cfgable.h"
#include "tool_msgs.h"
#include "curlx.h"

#ifdef HAVE_UTIME_H
#  include <utime.h>
#elif defined(HAVE_SYS_UTIME_H)
#  include <sys/utime.h>
#endif

/* Returns 0 on success, non-zero on file problems */
int getfiletime(const char *filename, struct GlobalConfig *global,
                curl_off_t *stamp)
{
  int rc = 1;

/* Windows stat() may attempt to adjust the Unix GMT file time by a daylight
   saving time offset and since it is GMT that is bad behavior. When we have
   access to a 64-bit type we can bypass stat and get the times directly. */
#if defined(_WIN32) && !defined(CURL_WINDOWS_UWP)
  HANDLE hfile;
  TCHAR *tchar_filename = curlx_convert_UTF8_to_tchar(filename);

  hfile = CreateFile(tchar_filename, FILE_READ_ATTRIBUTES,
                      (FILE_SHARE_READ | FILE_SHARE_WRITE |
                       FILE_SHARE_DELETE),
                      NULL, OPEN_EXISTING, 0, NULL);
  curlx_unicodefree(tchar_filename);
  if(hfile != INVALID_HANDLE_VALUE) {
    FILETIME ft;
    if(GetFileTime(hfile, NULL, NULL, &ft)) {
      curl_off_t converted = (curl_off_t)ft.dwLowDateTime
        | ((curl_off_t)ft.dwHighDateTime) << 32;

      if(converted < CURL_OFF_T_C(116444736000000000))
        warnf(global, "Failed to get filetime: underflow");
      else {
        *stamp = (converted - CURL_OFF_T_C(116444736000000000)) / 10000000;
        rc = 0;
      }
    }
    else {
      warnf(global, "Failed to get filetime: "
            "GetFileTime failed: GetLastError %u",
            (unsigned int)GetLastError());
    }
    CloseHandle(hfile);
  }
  else if(GetLastError() != ERROR_FILE_NOT_FOUND) {
    warnf(global, "Failed to get filetime: "
          "CreateFile failed: GetLastError %u",
          (unsigned int)GetLastError());
  }
#else
  struct_stat statbuf;
  if(-1 != stat(filename, &statbuf)) {
    *stamp = (curl_off_t)statbuf.st_mtime;
    rc = 0;
  }
  else
    warnf(global, "Failed to get filetime: %s", strerror(errno));
#endif
  return rc;
}

#if defined(HAVE_UTIME) || defined(HAVE_UTIMES) || defined(_WIN32)
void setfiletime(curl_off_t filetime, const char *filename,
                 struct GlobalConfig *global)
{
  if(filetime >= 0) {
/* Windows utime() may attempt to adjust the Unix GMT file time by a daylight
   saving time offset and since it is GMT that is bad behavior. When we have
   access to a 64-bit type we can bypass utime and set the times directly. */
#if defined(_WIN32) && !defined(CURL_WINDOWS_UWP)
    HANDLE hfile;
    TCHAR *tchar_filename = curlx_convert_UTF8_to_tchar(filename);

    /* 910670515199 is the maximum Unix filetime that can be used as a
       Windows FILETIME without overflow: 30827-12-31T23:59:59. */
    if(filetime > CURL_OFF_T_C(910670515199)) {
      warnf(global, "Failed to set filetime %" CURL_FORMAT_CURL_OFF_T
            " on outfile: overflow", filetime);
      curlx_unicodefree(tchar_filename);
      return;
    }

    hfile = CreateFile(tchar_filename, FILE_WRITE_ATTRIBUTES,
                       (FILE_SHARE_READ | FILE_SHARE_WRITE |
                        FILE_SHARE_DELETE),
                       NULL, OPEN_EXISTING, 0, NULL);
    curlx_unicodefree(tchar_filename);
    if(hfile != INVALID_HANDLE_VALUE) {
      curl_off_t converted = ((curl_off_t)filetime * 10000000) +
        CURL_OFF_T_C(116444736000000000);
      FILETIME ft;
      ft.dwLowDateTime = (DWORD)(converted & 0xFFFFFFFF);
      ft.dwHighDateTime = (DWORD)(converted >> 32);
      if(!SetFileTime(hfile, NULL, &ft, &ft)) {
        warnf(global, "Failed to set filetime %" CURL_FORMAT_CURL_OFF_T
              " on outfile: SetFileTime failed: GetLastError %u",
              filetime, (unsigned int)GetLastError());
      }
      CloseHandle(hfile);
    }
    else {
      warnf(global, "Failed to set filetime %" CURL_FORMAT_CURL_OFF_T
            " on outfile: CreateFile failed: GetLastError %u",
            filetime, (unsigned int)GetLastError());
    }

#elif defined(HAVE_UTIMES)
    struct timeval times[2];
    times[0].tv_sec = times[1].tv_sec = (time_t)filetime;
    times[0].tv_usec = times[1].tv_usec = 0;
    if(utimes(filename, times)) {
      warnf(global, "Failed to set filetime %" CURL_FORMAT_CURL_OFF_T
            " on '%s': %s", filetime, filename, strerror(errno));
    }

#elif defined(HAVE_UTIME)
    struct utimbuf times;
    times.actime = (time_t)filetime;
    times.modtime = (time_t)filetime;
    if(utime(filename, &times)) {
      warnf(global, "Failed to set filetime %" CURL_FORMAT_CURL_OFF_T
            " on '%s': %s", filetime, filename, strerror(errno));
    }
#endif
  }
}
#endif /* defined(HAVE_UTIME) || defined(HAVE_UTIMES) ||        \
          defined(_WIN32) */