curl/src/tool_filetime.c

/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2018, 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.haxx.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.
 *
 ***************************************************************************/
#include "tool_filetime.h"

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

curl_off_t getfiletime(const char *filename, FILE *error_stream)
{
  curl_off_t result = -1;

/* Windows stat() may attempt to adjust the unix GMT file time by a daylight
   saving time offset and since it's 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) && (SIZEOF_CURL_OFF_T >= 8)
  HANDLE hfile;

  hfile = CreateFileA(filename, FILE_READ_ATTRIBUTES,
                      (FILE_SHARE_READ | FILE_SHARE_WRITE |
                       FILE_SHARE_DELETE),
                      NULL, OPEN_EXISTING, 0, NULL);
  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)) {
        fprintf(error_stream,
                "Failed to get filetime: underflow\n");
      }
      else {
        result = (converted - CURL_OFF_T_C(116444736000000000)) / 10000000;
      }
    }
    else {
      fprintf(error_stream,
              "Failed to get filetime: "
              "GetFileTime failed: GetLastError %u\n",
              (unsigned int)GetLastError());
    }
    CloseHandle(hfile);
  }
  else if(GetLastError() != ERROR_FILE_NOT_FOUND) {
    fprintf(error_stream,
            "Failed to get filetime: "
            "CreateFile failed: GetLastError %u\n",
            (unsigned int)GetLastError());
  }
#else
  struct_stat statbuf;
  if(-1 != stat(filename, &statbuf)) {
    result = (curl_off_t)statbuf.st_mtime;
  }
  else if(errno != ENOENT) {
    fprintf(error_stream,
            "Failed to get filetime: %s\n", strerror(errno));
  }
#endif
  return result;
}

#if defined(HAVE_UTIME) || defined(HAVE_UTIMES) || \
    (defined(WIN32) && (SIZEOF_CURL_OFF_T >= 8))
void setfiletime(curl_off_t filetime, const char *filename,
    FILE *error_stream)
{
  if(filetime >= 0) {
/* Windows utime() may attempt to adjust the unix GMT file time by a daylight
   saving time offset and since it's 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) && (SIZEOF_CURL_OFF_T >= 8)
    HANDLE hfile;

    /* 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)) {
      fprintf(error_stream,
              "Failed to set filetime %" CURL_FORMAT_CURL_OFF_T
              " on outfile: overflow\n", filetime);
      return;
    }

    hfile = CreateFileA(filename, FILE_WRITE_ATTRIBUTES,
                        (FILE_SHARE_READ | FILE_SHARE_WRITE |
                         FILE_SHARE_DELETE),
                        NULL, OPEN_EXISTING, 0, NULL);
    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)) {
        fprintf(error_stream,
                "Failed to set filetime %" CURL_FORMAT_CURL_OFF_T
                " on outfile: SetFileTime failed: GetLastError %u\n",
                filetime, (unsigned int)GetLastError());
      }
      CloseHandle(hfile);
    }
    else {
      fprintf(error_stream,
              "Failed to set filetime %" CURL_FORMAT_CURL_OFF_T
              " on outfile: CreateFile failed: GetLastError %u\n",
              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)) {
      fprintf(error_stream,
              "Failed to set filetime %" CURL_FORMAT_CURL_OFF_T
              " on outfile: %s\n", filetime, strerror(errno));
    }

#elif defined(HAVE_UTIME)
    struct utimbuf times;
    times.actime = (time_t)filetime;
    times.modtime = (time_t)filetime;
    if(utime(filename, &times)) {
      fprintf(error_stream,
              "Failed to set filetime %" CURL_FORMAT_CURL_OFF_T
              " on outfile: %s\n", filetime, strerror(errno));
    }
#endif
  }
}
#endif /* defined(HAVE_UTIME) || defined(HAVE_UTIMES) || \
          (defined(WIN32) && (SIZEOF_CURL_OFF_T >= 8)) */