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authorMichael Kaufmann <mail@michael-kaufmann.ch>2018-02-05 21:57:39 +0100
committerMichael Kaufmann <mail@michael-kaufmann.ch>2018-02-05 22:02:10 +0100
commitd25b0503795f1fbf557632ce870298f52f2a78c1 (patch)
treef3e73d71451c73ab3d6e39b71a057de92edd91b9 /src/tool_filetime.c
parent84ad1fd3047815f9c6e78728bb351b828eac10b1 (diff)
downloadcurl-d25b0503795f1fbf557632ce870298f52f2a78c1.tar.gz
time-cond: fix reading the file modification time on Windows
On Windows, stat() may adjust the unix file time by a daylight saving time offset. Avoid this by calling GetFileTime() instead. Fixes #2164 Closes #2204
Diffstat (limited to 'src/tool_filetime.c')
-rw-r--r--src/tool_filetime.c154
1 files changed, 154 insertions, 0 deletions
diff --git a/src/tool_filetime.c b/src/tool_filetime.c
new file mode 100644
index 000000000..6071e44d2
--- /dev/null
+++ b/src/tool_filetime.c
@@ -0,0 +1,154 @@
+/***************************************************************************
+ * _ _ ____ _
+ * 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)) */