1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at https://curl.haxx.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 ***************************************************************************/
22 /* <DESC>
23 * Set your system time from a remote HTTP server's Date: header.
24 * </DESC>
25 */
26 /* This example code only builds as-is on Windows.
27 *
28 * While Unix/Linux user, you do not need this software.
29 * You can achieve the same result as synctime using curl, awk and date.
30 * Set proxy as according to your network, but beware of proxy Cache-Control.
31 *
32 * To set your system clock, root access is required.
33 * # date -s "`curl -sI http://nist.time.gov/timezone.cgi?UTC/s/0 \
34 * | awk -F': ' '/Date: / {print $2}'`"
35 *
36 * To view remote webserver date and time.
37 * $ curl -sI http://nist.time.gov/timezone.cgi?UTC/s/0 \
38 * | awk -F': ' '/Date: / {print $2}'
39 *
40 * Synchronising your computer clock via Internet time server usually relies
41 * on DAYTIME, TIME, or NTP protocols. These protocols provide good accurate
42 * time synchronisation but it does not work very well through a
43 * firewall/proxy. Some adjustment has to be made to the firewall/proxy for
44 * these protocols to work properly.
45 *
46 * There is an indirect method. Since most webserver provide server time in
47 * their HTTP header, therefore you could synchronise your computer clock
48 * using HTTP protocol which has no problem with firewall/proxy.
49 *
50 * For this software to work, you should take note of these items.
51 * 1. Your firewall/proxy must allow your computer to surf internet.
52 * 2. Webserver system time must in sync with the NTP time server,
53 * or at least provide an accurate time keeping.
54 * 3. Webserver HTTP header does not provide the milliseconds units,
55 * so there is no way to get very accurate time.
56 * 4. This software could only provide an accuracy of +- a few seconds,
57 * as Round-Trip delay time is not taken into consideration.
58 * Compensation of network, firewall/proxy delay cannot be simply divide
59 * the Round-Trip delay time by half.
60 * 5. Win32 SetSystemTime() API will set your computer clock according to
61 * GMT/UTC time. Therefore your computer timezone must be properly set.
62 * 6. Webserver data should not be cached by the proxy server. Some
63 * webserver provide Cache-Control to prevent caching.
64 *
65 * References:
66 * http://tf.nist.gov/timefreq/service/its.htm
67 * http://tf.nist.gov/timefreq/service/firewall.htm
68 *
69 * Usage:
70 * This software will synchronise your computer clock only when you issue
71 * it with --synctime. By default, it only display the webserver's clock.
72 *
73 * Written by: Frank (contributed to libcurl)
74 *
75 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
76 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
77 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
78 *
79 * IN NO EVENT SHALL THE AUTHOR OF THIS SOFTWARE BE LIABLE FOR
80 * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
81 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
82 * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
83 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
84 * OF THIS SOFTWARE.
85 *
86 */
87
88 #include <stdio.h>
89 #include <time.h>
90 #ifndef __CYGWIN__
91 #include <windows.h>
92 #endif
93 #include <curl/curl.h>
94
95
96 #define MAX_STRING 256
97 #define MAX_STRING1 MAX_STRING+1
98
99 #define SYNCTIME_UA "synctime/1.0"
100
101 typedef struct
102 {
103 char http_proxy[MAX_STRING1];
104 char proxy_user[MAX_STRING1];
105 char timeserver[MAX_STRING1];
106 } conf_t;
107
108 const char DefaultTimeServer[3][MAX_STRING1] =
109 {
110 "http://pool.ntp.org/",
111 "http://nist.time.gov/",
112 "http://www.google.com/"
113 };
114
115 const char *DayStr[] = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
116 const char *MthStr[] = {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
117 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
118
119 int ShowAllHeader;
120 int AutoSyncTime;
121 SYSTEMTIME SYSTime;
122 SYSTEMTIME LOCALTime;
123
124 #define HTTP_COMMAND_HEAD 0
125 #define HTTP_COMMAND_GET 1
126
127
SyncTime_CURL_WriteOutput(void * ptr,size_t size,size_t nmemb,void * stream)128 size_t SyncTime_CURL_WriteOutput(void *ptr, size_t size, size_t nmemb,
129 void *stream)
130 {
131 fwrite(ptr, size, nmemb, stream);
132 return (nmemb*size);
133 }
134
SyncTime_CURL_WriteHeader(void * ptr,size_t size,size_t nmemb,void * stream)135 size_t SyncTime_CURL_WriteHeader(void *ptr, size_t size, size_t nmemb,
136 void *stream)
137 {
138 int i, RetVal;
139 char TmpStr1[26], TmpStr2[26];
140
141 if(ShowAllHeader == 1)
142 fprintf(stderr, "%s", (char *)(ptr));
143
144 if(strncmp((char *)(ptr), "Date:", 5) == 0) {
145 if(ShowAllHeader == 0)
146 fprintf(stderr, "HTTP Server. %s", (char *)(ptr));
147
148 if(AutoSyncTime == 1) {
149 *TmpStr1 = 0;
150 *TmpStr2 = 0;
151 if(strlen((char *)(ptr)) > 50) /* Can prevent buffer overflow to
152 TmpStr1 & 2? */
153 AutoSyncTime = 0;
154 else {
155 RetVal = sscanf ((char *)(ptr), "Date: %s %hu %s %hu %hu:%hu:%hu",
156 TmpStr1, &SYSTime.wDay, TmpStr2, &SYSTime.wYear,
157 &SYSTime.wHour, &SYSTime.wMinute, &SYSTime.wSecond);
158
159 if(RetVal == 7) {
160 SYSTime.wMilliseconds = 500; /* adjust to midpoint, 0.5 sec */
161 for(i=0; i<12; i++) {
162 if(strcmp(MthStr[i], TmpStr2) == 0) {
163 SYSTime.wMonth = i+1;
164 break;
165 }
166 }
167 AutoSyncTime = 3; /* Computer clock will be adjusted */
168 }
169 else {
170 AutoSyncTime = 0; /* Error in sscanf() fields conversion */
171 }
172 }
173 }
174 }
175
176 if(strncmp((char *)(ptr), "X-Cache: HIT", 12) == 0) {
177 fprintf(stderr, "ERROR: HTTP Server data is cached."
178 " Server Date is no longer valid.\n");
179 AutoSyncTime = 0;
180 }
181 return (nmemb*size);
182 }
183
SyncTime_CURL_Init(CURL * curl,char * proxy_port,char * proxy_user_password)184 void SyncTime_CURL_Init(CURL *curl, char *proxy_port,
185 char *proxy_user_password)
186 {
187 if(strlen(proxy_port) > 0)
188 curl_easy_setopt(curl, CURLOPT_PROXY, proxy_port);
189
190 if(strlen(proxy_user_password) > 0)
191 curl_easy_setopt(curl, CURLOPT_PROXYUSERPWD, proxy_user_password);
192
193 #ifdef SYNCTIME_UA
194 curl_easy_setopt(curl, CURLOPT_USERAGENT, SYNCTIME_UA);
195 #endif
196 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, *SyncTime_CURL_WriteOutput);
197 curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, *SyncTime_CURL_WriteHeader);
198 }
199
SyncTime_CURL_Fetch(CURL * curl,char * URL_Str,char * OutFileName,int HttpGetBody)200 int SyncTime_CURL_Fetch(CURL *curl, char *URL_Str, char *OutFileName,
201 int HttpGetBody)
202 {
203 FILE *outfile;
204 CURLcode res;
205
206 outfile = NULL;
207 if(HttpGetBody == HTTP_COMMAND_HEAD)
208 curl_easy_setopt(curl, CURLOPT_NOBODY, 1L);
209 else {
210 outfile = fopen(OutFileName, "wb");
211 curl_easy_setopt(curl, CURLOPT_WRITEDATA, outfile);
212 }
213
214 curl_easy_setopt(curl, CURLOPT_URL, URL_Str);
215 res = curl_easy_perform(curl);
216 if(outfile != NULL)
217 fclose(outfile);
218 return res; /* (CURLE_OK) */
219 }
220
showUsage(void)221 void showUsage(void)
222 {
223 fprintf(stderr, "SYNCTIME: Synchronising computer clock with time server"
224 " using HTTP protocol.\n");
225 fprintf(stderr, "Usage : SYNCTIME [Option]\n");
226 fprintf(stderr, "Options :\n");
227 fprintf(stderr, " --server=WEBSERVER Use this time server instead"
228 " of default.\n");
229 fprintf(stderr, " --showall Show all HTTP header.\n");
230 fprintf(stderr, " --synctime Synchronising computer clock"
231 " with time server.\n");
232 fprintf(stderr, " --proxy-user=USER[:PASS] Set proxy username and"
233 " password.\n");
234 fprintf(stderr, " --proxy=HOST[:PORT] Use HTTP proxy on given"
235 " port.\n");
236 fprintf(stderr, " --help Print this help.\n");
237 fprintf(stderr, "\n");
238 return;
239 }
240
conf_init(conf_t * conf)241 int conf_init(conf_t *conf)
242 {
243 int i;
244
245 *conf->http_proxy = 0;
246 for(i=0; i<MAX_STRING1; i++)
247 conf->proxy_user[i] = 0; /* Clean up password from memory */
248 *conf->timeserver = 0;
249 return 1;
250 }
251
main(int argc,char * argv[])252 int main(int argc, char *argv[])
253 {
254 CURL *curl;
255 conf_t conf[1];
256 int OptionIndex;
257 struct tm *lt;
258 struct tm *gmt;
259 time_t tt;
260 time_t tt_local;
261 time_t tt_gmt;
262 double tzonediffFloat;
263 int tzonediffWord;
264 char timeBuf[61];
265 char tzoneBuf[16];
266 int RetValue;
267
268 OptionIndex = 0;
269 ShowAllHeader = 0; /* Do not show HTTP Header */
270 AutoSyncTime = 0; /* Do not synchronise computer clock */
271 RetValue = 0; /* Successful Exit */
272 conf_init(conf);
273
274 if(argc > 1) {
275 while(OptionIndex < argc) {
276 if(strncmp(argv[OptionIndex], "--server=", 9) == 0)
277 snprintf(conf->timeserver, MAX_STRING, "%s", &argv[OptionIndex][9]);
278
279 if(strcmp(argv[OptionIndex], "--showall") == 0)
280 ShowAllHeader = 1;
281
282 if(strcmp(argv[OptionIndex], "--synctime") == 0)
283 AutoSyncTime = 1;
284
285 if(strncmp(argv[OptionIndex], "--proxy-user=", 13) == 0)
286 snprintf(conf->proxy_user, MAX_STRING, "%s", &argv[OptionIndex][13]);
287
288 if(strncmp(argv[OptionIndex], "--proxy=", 8) == 0)
289 snprintf(conf->http_proxy, MAX_STRING, "%s", &argv[OptionIndex][8]);
290
291 if((strcmp(argv[OptionIndex], "--help") == 0) ||
292 (strcmp(argv[OptionIndex], "/?") == 0)) {
293 showUsage();
294 return 0;
295 }
296 OptionIndex++;
297 }
298 }
299
300 if(*conf->timeserver == 0) /* Use default server for time information */
301 snprintf(conf->timeserver, MAX_STRING, "%s", DefaultTimeServer[0]);
302
303 /* Init CURL before usage */
304 curl_global_init(CURL_GLOBAL_ALL);
305 curl = curl_easy_init();
306 if(curl) {
307 SyncTime_CURL_Init(curl, conf->http_proxy, conf->proxy_user);
308
309 /* Calculating time diff between GMT and localtime */
310 tt = time(0);
311 lt = localtime(&tt);
312 tt_local = mktime(lt);
313 gmt = gmtime(&tt);
314 tt_gmt = mktime(gmt);
315 tzonediffFloat = difftime(tt_local, tt_gmt);
316 tzonediffWord = (int)(tzonediffFloat/3600.0);
317
318 if((double)(tzonediffWord * 3600) == tzonediffFloat)
319 snprintf(tzoneBuf, 15, "%+03d'00'", tzonediffWord);
320 else
321 snprintf(tzoneBuf, 15, "%+03d'30'", tzonediffWord);
322
323 /* Get current system time and local time */
324 GetSystemTime(&SYSTime);
325 GetLocalTime(&LOCALTime);
326 snprintf(timeBuf, 60, "%s, %02d %s %04d %02d:%02d:%02d.%03d, ",
327 DayStr[LOCALTime.wDayOfWeek], LOCALTime.wDay,
328 MthStr[LOCALTime.wMonth-1], LOCALTime.wYear,
329 LOCALTime.wHour, LOCALTime.wMinute, LOCALTime.wSecond,
330 LOCALTime.wMilliseconds);
331
332 fprintf(stderr, "Fetch: %s\n\n", conf->timeserver);
333 fprintf(stderr, "Before HTTP. Date: %s%s\n\n", timeBuf, tzoneBuf);
334
335 /* HTTP HEAD command to the Webserver */
336 SyncTime_CURL_Fetch(curl, conf->timeserver, "index.htm",
337 HTTP_COMMAND_HEAD);
338
339 GetLocalTime(&LOCALTime);
340 snprintf(timeBuf, 60, "%s, %02d %s %04d %02d:%02d:%02d.%03d, ",
341 DayStr[LOCALTime.wDayOfWeek], LOCALTime.wDay,
342 MthStr[LOCALTime.wMonth-1], LOCALTime.wYear,
343 LOCALTime.wHour, LOCALTime.wMinute, LOCALTime.wSecond,
344 LOCALTime.wMilliseconds);
345 fprintf(stderr, "\nAfter HTTP. Date: %s%s\n", timeBuf, tzoneBuf);
346
347 if(AutoSyncTime == 3) {
348 /* Synchronising computer clock */
349 if(!SetSystemTime(&SYSTime)) { /* Set system time */
350 fprintf(stderr, "ERROR: Unable to set system time.\n");
351 RetValue = 1;
352 }
353 else {
354 /* Successfully re-adjusted computer clock */
355 GetLocalTime(&LOCALTime);
356 snprintf(timeBuf, 60, "%s, %02d %s %04d %02d:%02d:%02d.%03d, ",
357 DayStr[LOCALTime.wDayOfWeek], LOCALTime.wDay,
358 MthStr[LOCALTime.wMonth-1], LOCALTime.wYear,
359 LOCALTime.wHour, LOCALTime.wMinute, LOCALTime.wSecond,
360 LOCALTime.wMilliseconds);
361 fprintf(stderr, "\nNew System's Date: %s%s\n", timeBuf, tzoneBuf);
362 }
363 }
364
365 /* Cleanup before exit */
366 conf_init(conf);
367 curl_easy_cleanup(curl);
368 }
369 return RetValue;
370 }
371