1/*************************************************************************** 2 * _ _ ____ _ 3 * Project ___| | | | _ \| | 4 * / __| | | | |_) | | 5 * | (__| |_| | _ <| |___ 6 * \___|\___/|_| \_\_____| 7 * 8 * Copyright (C) 1998 - 2011, 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 http://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/* This example code only builds as-is on Windows. 23 * 24 * While Unix/Linux user, you do not need this software. 25 * You can achieve the same result as synctime using curl, awk and date. 26 * Set proxy as according to your network, but beware of proxy Cache-Control. 27 * 28 * To set your system clock, root access is required. 29 * # date -s "`curl -sI http://nist.time.gov/timezone.cgi?UTC/s/0 \ 30 * | awk -F': ' '/Date: / {print $2}'`" 31 * 32 * To view remote webserver date and time. 33 * $ curl -sI http://nist.time.gov/timezone.cgi?UTC/s/0 \ 34 * | awk -F': ' '/Date: / {print $2}' 35 * 36 * Synchronising your computer clock via Internet time server usually relies 37 * on DAYTIME, TIME, or NTP protocols. These protocols provide good accurate 38 * time synchronisation but it does not work very well through a 39 * firewall/proxy. Some adjustment has to be made to the firewall/proxy for 40 * these protocols to work properly. 41 * 42 * There is an indirect method. Since most webserver provide server time in 43 * their HTTP header, therefore you could synchronise your computer clock 44 * using HTTP protocol which has no problem with firewall/proxy. 45 * 46 * For this software to work, you should take note of these items. 47 * 1. Your firewall/proxy must allow your computer to surf internet. 48 * 2. Webserver system time must in sync with the NTP time server, 49 * or at least provide an accurate time keeping. 50 * 3. Webserver HTTP header does not provide the milliseconds units, 51 * so there is no way to get very accurate time. 52 * 4. This software could only provide an accuracy of +- a few seconds, 53 * as Round-Trip delay time is not taken into consideration. 54 * Compensation of network, firewall/proxy delay cannot be simply divide 55 * the Round-Trip delay time by half. 56 * 5. Win32 SetSystemTime() API will set your computer clock according to 57 * GMT/UTC time. Therefore your computer timezone must be properly set. 58 * 6. Webserver data should not be cached by the proxy server. Some 59 * webserver provide Cache-Control to prevent caching. 60 * 61 * References: 62 * http://tf.nist.gov/timefreq/service/its.htm 63 * http://tf.nist.gov/timefreq/service/firewall.htm 64 * 65 * Usage: 66 * This software will synchronise your computer clock only when you issue 67 * it with --synctime. By default, it only display the webserver's clock. 68 * 69 * Written by: Frank (contributed to libcurl) 70 * 71 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, 72 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY 73 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 74 * 75 * IN NO EVENT SHALL THE AUTHOR OF THIS SOFTWARE BE LIABLE FOR 76 * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, 77 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, 78 * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF 79 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 80 * OF THIS SOFTWARE. 81 * 82 */ 83 84#include <stdio.h> 85#include <time.h> 86#ifndef __CYGWIN__ 87#include <windows.h> 88#endif 89#include <curl/curl.h> 90 91 92#define MAX_STRING 256 93#define MAX_STRING1 MAX_STRING+1 94 95typedef struct 96{ 97 char http_proxy[MAX_STRING1]; 98 char proxy_user[MAX_STRING1]; 99 char timeserver[MAX_STRING1]; 100} conf_t; 101 102const char DefaultTimeServer[4][MAX_STRING1] = 103{ 104 "http://nist.time.gov/timezone.cgi?UTC/s/0", 105 "http://www.google.com/", 106 "http://www.worldtimeserver.com/current_time_in_UTC.aspx", 107 "http://www.worldtime.com/cgi-bin/wt.cgi" 108}; 109 110const char *DayStr[] = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"}; 111const char *MthStr[] = {"Jan", "Feb", "Mar", "Apr", "May", "Jun", 112 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"}; 113 114int ShowAllHeader; 115int AutoSyncTime; 116SYSTEMTIME SYSTime; 117SYSTEMTIME LOCALTime; 118 119#define HTTP_COMMAND_HEAD 0 120#define HTTP_COMMAND_GET 1 121 122 123size_t SyncTime_CURL_WriteOutput(void *ptr, size_t size, size_t nmemb, 124 void *stream) 125{ 126 fwrite(ptr, size, nmemb, stream); 127 return(nmemb*size); 128} 129 130size_t SyncTime_CURL_WriteHeader(void *ptr, size_t size, size_t nmemb, 131 void *stream) 132{ 133 int i, RetVal; 134 char TmpStr1[26], TmpStr2[26]; 135 136 if (ShowAllHeader == 1) 137 fprintf(stderr, "%s", (char *)(ptr)); 138 139 if (strncmp((char *)(ptr), "Date:", 5) == 0) { 140 if (ShowAllHeader == 0) 141 fprintf(stderr, "HTTP Server. %s", (char *)(ptr)); 142 143 if (AutoSyncTime == 1) { 144 *TmpStr1 = 0; 145 *TmpStr2 = 0; 146 if (strlen((char *)(ptr)) > 50) /* Can prevent buffer overflow to 147 TmpStr1 & 2? */ 148 AutoSyncTime = 0; 149 else { 150 RetVal = sscanf ((char *)(ptr), "Date: %s %hu %s %hu %hu:%hu:%hu", 151 TmpStr1, &SYSTime.wDay, TmpStr2, &SYSTime.wYear, 152 &SYSTime.wHour, &SYSTime.wMinute, &SYSTime.wSecond); 153 154 if (RetVal == 7) { 155 156 SYSTime.wMilliseconds = 500; /* adjust to midpoint, 0.5 sec */ 157 for (i=0; i<12; i++) { 158 if (strcmp(MthStr[i], TmpStr2) == 0) { 159 SYSTime.wMonth = i+1; 160 break; 161 } 162 } 163 AutoSyncTime = 3; /* Computer clock will be adjusted */ 164 } 165 else { 166 AutoSyncTime = 0; /* Error in sscanf() fields conversion */ 167 } 168 } 169 } 170 } 171 172 if (strncmp((char *)(ptr), "X-Cache: HIT", 12) == 0) { 173 fprintf(stderr, "ERROR: HTTP Server data is cached." 174 " Server Date is no longer valid.\n"); 175 AutoSyncTime = 0; 176 } 177 return(nmemb*size); 178} 179 180void SyncTime_CURL_Init(CURL *curl, char *proxy_port, 181 char *proxy_user_password) 182{ 183 if (strlen(proxy_port) > 0) 184 curl_easy_setopt(curl, CURLOPT_PROXY, proxy_port); 185 186 if (strlen(proxy_user_password) > 0) 187 curl_easy_setopt(curl, CURLOPT_PROXYUSERPWD, proxy_user_password); 188 189 /* Trick Webserver by claiming that you are using Microsoft WinXP SP2, IE6 */ 190 curl_easy_setopt(curl, CURLOPT_USERAGENT, 191 "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"); 192 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, *SyncTime_CURL_WriteOutput); 193 curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, *SyncTime_CURL_WriteHeader); 194} 195 196int SyncTime_CURL_Fetch(CURL *curl, char *URL_Str, char *OutFileName, 197 int HttpGetBody) 198{ 199 FILE *outfile; 200 CURLcode res; 201 202 outfile = NULL; 203 if (HttpGetBody == HTTP_COMMAND_HEAD) 204 curl_easy_setopt(curl, CURLOPT_NOBODY, 1L); 205 else { 206 outfile = fopen(OutFileName, "wb"); 207 curl_easy_setopt(curl, CURLOPT_WRITEDATA, outfile); 208 } 209 210 curl_easy_setopt(curl, CURLOPT_URL, URL_Str); 211 res = curl_easy_perform(curl); 212 if (outfile != NULL) 213 fclose(outfile); 214 return res; /* (CURLE_OK) */ 215} 216 217void showUsage(void) 218{ 219 fprintf(stderr, "SYNCTIME: Synchronising computer clock with time server" 220 " using HTTP protocol.\n"); 221 fprintf(stderr, "Usage : SYNCTIME [Option]\n"); 222 fprintf(stderr, "Options :\n"); 223 fprintf(stderr, " --server=WEBSERVER Use this time server instead" 224 " of default.\n"); 225 fprintf(stderr, " --showall Show all HTTP header.\n"); 226 fprintf(stderr, " --synctime Synchronising computer clock" 227 " with time server.\n"); 228 fprintf(stderr, " --proxy-user=USER[:PASS] Set proxy username and" 229 " password.\n"); 230 fprintf(stderr, " --proxy=HOST[:PORT] Use HTTP proxy on given" 231 " port.\n"); 232 fprintf(stderr, " --help Print this help.\n"); 233 fprintf(stderr, "\n"); 234 return; 235} 236 237int conf_init(conf_t *conf) 238{ 239 int i; 240 241 *conf->http_proxy = 0; 242 for (i=0; i<MAX_STRING1; i++) 243 conf->proxy_user[i] = 0; /* Clean up password from memory */ 244 *conf->timeserver = 0; 245 return 1; 246} 247 248int main(int argc, char *argv[]) 249{ 250 CURL *curl; 251 conf_t conf[1]; 252 int OptionIndex; 253 struct tm *lt; 254 struct tm *gmt; 255 time_t tt; 256 time_t tt_local; 257 time_t tt_gmt; 258 double tzonediffFloat; 259 int tzonediffWord; 260 char timeBuf[61]; 261 char tzoneBuf[16]; 262 int RetValue; 263 264 OptionIndex = 0; 265 ShowAllHeader = 0; /* Do not show HTTP Header */ 266 AutoSyncTime = 0; /* Do not synchronise computer clock */ 267 RetValue = 0; /* Successful Exit */ 268 conf_init(conf); 269 270 if (argc > 1) { 271 while (OptionIndex < argc) { 272 if (strncmp(argv[OptionIndex], "--server=", 9) == 0) 273 snprintf(conf->timeserver, MAX_STRING, "%s", &argv[OptionIndex][9]); 274 275 if (strcmp(argv[OptionIndex], "--showall") == 0) 276 ShowAllHeader = 1; 277 278 if (strcmp(argv[OptionIndex], "--synctime") == 0) 279 AutoSyncTime = 1; 280 281 if (strncmp(argv[OptionIndex], "--proxy-user=", 13) == 0) 282 snprintf(conf->proxy_user, MAX_STRING, "%s", &argv[OptionIndex][13]); 283 284 if (strncmp(argv[OptionIndex], "--proxy=", 8) == 0) 285 snprintf(conf->http_proxy, MAX_STRING, "%s", &argv[OptionIndex][8]); 286 287 if ((strcmp(argv[OptionIndex], "--help") == 0) || 288 (strcmp(argv[OptionIndex], "/?") == 0)) { 289 showUsage(); 290 return 0; 291 } 292 OptionIndex++; 293 } 294 } 295 296 if (*conf->timeserver == 0) /* Use default server for time information */ 297 snprintf(conf->timeserver, MAX_STRING, "%s", DefaultTimeServer[0]); 298 299 /* Init CURL before usage */ 300 curl_global_init(CURL_GLOBAL_ALL); 301 curl = curl_easy_init(); 302 if (curl) { 303 SyncTime_CURL_Init(curl, conf->http_proxy, conf->proxy_user); 304 305 /* Calculating time diff between GMT and localtime */ 306 tt = time(0); 307 lt = localtime(&tt); 308 tt_local = mktime(lt); 309 gmt = gmtime(&tt); 310 tt_gmt = mktime(gmt); 311 tzonediffFloat = difftime(tt_local, tt_gmt); 312 tzonediffWord = (int)(tzonediffFloat/3600.0); 313 314 if ((double)(tzonediffWord * 3600) == tzonediffFloat) 315 snprintf(tzoneBuf, 15, "%+03d'00'", tzonediffWord); 316 else 317 snprintf(tzoneBuf, 15, "%+03d'30'", tzonediffWord); 318 319 /* Get current system time and local time */ 320 GetSystemTime(&SYSTime); 321 GetLocalTime(&LOCALTime); 322 snprintf(timeBuf, 60, "%s, %02d %s %04d %02d:%02d:%02d.%03d, ", 323 DayStr[LOCALTime.wDayOfWeek], LOCALTime.wDay, 324 MthStr[LOCALTime.wMonth-1], LOCALTime.wYear, 325 LOCALTime.wHour, LOCALTime.wMinute, LOCALTime.wSecond, 326 LOCALTime.wMilliseconds); 327 328 fprintf(stderr, "Fetch: %s\n\n", conf->timeserver); 329 fprintf(stderr, "Before HTTP. Date: %s%s\n\n", timeBuf, tzoneBuf); 330 331 /* HTTP HEAD command to the Webserver */ 332 SyncTime_CURL_Fetch(curl, conf->timeserver, "index.htm", 333 HTTP_COMMAND_HEAD); 334 335 GetLocalTime(&LOCALTime); 336 snprintf(timeBuf, 60, "%s, %02d %s %04d %02d:%02d:%02d.%03d, ", 337 DayStr[LOCALTime.wDayOfWeek], LOCALTime.wDay, 338 MthStr[LOCALTime.wMonth-1], LOCALTime.wYear, 339 LOCALTime.wHour, LOCALTime.wMinute, LOCALTime.wSecond, 340 LOCALTime.wMilliseconds); 341 fprintf(stderr, "\nAfter HTTP. Date: %s%s\n", timeBuf, tzoneBuf); 342 343 if (AutoSyncTime == 3) { 344 /* Synchronising computer clock */ 345 if (!SetSystemTime(&SYSTime)) { /* Set system time */ 346 fprintf(stderr, "ERROR: Unable to set system time.\n"); 347 RetValue = 1; 348 } 349 else { 350 /* Successfully re-adjusted computer clock */ 351 GetLocalTime(&LOCALTime); 352 snprintf(timeBuf, 60, "%s, %02d %s %04d %02d:%02d:%02d.%03d, ", 353 DayStr[LOCALTime.wDayOfWeek], LOCALTime.wDay, 354 MthStr[LOCALTime.wMonth-1], LOCALTime.wYear, 355 LOCALTime.wHour, LOCALTime.wMinute, LOCALTime.wSecond, 356 LOCALTime.wMilliseconds); 357 fprintf(stderr, "\nNew System's Date: %s%s\n", timeBuf, tzoneBuf); 358 } 359 } 360 361 /* Cleanup before exit */ 362 conf_init(conf); 363 curl_easy_cleanup(curl); 364 } 365 return RetValue; 366} 367