lib/rfc1123.c

   1
   2 /*
   3  * $Id: rfc1123.c,v 1.17 1998/04/24 05:20:23 wessels Exp $
   4  *
   5  * DEBUG:
   6  * AUTHOR: Harvest Derived
   7  *
   8  * SQUID Internet Object Cache  http://squid.nlanr.net/Squid/
   9  * --------------------------------------------------------
  10  *
  11  *  Squid is the result of efforts by numerous individuals from the
  12  *  Internet community.  Development is led by Duane Wessels of the
  13  *  National Laboratory for Applied Network Research and funded by
  14  *  the National Science Foundation.
  15  *
  16  *  This program is free software; you can redistribute it and/or modify
  17  *  it under the terms of the GNU General Public License as published by
  18  *  the Free Software Foundation; either version 2 of the License, or
  19  *  (at your option) any later version.
  20  *
  21  *  This program is distributed in the hope that it will be useful,
  22  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  *  GNU General Public License for more details.
  25  *
  26  *  You should have received a copy of the GNU General Public License
  27  *  along with this program; if not, write to the Free Software
  28  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  29  *
  30  */
  31
  32 /*
  33  * Copyright (c) 1994, 1995.  All rights reserved.
  34  *
  35  *   The Harvest software was developed by the Internet Research Task
  36  *   Force Research Group on Resource Discovery (IRTF-RD):
  37  *
  38  *         Mic Bowman of Transarc Corporation.
  39  *         Peter Danzig of the University of Southern California.
  40  *         Darren R. Hardy of the University of Colorado at Boulder.
  41  *         Udi Manber of the University of Arizona.
  42  *         Michael F. Schwartz of the University of Colorado at Boulder.
  43  *         Duane Wessels of the University of Colorado at Boulder.
  44  *
  45  *   This copyright notice applies to software in the Harvest
  46  *   ``src/'' directory only.  Users should consult the individual
  47  *   copyright notices in the ``components/'' subdirectories for
  48  *   copyright information about other software bundled with the
  49  *   Harvest source code distribution.
  50  *
  51  * TERMS OF USE
  52  *
  53  *   The Harvest software may be used and re-distributed without
  54  *   charge, provided that the software origin and research team are
  55  *   cited in any use of the system.  Most commonly this is
  56  *   accomplished by including a link to the Harvest Home Page
  57  *   (http://harvest.cs.colorado.edu/) from the query page of any
  58  *   Broker you deploy, as well as in the query result pages.  These
  59  *   links are generated automatically by the standard Broker
  60  *   software distribution.
  61  *
  62  *   The Harvest software is provided ``as is'', without express or
  63  *   implied warranty, and with no support nor obligation to assist
  64  *   in its use, correction, modification or enhancement.  We assume
  65  *   no liability with respect to the infringement of copyrights,
  66  *   trade secrets, or any patents, and are not responsible for
  67  *   consequential damages.  Proper use of the Harvest software is
  68  *   entirely the responsibility of the user.
  69  *
  70  * DERIVATIVE WORKS
  71  *
  72  *   Users may make derivative works from the Harvest software, subject
  73  *   to the following constraints:
  74  *
  75  *     - You must include the above copyright notice and these
  76  *       accompanying paragraphs in all forms of derivative works,
  77  *       and any documentation and other materials related to such
  78  *       distribution and use acknowledge that the software was
  79  *       developed at the above institutions.
  80  *
  81  *     - You must notify IRTF-RD regarding your distribution of
  82  *       the derivative work.
  83  *
  84  *     - You must clearly notify users that your are distributing
  85  *       a modified version and not the original Harvest software.
  86  *
  87  *     - Any derivative product is also subject to these copyright
  88  *       and use restrictions.
  89  *
  90  *   Note that the Harvest software is NOT in the public domain.  We
  91  *   retain copyright, as specified above.
  92  *
  93  * HISTORY OF FREE SOFTWARE STATUS
  94  *
  95  *   Originally we required sites to license the software in cases
  96  *   where they were going to build commercial products/services
  97  *   around Harvest.  In June 1995 we changed this policy.  We now
  98  *   allow people to use the core Harvest software (the code found in
  99  *   the Harvest ``src/'' directory) for free.  We made this change
 100  *   in the interest of encouraging the widest possible deployment of
 101  *   the technology.  The Harvest software is really a reference
 102  *   implementation of a set of protocols and formats, some of which
 103  *   we intend to standardize.  We encourage commercial
 104  *   re-implementations of code complying to this set of standards.
 105  */
 106
 107 #include "config.h"
 108
 109
 110 /*
 111  *  Adapted from HTSUtils.c in CERN httpd 3.0 (http://info.cern.ch/httpd/)
 112  *  by Darren Hardy <hardy@cs.colorado.edu>, November 1994.
 113  */
 114 #if HAVE_STDIO_H
 115 #include <stdio.h>
 116 #endif
 117 #if HAVE_STRING_H
 118 #include <string.h>
 119 #endif
 120 #if HAVE_CTYPE_H
 121 #include <ctype.h>
 122 #endif
 123 #if HAVE_SYS_TYPES_H
 124 #include <sys/types.h>
 125 #endif
 126 #if HAVE_TIME_H
 127 #include <time.h>
 128 #endif
 129 #if HAVE_SYS_TIME_H
 130 #include <sys/time.h>
 131 #endif
 132
 133 #include "util.h"
 134 #include "snprintf.h"
 135
 136 #define RFC850_STRFTIME "%A, %d-%b-%y %H:%M:%S GMT"
 137 #define RFC1123_STRFTIME "%a, %d %b %Y %H:%M:%S GMT"
 138
 139 static int make_month(const char *s);
 140 static int make_num(const char *s);
 141
 142 static char *month_names[12] =
 143 {
 144     "Jan", "Feb", "Mar", "Apr", "May", "Jun",
 145     "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
 146 };
 147
 148
 149 static int
 150 make_num(const char *s)
 151 {
 152     if (*s >= '0' && *s <= '9')
 153         return 10 * (*s - '0') + *(s + 1) - '0';
 154     else
 155         return *(s + 1) - '0';
 156 }
 157
 158 static int
 159 make_month(const char *s)
 160 {
 161     int i;
 162     char month[3];
 163
 164     month[0] = toupper(*s);
 165     month[1] = tolower(*(s + 1));
 166     month[2] = tolower(*(s + 2));
 167
 168     for (i = 0; i < 12; i++)
 169         if (!strncmp(month_names[i], month, 3))
 170             return i;
 171     return 0;
 172 }
 173
 174
 175 time_t
 176 parse_rfc1123(const char *str)
 177 {
 178     const char *s;
 179     struct tm tm;
 180     time_t t;
 181
 182     if (!str)
 183         return -1;
 184
 185     memset(&tm, '\0', sizeof(struct tm));
 186     if ((s = strchr(str, ','))) {       /* Thursday, 10-Jun-93 01:29:59 GMT */
 187         s++;                    /* or: Thu, 10 Jan 1993 01:29:59 GMT */
 188         while (*s == ' ')
 189             s++;
 190         if (isdigit(*s) && !isdigit(*(s+1))) /* backoff if only one digit */
 191             s--;
 192         if (strchr(s, '-')) {   /* First format */
 193             if ((int) strlen(s) < 18)
 194                 return -1;
 195             tm.tm_mday = make_num(s);
 196             tm.tm_mon = make_month(s + 3);
 197             tm.tm_year = make_num(s + 7);
 198             /*
 199              * Y2K: Arjan de Vet <Arjan.deVet@adv.IAEhv.nl>
 200              * if tm.tm_year < 70, assume it's after the year 2000.
 201              */
 202             if (tm.tm_year < 70)
 203                 tm.tm_year += 100;
 204             tm.tm_hour = make_num(s + 10);
 205             tm.tm_min = make_num(s + 13);
 206             tm.tm_sec = make_num(s + 16);
 207         } else {                /* Second format */
 208             if ((int) strlen(s) < 20)
 209                 return -1;
 210             tm.tm_mday = make_num(s);
 211             tm.tm_mon = make_month(s + 3);
 212             tm.tm_year = (100 * make_num(s + 7) - 1900) + make_num(s + 9);
 213             tm.tm_hour = make_num(s + 12);
 214             tm.tm_min = make_num(s + 15);
 215             tm.tm_sec = make_num(s + 18);
 216
 217         }
 218     } else {                    /* Try the other format:        */
 219         s = str;                /* Wed Jun  9 01:29:59 1993 GMT */
 220         while (*s && *s == ' ')
 221             s++;
 222         if ((int) strlen(s) < 24)
 223             return -1;
 224         tm.tm_mday = make_num(s + 8);
 225         tm.tm_mon = make_month(s + 4);
 226         tm.tm_year = make_num(s + 22);
 227         tm.tm_hour = make_num(s + 11);
 228         tm.tm_min = make_num(s + 14);
 229         tm.tm_sec = make_num(s + 17);
 230     }
 231     if (tm.tm_sec < 0 || tm.tm_sec > 59 ||
 232         tm.tm_min < 0 || tm.tm_min > 59 ||
 233         tm.tm_hour < 0 || tm.tm_hour > 23 ||
 234         tm.tm_mday < 1 || tm.tm_mday > 31 ||
 235         tm.tm_mon < 0 || tm.tm_mon > 11 ||
 236         tm.tm_year < 70 || tm.tm_year > 120) {
 237         return -1;
 238     }
 239     tm.tm_isdst = -1;
 240
 241 #ifdef HAVE_TIMEGM
 242     t = timegm(&tm);
 243 #elif HAVE_TM_GMTOFF
 244     t = mktime(&tm);
 245     {
 246         struct tm *local = localtime(&t);
 247         t += local->tm_gmtoff;
 248     }
 249 #else
 250     /* some systems do not have tm_gmtoff so we fake it */
 251     t = mktime(&tm);
 252     {
 253         time_t dst = 0;
 254 #if !defined _TIMEZONE && !defined _timezone
 255         extern time_t timezone;
 256 #endif
 257         /*
 258          * The following assumes a fixed DST offset of 1 hour,
 259          * which is probably wrong.
 260          */
 261         if (tm.tm_isdst > 0)
 262             dst = -3600;
 263 #ifdef _timezone
 264         t -= (_timezone + dst);
 265 #else
 266         t -= (timezone + dst);
 267 #endif
 268     }
 269 #endif
 270     return t;
 271 }
 272
 273 const char *
 274 mkrfc1123(time_t t)
 275 {
 276     static char buf[128];
 277
 278     struct tm *gmt = gmtime(&t);
 279
 280     buf[0] = '\0';
 281     strftime(buf, 127, RFC1123_STRFTIME, gmt);
 282     return buf;
 283 }
 284
 285 const char *
 286 mkhttpdlogtime(const time_t * t)
 287 {
 288     static char buf[128];
 289
 290     struct tm *gmt = gmtime(t);
 291
 292 #ifndef USE_GMT
 293     int gmt_min, gmt_hour, gmt_yday, day_offset;
 294     size_t len;
 295     struct tm *lt;
 296     int min_offset;
 297
 298     /* localtime & gmtime may use the same static data */
 299     gmt_min = gmt->tm_min;
 300     gmt_hour = gmt->tm_hour;
 301     gmt_yday = gmt->tm_yday;
 302
 303     lt = localtime(t);
 304     day_offset = lt->tm_yday - gmt_yday;
 305     min_offset = day_offset * 1440 + (lt->tm_hour - gmt_hour) * 60
 306         + (lt->tm_min - gmt_min);
 307
 308     /* wrap round on end of year */
 309     if (day_offset > 1)
 310         day_offset = -1;
 311     else if (day_offset < -1)
 312         day_offset = 1;
 313
 314     len = strftime(buf, 127 - 5, "%d/%b/%Y:%H:%M:%S ", lt);
 315     snprintf(buf + len, 128 - len, "%+03d%02d",
 316         (min_offset / 60) % 24,
 317         min_offset % 60);
 318 #else /* USE_GMT */
 319     buf[0] = '\0';
 320     strftime(buf, 127, "%d/%b/%Y:%H:%M:%S -000", gmt);
 321 #endif /* USE_GMT */
 322
 323     return buf;
 324 }
 325
 326 #if 0
 327 int
 328 main()
 329 {
 330     char *x;
 331     time_t t, pt;
 332
 333     t = time(NULL);
 334     x = mkrfc1123(t);
 335     printf("HTTP Time: %s\n", x);
 336
 337     pt = parse_rfc1123(x);
 338     printf("Parsed: %d vs. %d\n", pt, t);
 339 }
 340
 341 #endif