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curl/lib/parsedate.c
Daniel Stenberg ba9963b8fa I replaced the use of 'struct tm' with a private clone of that struct simply
because the struct is declared on the stack and not all members are used so
we could just as well make struct with only struct members we actually need.
2008-10-09 21:57:51 +00:00

451 lines
12 KiB
C

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2008, 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 http://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.
*
* $Id$
***************************************************************************/
/*
A brief summary of the date string formats this parser groks:
RFC 2616 3.3.1
Sun, 06 Nov 1994 08:49:37 GMT ; RFC 822, updated by RFC 1123
Sunday, 06-Nov-94 08:49:37 GMT ; RFC 850, obsoleted by RFC 1036
Sun Nov 6 08:49:37 1994 ; ANSI C's asctime() format
we support dates without week day name:
06 Nov 1994 08:49:37 GMT
06-Nov-94 08:49:37 GMT
Nov 6 08:49:37 1994
without the time zone:
06 Nov 1994 08:49:37
06-Nov-94 08:49:37
weird order:
1994 Nov 6 08:49:37 (GNU date fails)
GMT 08:49:37 06-Nov-94 Sunday
94 6 Nov 08:49:37 (GNU date fails)
time left out:
1994 Nov 6
06-Nov-94
Sun Nov 6 94
unusual separators:
1994.Nov.6
Sun/Nov/6/94/GMT
commonly used time zone names:
Sun, 06 Nov 1994 08:49:37 CET
06 Nov 1994 08:49:37 EST
time zones specified using RFC822 style:
Sun, 12 Sep 2004 15:05:58 -0700
Sat, 11 Sep 2004 21:32:11 +0200
compact numerical date strings:
20040912 15:05:58 -0700
20040911 +0200
*/
#include "setup.h"
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h> /* for strtol() */
#endif
#include <curl/curl.h>
#include "parsedate.h"
const char * const Curl_wkday[] =
{"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"};
static const char * const weekday[] =
{ "Monday", "Tuesday", "Wednesday", "Thursday",
"Friday", "Saturday", "Sunday" };
const char * const Curl_month[]=
{ "Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
struct tzinfo {
const char *name;
int offset; /* +/- in minutes */
};
/* Here's a bunch of frequently used time zone names. These were supported
by the old getdate parser. */
#define tDAYZONE -60 /* offset for daylight savings time */
static const struct tzinfo tz[]= {
{"GMT", 0}, /* Greenwich Mean */
{"UTC", 0}, /* Universal (Coordinated) */
{"WET", 0}, /* Western European */
{"BST", 0 tDAYZONE}, /* British Summer */
{"WAT", 60}, /* West Africa */
{"AST", 240}, /* Atlantic Standard */
{"ADT", 240 tDAYZONE}, /* Atlantic Daylight */
{"EST", 300}, /* Eastern Standard */
{"EDT", 300 tDAYZONE}, /* Eastern Daylight */
{"CST", 360}, /* Central Standard */
{"CDT", 360 tDAYZONE}, /* Central Daylight */
{"MST", 420}, /* Mountain Standard */
{"MDT", 420 tDAYZONE}, /* Mountain Daylight */
{"PST", 480}, /* Pacific Standard */
{"PDT", 480 tDAYZONE}, /* Pacific Daylight */
{"YST", 540}, /* Yukon Standard */
{"YDT", 540 tDAYZONE}, /* Yukon Daylight */
{"HST", 600}, /* Hawaii Standard */
{"HDT", 600 tDAYZONE}, /* Hawaii Daylight */
{"CAT", 600}, /* Central Alaska */
{"AHST", 600}, /* Alaska-Hawaii Standard */
{"NT", 660}, /* Nome */
{"IDLW", 720}, /* International Date Line West */
{"CET", -60}, /* Central European */
{"MET", -60}, /* Middle European */
{"MEWT", -60}, /* Middle European Winter */
{"MEST", -60 tDAYZONE}, /* Middle European Summer */
{"CEST", -60 tDAYZONE}, /* Central European Summer */
{"MESZ", -60 tDAYZONE}, /* Middle European Summer */
{"FWT", -60}, /* French Winter */
{"FST", -60 tDAYZONE}, /* French Summer */
{"EET", -120}, /* Eastern Europe, USSR Zone 1 */
{"WAST", -420}, /* West Australian Standard */
{"WADT", -420 tDAYZONE}, /* West Australian Daylight */
{"CCT", -480}, /* China Coast, USSR Zone 7 */
{"JST", -540}, /* Japan Standard, USSR Zone 8 */
{"EAST", -600}, /* Eastern Australian Standard */
{"EADT", -600 tDAYZONE}, /* Eastern Australian Daylight */
{"GST", -600}, /* Guam Standard, USSR Zone 9 */
{"NZT", -720}, /* New Zealand */
{"NZST", -720}, /* New Zealand Standard */
{"NZDT", -720 tDAYZONE}, /* New Zealand Daylight */
{"IDLE", -720}, /* International Date Line East */
};
/* returns:
-1 no day
0 monday - 6 sunday
*/
static int checkday(const char *check, size_t len)
{
int i;
const char * const *what;
bool found= FALSE;
if(len > 3)
what = &weekday[0];
else
what = &Curl_wkday[0];
for(i=0; i<7; i++) {
if(curl_strequal(check, what[0])) {
found=TRUE;
break;
}
what++;
}
return found?i:-1;
}
static int checkmonth(const char *check)
{
int i;
const char * const *what;
bool found= FALSE;
what = &Curl_month[0];
for(i=0; i<12; i++) {
if(curl_strequal(check, what[0])) {
found=TRUE;
break;
}
what++;
}
return found?i:-1; /* return the offset or -1, no real offset is -1 */
}
/* return the time zone offset between GMT and the input one, in number
of seconds or -1 if the timezone wasn't found/legal */
static int checktz(const char *check)
{
unsigned int i;
const struct tzinfo *what;
bool found= FALSE;
what = tz;
for(i=0; i< sizeof(tz)/sizeof(tz[0]); i++) {
if(curl_strequal(check, what->name)) {
found=TRUE;
break;
}
what++;
}
return found?what->offset*60:-1;
}
static void skip(const char **date)
{
/* skip everything that aren't letters or digits */
while(**date && !ISALNUM(**date))
(*date)++;
}
enum assume {
DATE_MDAY,
DATE_YEAR,
DATE_TIME
};
/* this is a clone of 'struct tm' but with all fields we don't need or use
cut out */
struct my_tm {
int tm_sec;
int tm_min;
int tm_hour;
int tm_mday;
int tm_mon;
int tm_year;
};
/* struct tm to time since epoch in GMT time zone.
* This is similar to the standard mktime function but for GMT only, and
* doesn't suffer from the various bugs and portability problems that
* some systems' implementations have.
*/
static time_t my_timegm(struct my_tm *tm)
{
static const int month_days_cumulative [12] =
{ 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
int month, year, leap_days;
if(tm->tm_year < 70)
/* we don't support years before 1970 as they will cause this function
to return a negative value */
return -1;
year = tm->tm_year + 1900;
month = tm->tm_mon;
if (month < 0) {
year += (11 - month) / 12;
month = 11 - (11 - month) % 12;
}
else if (month >= 12) {
year -= month / 12;
month = month % 12;
}
leap_days = year - (tm->tm_mon <= 1);
leap_days = ((leap_days / 4) - (leap_days / 100) + (leap_days / 400)
- (1969 / 4) + (1969 / 100) - (1969 / 400));
return ((((time_t) (year - 1970) * 365
+ leap_days + month_days_cumulative [month] + tm->tm_mday - 1) * 24
+ tm->tm_hour) * 60 + tm->tm_min) * 60 + tm->tm_sec;
}
static time_t parsedate(const char *date)
{
time_t t = 0;
int wdaynum=-1; /* day of the week number, 0-6 (mon-sun) */
int monnum=-1; /* month of the year number, 0-11 */
int mdaynum=-1; /* day of month, 1 - 31 */
int hournum=-1;
int minnum=-1;
int secnum=-1;
int yearnum=-1;
int tzoff=-1;
struct my_tm tm;
enum assume dignext = DATE_MDAY;
const char *indate = date; /* save the original pointer */
int part = 0; /* max 6 parts */
while(*date && (part < 6)) {
bool found=FALSE;
skip(&date);
if(ISALPHA(*date)) {
/* a name coming up */
char buf[32]="";
size_t len;
sscanf(date, "%31[ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz]",
buf);
len = strlen(buf);
if(wdaynum == -1) {
wdaynum = checkday(buf, len);
if(wdaynum != -1)
found = TRUE;
}
if(!found && (monnum == -1)) {
monnum = checkmonth(buf);
if(monnum != -1)
found = TRUE;
}
if(!found && (tzoff == -1)) {
/* this just must be a time zone string */
tzoff = checktz(buf);
if(tzoff != -1)
found = TRUE;
}
if(!found)
return -1; /* bad string */
date += len;
}
else if(ISDIGIT(*date)) {
/* a digit */
int val;
char *end;
if((secnum == -1) &&
(3 == sscanf(date, "%02d:%02d:%02d", &hournum, &minnum, &secnum))) {
/* time stamp! */
date += 8;
found = TRUE;
}
else {
val = (int)strtol(date, &end, 10);
if((tzoff == -1) &&
((end - date) == 4) &&
(val <= 1400) &&
(indate< date) &&
((date[-1] == '+' || date[-1] == '-'))) {
/* four digits and a value less than or equal to 1400 (to take into
account all sorts of funny time zone diffs) and it is preceeded
with a plus or minus. This is a time zone indication. 1400 is
picked since +1300 is frequently used and +1400 is mentioned as
an edge number in the document "ISO C 200X Proposal: Timezone
Functions" at http://david.tribble.com/text/c0xtimezone.html If
anyone has a more authoritative source for the exact maximum time
zone offsets, please speak up! */
found = TRUE;
tzoff = (val/100 * 60 + val%100)*60;
/* the + and - prefix indicates the local time compared to GMT,
this we need ther reversed math to get what we want */
tzoff = date[-1]=='+'?-tzoff:tzoff;
}
if(((end - date) == 8) &&
(yearnum == -1) &&
(monnum == -1) &&
(mdaynum == -1)) {
/* 8 digits, no year, month or day yet. This is YYYYMMDD */
found = TRUE;
yearnum = val/10000;
monnum = (val%10000)/100-1; /* month is 0 - 11 */
mdaynum = val%100;
}
if(!found && (dignext == DATE_MDAY) && (mdaynum == -1)) {
if((val > 0) && (val<32)) {
mdaynum = val;
found = TRUE;
}
dignext = DATE_YEAR;
}
if(!found && (dignext == DATE_YEAR) && (yearnum == -1)) {
yearnum = val;
found = TRUE;
if(yearnum < 1900) {
if(yearnum > 70)
yearnum += 1900;
else
yearnum += 2000;
}
if(mdaynum == -1)
dignext = DATE_MDAY;
}
if(!found)
return -1;
date = end;
}
}
part++;
}
if(-1 == secnum)
secnum = minnum = hournum = 0; /* no time, make it zero */
if((-1 == mdaynum) ||
(-1 == monnum) ||
(-1 == yearnum))
/* lacks vital info, fail */
return -1;
#if SIZEOF_TIME_T < 5
/* 32 bit time_t can only hold dates to the beginning of 2038 */
if(yearnum > 2037)
return 0x7fffffff;
#endif
tm.tm_sec = secnum;
tm.tm_min = minnum;
tm.tm_hour = hournum;
tm.tm_mday = mdaynum;
tm.tm_mon = monnum;
tm.tm_year = yearnum - 1900;
/* my_timegm() returns a time_t. time_t is often 32 bits, even on many
architectures that feature 64 bit 'long'.
Some systems have 64 bit time_t and deal with years beyond 2038. However,
even on some of the systems with 64 bit time_t mktime() returns -1 for
dates beyond 03:14:07 UTC, January 19, 2038. (Such as AIX 5100-06)
*/
t = my_timegm(&tm);
/* time zone adjust (cast t to int to compare to negative one) */
if(-1 != (int)t) {
/* Add the time zone diff between local time zone and GMT. */
long delta = (long)(tzoff!=-1?tzoff:0);
if((delta>0) && (t + delta < t))
return -1; /* time_t overflow */
t += delta;
}
return t;
}
time_t curl_getdate(const char *p, const time_t *now)
{
(void)now;
return parsedate(p);
}