curl/lib/parsedate.c
Emanuele Torre f198d33e8d
checksrc: disallow spaces before labels
Out of 415 labels throughout the code base, 86 of those labels were
not at the start of the line. Which means labels always at the start of
the line is the favoured style overall with 329 instances.

Out of the 86 labels not at the start of the line:
* 75 were indented with the same indentation level of the following line
* 8 were indented with exactly one space
* 2 were indented with one fewer indentation level then the following
  line
* 1 was indented with the indentation level of the following line minus
  three space (probably unintentional)

Co-Authored-By: Viktor Szakats

Closes #11134
2023-05-18 20:45:04 +02:00

645 lines
18 KiB
C

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 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.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.
*
* SPDX-License-Identifier: curl
*
***************************************************************************/
/*
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 "curl_setup.h"
#include <limits.h>
#include <curl/curl.h>
#include "strcase.h"
#include "warnless.h"
#include "parsedate.h"
/*
* parsedate()
*
* Returns:
*
* PARSEDATE_OK - a fine conversion
* PARSEDATE_FAIL - failed to convert
* PARSEDATE_LATER - time overflow at the far end of time_t
* PARSEDATE_SOONER - time underflow at the low end of time_t
*/
static int parsedate(const char *date, time_t *output);
#define PARSEDATE_OK 0
#define PARSEDATE_FAIL -1
#define PARSEDATE_LATER 1
#define PARSEDATE_SOONER 2
#if !defined(CURL_DISABLE_PARSEDATE) || !defined(CURL_DISABLE_FTP) || \
!defined(CURL_DISABLE_FILE)
/* These names are also used by FTP and FILE code */
const char * const Curl_wkday[] =
{"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"};
const char * const Curl_month[]=
{ "Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
#endif
#ifndef CURL_DISABLE_PARSEDATE
static const char * const weekday[] =
{ "Monday", "Tuesday", "Wednesday", "Thursday",
"Friday", "Saturday", "Sunday" };
struct tzinfo {
char name[5];
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 */
{"UT", 0}, /* Universal Time */
{"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 */
/* Next up: Military timezone names. RFC822 allowed these, but (as noted in
RFC 1123) had their signs wrong. Here we use the correct signs to match
actual military usage.
*/
{"A", 1 * 60}, /* Alpha */
{"B", 2 * 60}, /* Bravo */
{"C", 3 * 60}, /* Charlie */
{"D", 4 * 60}, /* Delta */
{"E", 5 * 60}, /* Echo */
{"F", 6 * 60}, /* Foxtrot */
{"G", 7 * 60}, /* Golf */
{"H", 8 * 60}, /* Hotel */
{"I", 9 * 60}, /* India */
/* "J", Juliet is not used as a timezone, to indicate the observer's local
time */
{"K", 10 * 60}, /* Kilo */
{"L", 11 * 60}, /* Lima */
{"M", 12 * 60}, /* Mike */
{"N", -1 * 60}, /* November */
{"O", -2 * 60}, /* Oscar */
{"P", -3 * 60}, /* Papa */
{"Q", -4 * 60}, /* Quebec */
{"R", -5 * 60}, /* Romeo */
{"S", -6 * 60}, /* Sierra */
{"T", -7 * 60}, /* Tango */
{"U", -8 * 60}, /* Uniform */
{"V", -9 * 60}, /* Victor */
{"W", -10 * 60}, /* Whiskey */
{"X", -11 * 60}, /* X-ray */
{"Y", -12 * 60}, /* Yankee */
{"Z", 0}, /* Zulu, zero meridian, a.k.a. UTC */
};
/* returns:
-1 no day
0 monday - 6 sunday
*/
static int checkday(const char *check, size_t len)
{
int i;
const char * const *what;
if(len > 3)
what = &weekday[0];
else if(len == 3)
what = &Curl_wkday[0];
else
return -1; /* too short */
for(i = 0; i<7; i++) {
size_t ilen = strlen(what[0]);
if((ilen == len) &&
strncasecompare(check, what[0], len))
return i;
what++;
}
return -1;
}
static int checkmonth(const char *check, size_t len)
{
int i;
const char * const *what = &Curl_month[0];
if(len != 3)
return -1; /* not a month */
for(i = 0; i<12; i++) {
if(strncasecompare(check, what[0], 3))
return i;
what++;
}
return -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, size_t len)
{
unsigned int i;
const struct tzinfo *what = tz;
if(len > 4) /* longer than any valid timezone */
return -1;
for(i = 0; i< sizeof(tz)/sizeof(tz[0]); i++) {
size_t ilen = strlen(what->name);
if((ilen == len) &&
strncasecompare(check, what->name, len))
return what->offset*60;
what++;
}
return -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
};
/*
* time2epoch: time stamp to seconds since epoch in GMT time zone. Similar to
* mktime but for GMT only.
*/
static time_t time2epoch(int sec, int min, int hour,
int mday, int mon, int year)
{
static const int month_days_cumulative [12] =
{ 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
int leap_days = year - (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[mon] + mday - 1) * 24
+ hour) * 60 + min) * 60 + sec;
}
/* Returns the value of a single-digit or two-digit decimal number, return
then pointer to after the number. The 'date' pointer is known to point to a
digit. */
static int oneortwodigit(const char *date, const char **endp)
{
int num = date[0] - '0';
if(ISDIGIT(date[1])) {
*endp = &date[2];
return num*10 + (date[1] - '0');
}
*endp = &date[1];
return num;
}
/* HH:MM:SS or HH:MM and accept single-digits too */
static bool match_time(const char *date,
int *h, int *m, int *s, char **endp)
{
const char *p;
int hh, mm, ss = 0;
hh = oneortwodigit(date, &p);
if((hh < 24) && (*p == ':') && ISDIGIT(p[1])) {
mm = oneortwodigit(&p[1], &p);
if(mm < 60) {
if((*p == ':') && ISDIGIT(p[1])) {
ss = oneortwodigit(&p[1], &p);
if(ss <= 60) {
/* valid HH:MM:SS */
goto match;
}
}
else {
/* valid HH:MM */
goto match;
}
}
}
return FALSE; /* not a time string */
match:
*h = hh;
*m = mm;
*s = ss;
*endp = (char *)p;
return TRUE;
}
/*
* parsedate()
*
* Returns:
*
* PARSEDATE_OK - a fine conversion
* PARSEDATE_FAIL - failed to convert
* PARSEDATE_LATER - time overflow at the far end of time_t
* PARSEDATE_SOONER - time underflow at the low end of time_t
*/
/* Wednesday is the longest name this parser knows about */
#define NAME_LEN 12
static int parsedate(const char *date, time_t *output)
{
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;
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 */
size_t len = 0;
const char *p = date;
while(ISALPHA(*p) && (len < NAME_LEN)) {
p++;
len++;
}
if(len != NAME_LEN) {
if(wdaynum == -1) {
wdaynum = checkday(date, len);
if(wdaynum != -1)
found = TRUE;
}
if(!found && (monnum == -1)) {
monnum = checkmonth(date, len);
if(monnum != -1)
found = TRUE;
}
if(!found && (tzoff == -1)) {
/* this just must be a time zone string */
tzoff = checktz(date, len);
if(tzoff != -1)
found = TRUE;
}
}
if(!found)
return PARSEDATE_FAIL; /* bad string */
date += len;
}
else if(ISDIGIT(*date)) {
/* a digit */
int val;
char *end;
if((secnum == -1) &&
match_time(date, &hournum, &minnum, &secnum, &end)) {
/* time stamp */
date = end;
}
else {
long lval;
int error;
int old_errno;
old_errno = errno;
errno = 0;
lval = strtol(date, &end, 10);
error = errno;
if(errno != old_errno)
errno = old_errno;
if(error)
return PARSEDATE_FAIL;
#if LONG_MAX != INT_MAX
if((lval > (long)INT_MAX) || (lval < (long)INT_MIN))
return PARSEDATE_FAIL;
#endif
val = curlx_sltosi(lval);
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 preceded
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 their 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 < 100) {
if(yearnum > 70)
yearnum += 1900;
else
yearnum += 2000;
}
if(mdaynum == -1)
dignext = DATE_MDAY;
}
if(!found)
return PARSEDATE_FAIL;
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 PARSEDATE_FAIL;
#ifdef HAVE_TIME_T_UNSIGNED
if(yearnum < 1970) {
/* only positive numbers cannot return earlier */
*output = TIME_T_MIN;
return PARSEDATE_SOONER;
}
#endif
#if (SIZEOF_TIME_T < 5)
#ifdef HAVE_TIME_T_UNSIGNED
/* an unsigned 32 bit time_t can only hold dates to 2106 */
if(yearnum > 2105) {
*output = TIME_T_MAX;
return PARSEDATE_LATER;
}
#else
/* a signed 32 bit time_t can only hold dates to the beginning of 2038 */
if(yearnum > 2037) {
*output = TIME_T_MAX;
return PARSEDATE_LATER;
}
if(yearnum < 1903) {
*output = TIME_T_MIN;
return PARSEDATE_SOONER;
}
#endif
#else
/* The Gregorian calendar was introduced 1582 */
if(yearnum < 1583)
return PARSEDATE_FAIL;
#endif
if((mdaynum > 31) || (monnum > 11) ||
(hournum > 23) || (minnum > 59) || (secnum > 60))
return PARSEDATE_FAIL; /* clearly an illegal date */
/* time2epoch() returns a time_t. time_t is often 32 bits, sometimes even on
architectures that feature 64 bit 'long' but ultimately time_t is the
correct data type to use.
*/
t = time2epoch(secnum, minnum, hournum, mdaynum, monnum, yearnum);
/* Add the time zone diff between local time zone and GMT. */
if(tzoff == -1)
tzoff = 0;
if((tzoff > 0) && (t > TIME_T_MAX - tzoff)) {
*output = TIME_T_MAX;
return PARSEDATE_LATER; /* time_t overflow */
}
t += tzoff;
*output = t;
return PARSEDATE_OK;
}
#else
/* disabled */
static int parsedate(const char *date, time_t *output)
{
(void)date;
*output = 0;
return PARSEDATE_OK; /* a lie */
}
#endif
time_t curl_getdate(const char *p, const time_t *now)
{
time_t parsed = -1;
int rc = parsedate(p, &parsed);
(void)now; /* legacy argument from the past that we ignore */
if(rc == PARSEDATE_OK) {
if(parsed == -1)
/* avoid returning -1 for a working scenario */
parsed++;
return parsed;
}
/* everything else is fail */
return -1;
}
/* Curl_getdate_capped() differs from curl_getdate() in that this will return
TIME_T_MAX in case the parsed time value was too big, instead of an
error. */
time_t Curl_getdate_capped(const char *p)
{
time_t parsed = -1;
int rc = parsedate(p, &parsed);
switch(rc) {
case PARSEDATE_OK:
if(parsed == -1)
/* avoid returning -1 for a working scenario */
parsed++;
return parsed;
case PARSEDATE_LATER:
/* this returns the maximum time value */
return parsed;
default:
return -1; /* everything else is fail */
}
/* UNREACHABLE */
}
/*
* Curl_gmtime() is a gmtime() replacement for portability. Do not use the
* gmtime_r() or gmtime() functions anywhere else but here.
*
*/
CURLcode Curl_gmtime(time_t intime, struct tm *store)
{
const struct tm *tm;
#ifdef HAVE_GMTIME_R
/* thread-safe version */
tm = (struct tm *)gmtime_r(&intime, store);
#else
/* !checksrc! disable BANNEDFUNC 1 */
tm = gmtime(&intime);
if(tm)
*store = *tm; /* copy the pointed struct to the local copy */
#endif
if(!tm)
return CURLE_BAD_FUNCTION_ARGUMENT;
return CURLE_OK;
}