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/*
* Copyright © 2020 Endless OS Foundation LLC
*
* SPDX-License-Identifier: LGPL-2.0+
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <https://www.gnu.org/licenses/>.
*
* Authors:
* - Philip Withnall <pwithnall@endlessos.org>
*/
#include "config.h"
#include <errno.h>
#include <glib.h>
#include <string.h>
#include "ostree-date-utils-private.h"
/* @buf must already be known to be long enough */
static gboolean
parse_uint (const char *buf,
guint n_digits,
guint min,
guint max,
guint *out)
{
guint64 number;
const char *end_ptr = NULL;
gint saved_errno = 0;
g_assert (out != NULL);
if(!(n_digits == 2 || n_digits == 4))
return FALSE;
errno = 0;
number = g_ascii_strtoull (buf, (gchar **)&end_ptr, 10);
saved_errno = errno;
if (!g_ascii_isdigit (buf[0]) ||
saved_errno != 0 ||
end_ptr == NULL ||
end_ptr != buf + n_digits ||
number < min ||
number > max)
return FALSE;
*out = number;
return TRUE;
}
/* Locale-independent parsing for RFC 2616 date/times.
*
* Reference: https://tools.ietf.org/html/rfc2616#section-3.3.1
*
* Syntax:
* <day-name>, <day> <month> <year> <hour>:<minute>:<second> GMT
*
* Note that this only accepts the full-year and GMT formats specified by
* RFC 1123. It doesn’t accept RFC 850 or asctime formats.
*
* Example:
* Wed, 21 Oct 2015 07:28:00 GMT
*/
GDateTime *
_ostree_parse_rfc2616_date_time (const char *buf,
size_t len)
{
guint day_int, year_int, hour_int, minute_int, second_int;
const char *day_names[] =
{
"Mon",
"Tue",
"Wed",
"Thu",
"Fri",
"Sat",
"Sun",
};
size_t day_name_index;
const char *month_names[] =
{
"Jan",
"Feb",
"Mar",
"Apr",
"May",
"Jun",
"Jul",
"Aug",
"Sep",
"Oct",
"Nov",
"Dec",
};
size_t month_name_index;
if (len != 29)
return NULL;
const char *day_name = buf;
const char *day = buf + 5;
const char *month_name = day + 3;
const char *year = month_name + 4;
const char *hour = year + 5;
const char *minute = hour + 3;
const char *second = minute + 3;
const char *tz = second + 3;
for (day_name_index = 0; day_name_index < G_N_ELEMENTS (day_names); day_name_index++)
{
if (strncmp (day_names[day_name_index], day_name, 3) == 0)
break;
}
if (day_name_index >= G_N_ELEMENTS (day_names))
return NULL;
/* don’t validate whether the day_name matches the rest of the date */
if (*(day_name + 3) != ',' || *(day_name + 4) != ' ')
return NULL;
if (!parse_uint (day, 2, 1, 31, &day_int))
return NULL;
if (*(day + 2) != ' ')
return NULL;
for (month_name_index = 0; month_name_index < G_N_ELEMENTS (month_names); month_name_index++)
{
if (strncmp (month_names[month_name_index], month_name, 3) == 0)
break;
}
if (month_name_index >= G_N_ELEMENTS (month_names))
return NULL;
if (*(month_name + 3) != ' ')
return NULL;
if (!parse_uint (year, 4, 0, 9999, &year_int))
return NULL;
if (*(year + 4) != ' ')
return NULL;
if (!parse_uint (hour, 2, 0, 23, &hour_int))
return NULL;
if (*(hour + 2) != ':')
return NULL;
if (!parse_uint (minute, 2, 0, 59, &minute_int))
return NULL;
if (*(minute + 2) != ':')
return NULL;
if (!parse_uint (second, 2, 0, 60, &second_int)) /* allow leap seconds */
return NULL;
if (*(second + 2) != ' ')
return NULL;
if (strncmp (tz, "GMT", 3) != 0)
return NULL;
return g_date_time_new_utc (year_int, month_name_index + 1, day_int,
hour_int, minute_int, second_int);
}
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