mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-04 09:59:32 +00:00
![Thomas Gleixner](/assets/img/avatar_default.png)
ktime is a union because the initial implementation stored the time in scalar nanoseconds on 64 bit machine and in a endianess optimized timespec variant for 32bit machines. The Y2038 cleanup removed the timespec variant and switched everything to scalar nanoseconds. The union remained, but become completely pointless. Get rid of the union and just keep ktime_t as simple typedef of type s64. The conversion was done with coccinelle and some manual mopping up. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
291 lines
8.1 KiB
C
291 lines
8.1 KiB
C
/*
|
|
* xt_time
|
|
* Copyright © CC Computer Consultants GmbH, 2007
|
|
*
|
|
* based on ipt_time by Fabrice MARIE <fabrice@netfilter.org>
|
|
* This is a module which is used for time matching
|
|
* It is using some modified code from dietlibc (localtime() function)
|
|
* that you can find at http://www.fefe.de/dietlibc/
|
|
* This file is distributed under the terms of the GNU General Public
|
|
* License (GPL). Copies of the GPL can be obtained from gnu.org/gpl.
|
|
*/
|
|
#include <linux/ktime.h>
|
|
#include <linux/module.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/types.h>
|
|
#include <linux/netfilter/x_tables.h>
|
|
#include <linux/netfilter/xt_time.h>
|
|
|
|
struct xtm {
|
|
u_int8_t month; /* (1-12) */
|
|
u_int8_t monthday; /* (1-31) */
|
|
u_int8_t weekday; /* (1-7) */
|
|
u_int8_t hour; /* (0-23) */
|
|
u_int8_t minute; /* (0-59) */
|
|
u_int8_t second; /* (0-59) */
|
|
unsigned int dse;
|
|
};
|
|
|
|
extern struct timezone sys_tz; /* ouch */
|
|
|
|
static const u_int16_t days_since_year[] = {
|
|
0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334,
|
|
};
|
|
|
|
static const u_int16_t days_since_leapyear[] = {
|
|
0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335,
|
|
};
|
|
|
|
/*
|
|
* Since time progresses forward, it is best to organize this array in reverse,
|
|
* to minimize lookup time.
|
|
*/
|
|
enum {
|
|
DSE_FIRST = 2039,
|
|
SECONDS_PER_DAY = 86400,
|
|
};
|
|
static const u_int16_t days_since_epoch[] = {
|
|
/* 2039 - 2030 */
|
|
25202, 24837, 24472, 24106, 23741, 23376, 23011, 22645, 22280, 21915,
|
|
/* 2029 - 2020 */
|
|
21550, 21184, 20819, 20454, 20089, 19723, 19358, 18993, 18628, 18262,
|
|
/* 2019 - 2010 */
|
|
17897, 17532, 17167, 16801, 16436, 16071, 15706, 15340, 14975, 14610,
|
|
/* 2009 - 2000 */
|
|
14245, 13879, 13514, 13149, 12784, 12418, 12053, 11688, 11323, 10957,
|
|
/* 1999 - 1990 */
|
|
10592, 10227, 9862, 9496, 9131, 8766, 8401, 8035, 7670, 7305,
|
|
/* 1989 - 1980 */
|
|
6940, 6574, 6209, 5844, 5479, 5113, 4748, 4383, 4018, 3652,
|
|
/* 1979 - 1970 */
|
|
3287, 2922, 2557, 2191, 1826, 1461, 1096, 730, 365, 0,
|
|
};
|
|
|
|
static inline bool is_leap(unsigned int y)
|
|
{
|
|
return y % 4 == 0 && (y % 100 != 0 || y % 400 == 0);
|
|
}
|
|
|
|
/*
|
|
* Each network packet has a (nano)seconds-since-the-epoch (SSTE) timestamp.
|
|
* Since we match against days and daytime, the SSTE value needs to be
|
|
* computed back into human-readable dates.
|
|
*
|
|
* This is done in three separate functions so that the most expensive
|
|
* calculations are done last, in case a "simple match" can be found earlier.
|
|
*/
|
|
static inline unsigned int localtime_1(struct xtm *r, time_t time)
|
|
{
|
|
unsigned int v, w;
|
|
|
|
/* Each day has 86400s, so finding the hour/minute is actually easy. */
|
|
v = time % SECONDS_PER_DAY;
|
|
r->second = v % 60;
|
|
w = v / 60;
|
|
r->minute = w % 60;
|
|
r->hour = w / 60;
|
|
return v;
|
|
}
|
|
|
|
static inline void localtime_2(struct xtm *r, time_t time)
|
|
{
|
|
/*
|
|
* Here comes the rest (weekday, monthday). First, divide the SSTE
|
|
* by seconds-per-day to get the number of _days_ since the epoch.
|
|
*/
|
|
r->dse = time / 86400;
|
|
|
|
/*
|
|
* 1970-01-01 (w=0) was a Thursday (4).
|
|
* -1 and +1 map Sunday properly onto 7.
|
|
*/
|
|
r->weekday = (4 + r->dse - 1) % 7 + 1;
|
|
}
|
|
|
|
static void localtime_3(struct xtm *r, time_t time)
|
|
{
|
|
unsigned int year, i, w = r->dse;
|
|
|
|
/*
|
|
* In each year, a certain number of days-since-the-epoch have passed.
|
|
* Find the year that is closest to said days.
|
|
*
|
|
* Consider, for example, w=21612 (2029-03-04). Loop will abort on
|
|
* dse[i] <= w, which happens when dse[i] == 21550. This implies
|
|
* year == 2009. w will then be 62.
|
|
*/
|
|
for (i = 0, year = DSE_FIRST; days_since_epoch[i] > w;
|
|
++i, --year)
|
|
/* just loop */;
|
|
|
|
w -= days_since_epoch[i];
|
|
|
|
/*
|
|
* By now we have the current year, and the day of the year.
|
|
* r->yearday = w;
|
|
*
|
|
* On to finding the month (like above). In each month, a certain
|
|
* number of days-since-New Year have passed, and find the closest
|
|
* one.
|
|
*
|
|
* Consider w=62 (in a non-leap year). Loop will abort on
|
|
* dsy[i] < w, which happens when dsy[i] == 31+28 (i == 2).
|
|
* Concludes i == 2, i.e. 3rd month => March.
|
|
*
|
|
* (A different approach to use would be to subtract a monthlength
|
|
* from w repeatedly while counting.)
|
|
*/
|
|
if (is_leap(year)) {
|
|
/* use days_since_leapyear[] in a leap year */
|
|
for (i = ARRAY_SIZE(days_since_leapyear) - 1;
|
|
i > 0 && days_since_leapyear[i] > w; --i)
|
|
/* just loop */;
|
|
r->monthday = w - days_since_leapyear[i] + 1;
|
|
} else {
|
|
for (i = ARRAY_SIZE(days_since_year) - 1;
|
|
i > 0 && days_since_year[i] > w; --i)
|
|
/* just loop */;
|
|
r->monthday = w - days_since_year[i] + 1;
|
|
}
|
|
|
|
r->month = i + 1;
|
|
}
|
|
|
|
static bool
|
|
time_mt(const struct sk_buff *skb, struct xt_action_param *par)
|
|
{
|
|
const struct xt_time_info *info = par->matchinfo;
|
|
unsigned int packet_time;
|
|
struct xtm current_time;
|
|
s64 stamp;
|
|
|
|
/*
|
|
* We cannot use get_seconds() instead of __net_timestamp() here.
|
|
* Suppose you have two rules:
|
|
* 1. match before 13:00
|
|
* 2. match after 13:00
|
|
* If you match against processing time (get_seconds) it
|
|
* may happen that the same packet matches both rules if
|
|
* it arrived at the right moment before 13:00.
|
|
*/
|
|
if (skb->tstamp == 0)
|
|
__net_timestamp((struct sk_buff *)skb);
|
|
|
|
stamp = ktime_to_ns(skb->tstamp);
|
|
stamp = div_s64(stamp, NSEC_PER_SEC);
|
|
|
|
if (info->flags & XT_TIME_LOCAL_TZ)
|
|
/* Adjust for local timezone */
|
|
stamp -= 60 * sys_tz.tz_minuteswest;
|
|
|
|
/*
|
|
* xt_time will match when _all_ of the following hold:
|
|
* - 'now' is in the global time range date_start..date_end
|
|
* - 'now' is in the monthday mask
|
|
* - 'now' is in the weekday mask
|
|
* - 'now' is in the daytime range time_start..time_end
|
|
* (and by default, libxt_time will set these so as to match)
|
|
*/
|
|
|
|
if (stamp < info->date_start || stamp > info->date_stop)
|
|
return false;
|
|
|
|
packet_time = localtime_1(¤t_time, stamp);
|
|
|
|
if (info->daytime_start < info->daytime_stop) {
|
|
if (packet_time < info->daytime_start ||
|
|
packet_time > info->daytime_stop)
|
|
return false;
|
|
} else {
|
|
if (packet_time < info->daytime_start &&
|
|
packet_time > info->daytime_stop)
|
|
return false;
|
|
|
|
/** if user asked to ignore 'next day', then e.g.
|
|
* '1 PM Wed, August 1st' should be treated
|
|
* like 'Tue 1 PM July 31st'.
|
|
*
|
|
* This also causes
|
|
* 'Monday, "23:00 to 01:00", to match for 2 hours, starting
|
|
* Monday 23:00 to Tuesday 01:00.
|
|
*/
|
|
if ((info->flags & XT_TIME_CONTIGUOUS) &&
|
|
packet_time <= info->daytime_stop)
|
|
stamp -= SECONDS_PER_DAY;
|
|
}
|
|
|
|
localtime_2(¤t_time, stamp);
|
|
|
|
if (!(info->weekdays_match & (1 << current_time.weekday)))
|
|
return false;
|
|
|
|
/* Do not spend time computing monthday if all days match anyway */
|
|
if (info->monthdays_match != XT_TIME_ALL_MONTHDAYS) {
|
|
localtime_3(¤t_time, stamp);
|
|
if (!(info->monthdays_match & (1 << current_time.monthday)))
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static int time_mt_check(const struct xt_mtchk_param *par)
|
|
{
|
|
const struct xt_time_info *info = par->matchinfo;
|
|
|
|
if (info->daytime_start > XT_TIME_MAX_DAYTIME ||
|
|
info->daytime_stop > XT_TIME_MAX_DAYTIME) {
|
|
pr_info("invalid argument - start or "
|
|
"stop time greater than 23:59:59\n");
|
|
return -EDOM;
|
|
}
|
|
|
|
if (info->flags & ~XT_TIME_ALL_FLAGS) {
|
|
pr_info("unknown flags 0x%x\n", info->flags & ~XT_TIME_ALL_FLAGS);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if ((info->flags & XT_TIME_CONTIGUOUS) &&
|
|
info->daytime_start < info->daytime_stop)
|
|
return -EINVAL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct xt_match xt_time_mt_reg __read_mostly = {
|
|
.name = "time",
|
|
.family = NFPROTO_UNSPEC,
|
|
.match = time_mt,
|
|
.checkentry = time_mt_check,
|
|
.matchsize = sizeof(struct xt_time_info),
|
|
.me = THIS_MODULE,
|
|
};
|
|
|
|
static int __init time_mt_init(void)
|
|
{
|
|
int minutes = sys_tz.tz_minuteswest;
|
|
|
|
if (minutes < 0) /* east of Greenwich */
|
|
printk(KERN_INFO KBUILD_MODNAME
|
|
": kernel timezone is +%02d%02d\n",
|
|
-minutes / 60, -minutes % 60);
|
|
else /* west of Greenwich */
|
|
printk(KERN_INFO KBUILD_MODNAME
|
|
": kernel timezone is -%02d%02d\n",
|
|
minutes / 60, minutes % 60);
|
|
|
|
return xt_register_match(&xt_time_mt_reg);
|
|
}
|
|
|
|
static void __exit time_mt_exit(void)
|
|
{
|
|
xt_unregister_match(&xt_time_mt_reg);
|
|
}
|
|
|
|
module_init(time_mt_init);
|
|
module_exit(time_mt_exit);
|
|
MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
|
|
MODULE_DESCRIPTION("Xtables: time-based matching");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("ipt_time");
|
|
MODULE_ALIAS("ip6t_time");
|