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wireshark/wsutil/nstime.c

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/* nstime.c
* Routines for manipulating nstime_t structures
*
* Copyright (c) 2005 MX Telecom Ltd. <richardv@mxtelecom.com>
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include <stdio.h>
#include <string.h>
#include <glib.h>
#include "nstime.h"
#include "epochs.h"
#include "time_util.h"
#ifndef HAVE_STRPTIME
# include "wsutil/strptime.h"
#endif
/* this is #defined so that we can clearly see that we have the right number of
zeros, rather than as a guard against the number of nanoseconds in a second
changing ;) */
#define NS_PER_S 1000000000
/* set the given nstime_t to zero */
void nstime_set_zero(nstime_t *nstime)
{
nstime->secs = 0;
nstime->nsecs = 0;
}
/* is the given nstime_t currently zero? */
gboolean nstime_is_zero(nstime_t *nstime)
{
if(nstime->secs == 0 && nstime->nsecs == 0) {
return TRUE;
} else {
return FALSE;
}
}
/* set the given nstime_t to (0,maxint) to mark it as "unset"
* That way we can find the first frame even when a timestamp
* is zero (fix for bug 1056)
*/
void nstime_set_unset(nstime_t *nstime)
{
nstime->secs = 0;
nstime->nsecs = G_MAXINT;
}
/* is the given nstime_t currently (0,maxint)? */
gboolean nstime_is_unset(const nstime_t *nstime)
{
if(nstime->secs == 0 && nstime->nsecs == G_MAXINT) {
return TRUE;
} else {
return FALSE;
}
}
/** function: nstime_copy
*
* a = b
*/
void nstime_copy(nstime_t *a, const nstime_t *b)
{
a->secs = b->secs;
a->nsecs = b->nsecs;
}
/*
* function: nstime_delta
* delta = b - a
*/
void nstime_delta(nstime_t *delta, const nstime_t *b, const nstime_t *a )
{
if (b->secs == a->secs) {
/* The seconds part of b is the same as the seconds part of a, so if
the nanoseconds part of the first time is less than the nanoseconds
part of a, b is before a. The nanoseconds part of the delta should
just be the difference between the nanoseconds part of b and the
nanoseconds part of a; don't adjust the seconds part of the delta,
as it's OK if the nanoseconds part is negative, and an overflow
can never result. */
delta->secs = 0;
delta->nsecs = b->nsecs - a->nsecs;
} else if (b->secs < a->secs) {
/* The seconds part of b is less than the seconds part of a, so b is
before a.
Both the "seconds" and "nanoseconds" value of the delta
should have the same sign, so if the difference between the
nanoseconds values would be *positive*, subtract 1,000,000,000
from it, and add one to the seconds value. */
delta->secs = b->secs - a->secs;
delta->nsecs = b->nsecs - a->nsecs;
if(delta->nsecs > 0) {
delta->nsecs -= NS_PER_S;
delta->secs ++;
}
} else {
delta->secs = b->secs - a->secs;
delta->nsecs = b->nsecs - a->nsecs;
if(delta->nsecs < 0) {
delta->nsecs += NS_PER_S;
delta->secs --;
}
}
}
/*
* function: nstime_sum
* sum = a + b
*/
void nstime_sum(nstime_t *sum, const nstime_t *a, const nstime_t *b)
{
sum->secs = a->secs + b->secs;
sum->nsecs = a->nsecs + b->nsecs;
if(sum->nsecs>=NS_PER_S || (sum->nsecs>0 && sum->secs<0)){
sum->nsecs-=NS_PER_S;
sum->secs++;
} else if(sum->nsecs<=-NS_PER_S || (sum->nsecs<0 && sum->secs>0)) {
sum->nsecs+=NS_PER_S;
sum->secs--;
}
}
/*
* function: nstime_cmp
*
* a > b : > 0
* a = b : 0
* a < b : < 0
*/
int nstime_cmp (const nstime_t *a, const nstime_t *b )
{
if (G_UNLIKELY(nstime_is_unset(a))) {
if (G_UNLIKELY(nstime_is_unset(b))) {
return 0; /* "no time stamp" is "equal" to "no time stamp" */
} else {
return -1; /* and is less than all time stamps */
}
} else {
if (G_UNLIKELY(nstime_is_unset(b))) {
return 1;
}
}
if (a->secs == b->secs) {
return a->nsecs - b->nsecs;
} else {
return (int) (a->secs - b->secs);
}
}
/*
* function: nstime_to_msec
* converts nstime to double, time base is milli seconds
*/
double nstime_to_msec(const nstime_t *nstime)
{
return ((double)nstime->secs*1000 + (double)nstime->nsecs/1000000);
}
/*
* function: nstime_to_sec
* converts nstime to double, time base is seconds
*/
double nstime_to_sec(const nstime_t *nstime)
{
return ((double)nstime->secs + (double)nstime->nsecs/NS_PER_S);
}
/*
* This code is based on the Samba code:
*
* Unix SMB/Netbios implementation.
* Version 1.9.
* time handling functions
* Copyright (C) Andrew Tridgell 1992-1998
*/
#ifndef TIME_T_MIN
#define TIME_T_MIN ((time_t) ((time_t)0 < (time_t) -1 ? (time_t) 0 \
: (time_t) (~0ULL << (sizeof (time_t) * CHAR_BIT - 1))))
#endif
#ifndef TIME_T_MAX
#define TIME_T_MAX ((time_t) (~ (time_t) 0 - TIME_T_MIN))
#endif
static gboolean
common_filetime_to_nstime(nstime_t *nstime, guint64 ftsecs, int nsecs)
{
gint64 secs;
/*
* Shift the seconds from the Windows epoch to the UN*X epoch.
* ftsecs's value should fit in a 64-bit signed variable, as
* ftsecs is derived from a 64-bit fractions-of-a-second value,
* and is far from the maximum 64-bit signed value, and
* EPOCH_DELTA_1601_01_01_00_00_00_UTC is also far from the
* maximum 64-bit signed value, so the difference between them
* should also fit in a 64-bit signed value.
*/
secs = (gint64)ftsecs - EPOCH_DELTA_1601_01_01_00_00_00_UTC;
if (!(TIME_T_MIN <= secs && secs <= TIME_T_MAX)) {
/* The result won't fit in a time_t */
return FALSE;
}
/*
* Get the time as seconds and nanoseconds.
*/
nstime->secs = (time_t) secs;
nstime->nsecs = nsecs;
return TRUE;
}
/*
* function: filetime_to_nstime
* converts a Windows FILETIME value to an nstime_t
* returns TRUE if the conversion succeeds, FALSE if it doesn't
* (for example, with a 32-bit time_t, the time overflows or
* underflows time_t)
*/
gboolean
filetime_to_nstime(nstime_t *nstime, guint64 filetime)
{
guint64 ftsecs;
int nsecs;
/*
* Split into seconds and tenths of microseconds, and
* then convert tenths of microseconds to nanoseconds.
*/
ftsecs = filetime / 10000000;
nsecs = (int)((filetime % 10000000)*100);
return common_filetime_to_nstime(nstime, ftsecs, nsecs);
}
/*
* function: nsfiletime_to_nstime
* converts a Windows FILETIME-like value, but given in nanoseconds
* rather than 10ths of microseconds, to an nstime_t
* returns TRUE if the conversion succeeds, FALSE if it doesn't
* (for example, with a 32-bit time_t, the time overflows or
* underflows time_t)
*/
gboolean
nsfiletime_to_nstime(nstime_t *nstime, guint64 nsfiletime)
{
guint64 ftsecs;
int nsecs;
/* Split into seconds and nanoseconds. */
ftsecs = nsfiletime / NS_PER_S;
nsecs = (int)(nsfiletime % NS_PER_S);
return common_filetime_to_nstime(nstime, ftsecs, nsecs);
}
/*
* function: iso8601_to_nstime
* parses a character string for a date and time given in
* ISO 8601 date-time format (eg: 2014-04-07T05:41:56.782+00:00)
* and converts to an nstime_t
* returns number of chars parsed on success, or 0 on failure
*
* NB. ISO 8601 is actually a lot more flexible than the above format,
* much to a developer's chagrin. The "basic format" is distinguished from
* the "extended format" by lacking the - and : separators. This function
* supports both the basic and extended format (as well as both simultaneously)
* with several common options and extensions. Time resolution is supported
* up to nanoseconds (9 fractional digits) or down to whole minutes (omitting
* the seconds component in the latter case). The T separator can be replaced
* by a space in either format (a common extension not in ISO 8601 but found
* in, e.g., RFC 3339) or omitted entirely in the basic format.
*
* Many standards that use ISO 8601 implement profiles with additional
* constraints, such as requiring that the seconds field be present, only
* allowing "." as the decimal separator, or limiting the number of fractional
* digits. Callers that wish to check constraints not yet enforced by a
* profile supported by the function must do so themselves.
*
* Future improvements could parse other ISO 8601 formats, such as
* YYYY-Www-D, YYYY-DDD, etc. For a relatively easy introduction to
* these formats, see wikipedia: https://en.wikipedia.org/wiki/ISO_8601
*/
guint8
iso8601_to_nstime(nstime_t *nstime, const char *ptr, iso8601_fmt_e format)
{
struct tm tm;
gint n_scanned = 0;
gint n_chars = 0;
guint frac = 0;
gint off_hr = 0;
gint off_min = 0;
guint8 ret_val = 0;
const char *start = ptr;
char sign = '\0';
gboolean has_separator = FALSE;
gboolean have_offset = FALSE;
memset(&tm, 0, sizeof(tm));
tm.tm_isdst = -1;
nstime_set_unset(nstime);
/* Verify that we start with a four digit year and then look for the
* separator. */
for (n_scanned = 0; n_scanned < 4; n_scanned++) {
if (!g_ascii_isdigit(*ptr)) {
return 0;
}
tm.tm_year *= 10;
tm.tm_year += *ptr++ - '0';
}
if (*ptr == '-') {
switch (format) {
case ISO8601_DATETIME_BASIC:
return 0;
case ISO8601_DATETIME:
case ISO8601_DATETIME_AUTO:
default:
has_separator = TRUE;
ptr++;
};
} else if (g_ascii_isdigit(*ptr)) {
switch (format) {
case ISO8601_DATETIME:
return 0;
case ISO8601_DATETIME_BASIC:
case ISO8601_DATETIME_AUTO:
default:
has_separator = FALSE;
};
} else {
return 0;
}
tm.tm_year -= 1900; /* struct tm expects number of years since 1900 */
/* Note: sscanf is known to be inconsistent across platforms with respect
to whether a %n is counted as a return value or not (XXX: Is this
still true, despite the express comments of C99 §7.19.6.2 12?), so we
use '<'/'>='
*/
/* XXX: sscanf allows an optional sign indicator before each integer
* converted (whether with %d or %u), so this will convert some bogus
* strings. Either checking afterwards or doing the whole thing by hand
* as with the year above is the only correct way. (strptime certainly
* can't handle the basic format.)
*/
n_scanned = sscanf(ptr, has_separator ? "%2u-%2u%n" : "%2u%2u%n",
&tm.tm_mon,
&tm.tm_mday,
&n_chars);
if (n_scanned >= 2) {
/* Got year, month, and day */
tm.tm_mon--; /* struct tm expects 0-based month */
ptr += n_chars;
}
else {
return 0;
}
if (*ptr == 'T' || *ptr == ' ') {
/* The 'T' between date and time is optional if the meaning is
unambiguous. We also allow for ' ' here per RFC 3339 to support
formats such as editcap's -A/-B options. */
ptr++;
}
else if (has_separator) {
/* Allow no separator between date and time iff we have no
separator between units. (Some extended formats may negotiate
no separator here, so this could be changed.) */
return 0;
}
/* Now we're on to the time part. We'll require a minimum of hours and
minutes. */
n_scanned = sscanf(ptr, has_separator ? "%2u:%2u%n" : "%2u%2u%n",
&tm.tm_hour,
&tm.tm_min,
&n_chars);
if (n_scanned >= 2) {
ptr += n_chars;
}
else {
/* didn't get hours and minutes */
return 0;
}
/* Test for (whole) seconds */
if ((has_separator && *ptr == ':') ||
(!has_separator && g_ascii_isdigit(*ptr))) {
/* Looks like we should have them */
if (1 > sscanf(ptr, has_separator ? ":%2u%n" : "%2u%n",
&tm.tm_sec, &n_chars)) {
/* Couldn't get them */
return 0;
}
ptr += n_chars;
/* Now let's test for fractional seconds */
if (*ptr == '.' || *ptr == ',') {
/* Get fractional seconds */
ptr++;
if (1 <= sscanf(ptr, "%u%n", &frac, &n_chars)) {
/* normalize frac to nanoseconds */
if ((frac >= 1000000000) || (frac == 0)) {
frac = 0;
} else {
switch (n_chars) { /* including leading zeros */
case 1: frac *= 100000000; break;
case 2: frac *= 10000000; break;
case 3: frac *= 1000000; break;
case 4: frac *= 100000; break;
case 5: frac *= 10000; break;
case 6: frac *= 1000; break;
case 7: frac *= 100; break;
case 8: frac *= 10; break;
default: break;
}
}
ptr += n_chars;
}
/* If we didn't get frac, it's still its default of 0 */
}
}
else {
/* No seconds. ISO 8601 allows decimal fractions of a minute here,
* but that's pretty rare in practice. Could be added later if needed.
*/
tm.tm_sec = 0;
}
/* Validate what we got so far. mktime() doesn't care about strange
values but we should at least start with something valid */
if (!tm_is_valid(&tm)) {
return 0;
}
/* Check for a time zone offset */
if (*ptr == '-' || *ptr == '+' || *ptr == 'Z') {
/* Just in case somewhere decides to observe a timezone of -00:30 or
* some such. */
sign = *ptr;
/* We have a UTC-relative offset */
if (*ptr == 'Z') {
off_hr = off_min = 0;
have_offset = TRUE;
ptr++;
}
else {
n_scanned = sscanf(ptr, has_separator ? "%3d:%2d%n" : "%3d%2d%n",
&off_hr,
&off_min,
&n_chars);
if (n_scanned >= 1) {
/* Definitely got hours */
have_offset = TRUE;
if (n_scanned >= 2) {
/* Got minutes too */
ptr += n_chars;
}
else {
/* Only got hours, just move ptr past the +hh or whatever */
off_min = 0;
ptr += 3;
}
}
else {
/* Didn't get a valid offset, treat as if there's none at all */
off_hr = off_min = 0;
have_offset = FALSE;
}
}
}
if (have_offset) {
nstime->secs = mktime_utc(&tm);
if (sign == '+') {
nstime->secs += (off_hr * 3600) + (off_min * 60);
} else if (sign == '-') {
/* -00:00 is illegal according to ISO 8601, but RFC 3339 allows
* it under a convention where -00:00 means "time in UTC is known,
* local timezone is unknown." This has the same value as an
* offset of Z or +00:00, but semantically implies that UTC is
* not the preferred time zone, which is immaterial to us.
*/
nstime->secs -= ((-off_hr) * 3600) + (off_min * 60);
}
}
else {
/* No UTC offset given; ISO 8601 says this means localtime */
nstime->secs = mktime(&tm);
}
nstime->nsecs = frac;
ret_val = (guint)(ptr-start);
return ret_val;
}
/*
* function: unix_epoch_to_nstime
* parses a character string for a date and time given in
* a floating point number containing a Unix epoch date-time
* format (e.g. 1600000000.000 for Sun Sep 13 05:26:40 AM PDT 2020)
* and converts to an nstime_t
* returns number of chars parsed on success, or 0 on failure
*
* Reference: https://en.wikipedia.org/wiki/Unix_time
*/
guint8
unix_epoch_to_nstime(nstime_t *nstime, const char *ptr)
{
struct tm tm;
char *ptr_new;
gint n_chars = 0;
guint frac = 0;
guint8 ret_val = 0;
const char *start = ptr;
memset(&tm, 0, sizeof(tm));
tm.tm_isdst = -1;
nstime_set_unset(nstime);
if (!(ptr_new=strptime(ptr, "%s", &tm))) {
return 0;
}
/* No UTC offset given; ISO 8601 says this means localtime */
nstime->secs = mktime(&tm);
/* Now let's test for fractional seconds */
if (*ptr_new == '.' || *ptr_new == ',') {
/* Get fractional seconds */
ptr_new++;
if (1 <= sscanf(ptr_new, "%u%n", &frac, &n_chars)) {
/* normalize frac to nanoseconds */
if ((frac >= 1000000000) || (frac == 0)) {
frac = 0;
} else {
switch (n_chars) { /* including leading zeros */
case 1: frac *= 100000000; break;
case 2: frac *= 10000000; break;
case 3: frac *= 1000000; break;
case 4: frac *= 100000; break;
case 5: frac *= 10000; break;
case 6: frac *= 1000; break;
case 7: frac *= 100; break;
case 8: frac *= 10; break;
default: break;
}
}
ptr_new += n_chars;
}
/* If we didn't get frac, it's still its default of 0 */
}
else {
tm.tm_sec = 0;
}
nstime->nsecs = frac;
/* return pointer shift */
ret_val = (guint)(ptr_new-start);
return ret_val;
}
/*
* Editor modelines
*
* Local Variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* ex: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/
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