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ea3894c1ba26bdfe3f0299dfbe2b767ba92f91dc
systemd/src/basic/calendarspec.c
T
Lennart Poettering ea3894c1ba util-lib: add (void) cast to indicate that we don't care about the normalization success 
After all, we verify that every calendar part is not out of bounds later on,
and it's fully OK if the normalization has no effect.
2016-02-21 23:25:38 +01:00

1088 lines
28 KiB
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/***
This file is part of systemd.
Copyright 2012 Lennart Poettering
systemd 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 2.1 of the License, or
(at your option) any later version.
systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <alloca.h>
#include <errno.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include "alloc-util.h"
#include "calendarspec.h"
#include "fileio.h"
#include "macro.h"
#include "parse-util.h"
#include "string-util.h"
#define BITS_WEEKDAYS 127
static void free_chain(CalendarComponent *c) {
CalendarComponent *n;
while (c) {
n = c->next;
free(c);
c = n;
}
}
void calendar_spec_free(CalendarSpec *c) {
if (!c)
return;
free_chain(c->year);
free_chain(c->month);
free_chain(c->day);
free_chain(c->hour);
free_chain(c->minute);
free_chain(c->microsecond);
free(c);
}
static int component_compare(const void *_a, const void *_b) {
CalendarComponent * const *a = _a, * const *b = _b;
if ((*a)->value < (*b)->value)
return -1;
if ((*a)->value > (*b)->value)
return 1;
if ((*a)->repeat < (*b)->repeat)
return -1;
if ((*a)->repeat > (*b)->repeat)
return 1;
return 0;
}
static void sort_chain(CalendarComponent **c) {
unsigned n = 0, k;
CalendarComponent **b, *i, **j, *next;
assert(c);
for (i = *c; i; i = i->next)
n++;
if (n <= 1)
return;
j = b = alloca(sizeof(CalendarComponent*) * n);
for (i = *c; i; i = i->next)
*(j++) = i;
qsort(b, n, sizeof(CalendarComponent*), component_compare);
b[n-1]->next = NULL;
next = b[n-1];
/* Drop non-unique entries */
for (k = n-1; k > 0; k--) {
if (b[k-1]->value == next->value &&
b[k-1]->repeat == next->repeat) {
free(b[k-1]);
continue;
}
b[k-1]->next = next;
next = b[k-1];
}
*c = next;
}
static void fix_year(CalendarComponent *c) {
/* Turns 12 → 2012, 89 → 1989 */
while(c) {
CalendarComponent *n = c->next;
if (c->value >= 0 && c->value < 70)
c->value += 2000;
if (c->value >= 70 && c->value < 100)
c->value += 1900;
c = n;
}
}
int calendar_spec_normalize(CalendarSpec *c) {
assert(c);
if (c->weekdays_bits <= 0 || c->weekdays_bits >= BITS_WEEKDAYS)
c->weekdays_bits = -1;
fix_year(c->year);
sort_chain(&c->year);
sort_chain(&c->month);
sort_chain(&c->day);
sort_chain(&c->hour);
sort_chain(&c->minute);
sort_chain(&c->microsecond);
return 0;
}
_pure_ static bool chain_valid(CalendarComponent *c, int from, int to) {
if (!c)
return true;
if (c->value < from || c->value > to)
return false;
if (c->value + c->repeat > to)
return false;
if (c->next)
return chain_valid(c->next, from, to);
return true;
}
_pure_ bool calendar_spec_valid(CalendarSpec *c) {
assert(c);
if (c->weekdays_bits > BITS_WEEKDAYS)
return false;
if (!chain_valid(c->year, 1970, 2199))
return false;
if (!chain_valid(c->month, 1, 12))
return false;
if (!chain_valid(c->day, 1, 31))
return false;
if (!chain_valid(c->hour, 0, 23))
return false;
if (!chain_valid(c->minute, 0, 59))
return false;
if (!chain_valid(c->microsecond, 0, 60*USEC_PER_SEC-1))
return false;
return true;
}
static void format_weekdays(FILE *f, const CalendarSpec *c) {
static const char *const days[] = {
"Mon",
"Tue",
"Wed",
"Thu",
"Fri",
"Sat",
"Sun"
};
int l, x;
bool need_colon = false;
assert(f);
assert(c);
assert(c->weekdays_bits > 0 && c->weekdays_bits <= BITS_WEEKDAYS);
for (x = 0, l = -1; x < (int) ELEMENTSOF(days); x++) {
if (c->weekdays_bits & (1 << x)) {
if (l < 0) {
if (need_colon)
fputc(',', f);
else
need_colon = true;
fputs(days[x], f);
l = x;
}
} else if (l >= 0) {
if (x > l + 1) {
fputc(x > l + 2 ? '-' : ',', f);
fputs(days[x-1], f);
}
l = -1;
}
}
if (l >= 0 && x > l + 1) {
fputc(x > l + 2 ? '-' : ',', f);
fputs(days[x-1], f);
}
}
static void format_chain(FILE *f, int space, const CalendarComponent *c, bool usec) {
assert(f);
if (!c) {
fputc('*', f);
return;
}
assert(c->value >= 0);
if (!usec)
fprintf(f, "%0*i", space, c->value);
else if (c->value % USEC_PER_SEC == 0)
fprintf(f, "%0*i", space, (int) (c->value / USEC_PER_SEC));
else
fprintf(f, "%0*i.%06i", space, (int) (c->value / USEC_PER_SEC), (int) (c->value % USEC_PER_SEC));
if (c->repeat > 0) {
if (!usec)
fprintf(f, "/%i", c->repeat);
else if (c->repeat % USEC_PER_SEC == 0)
fprintf(f, "/%i", (int) (c->repeat / USEC_PER_SEC));
else
fprintf(f, "/%i.%06i", (int) (c->repeat / USEC_PER_SEC), (int) (c->repeat % USEC_PER_SEC));
}
if (c->next) {
fputc(',', f);
format_chain(f, space, c->next, usec);
}
}
int calendar_spec_to_string(const CalendarSpec *c, char **p) {
char *buf = NULL;
size_t sz = 0;
FILE *f;
int r;
assert(c);
assert(p);
f = open_memstream(&buf, &sz);
if (!f)
return -ENOMEM;
if (c->weekdays_bits > 0 && c->weekdays_bits <= BITS_WEEKDAYS) {
format_weekdays(f, c);
fputc(' ', f);
}
format_chain(f, 4, c->year, false);
fputc('-', f);
format_chain(f, 2, c->month, false);
fputc('-', f);
format_chain(f, 2, c->day, false);
fputc(' ', f);
format_chain(f, 2, c->hour, false);
fputc(':', f);
format_chain(f, 2, c->minute, false);
fputc(':', f);
format_chain(f, 2, c->microsecond, true);
if (c->utc)
fputs(" UTC", f);
r = fflush_and_check(f);
if (r < 0) {
free(buf);
fclose(f);
return r;
}
fclose(f);
*p = buf;
return 0;
}
static int parse_weekdays(const char **p, CalendarSpec *c) {
static const struct {
const char *name;
const int nr;
} day_nr[] = {
{ "Monday", 0 },
{ "Mon", 0 },
{ "Tuesday", 1 },
{ "Tue", 1 },
{ "Wednesday", 2 },
{ "Wed", 2 },
{ "Thursday", 3 },
{ "Thu", 3 },
{ "Friday", 4 },
{ "Fri", 4 },
{ "Saturday", 5 },
{ "Sat", 5 },
{ "Sunday", 6 },
{ "Sun", 6 }
};
int l = -1;
bool first = true;
assert(p);
assert(*p);
assert(c);
for (;;) {
unsigned i;
if (!first && **p == ' ')
return 0;
for (i = 0; i < ELEMENTSOF(day_nr); i++) {
size_t skip;
if (!startswith_no_case(*p, day_nr[i].name))
continue;
skip = strlen(day_nr[i].name);
if ((*p)[skip] != '-' &&
(*p)[skip] != ',' &&
(*p)[skip] != ' ' &&
(*p)[skip] != 0)
return -EINVAL;
c->weekdays_bits |= 1 << day_nr[i].nr;
if (l >= 0) {
int j;
if (l > day_nr[i].nr)
return -EINVAL;
for (j = l + 1; j < day_nr[i].nr; j++)
c->weekdays_bits |= 1 << j;
}
*p += skip;
break;
}
/* Couldn't find this prefix, so let's assume the
weekday was not specified and let's continue with
the date */
if (i >= ELEMENTSOF(day_nr))
return first ? 0 : -EINVAL;
/* We reached the end of the string */
if (**p == 0)
return 0;
/* We reached the end of the weekday spec part */
if (**p == ' ') {
*p += strspn(*p, " ");
return 0;
}
if (**p == '-') {
if (l >= 0)
return -EINVAL;
l = day_nr[i].nr;
} else
l = -1;
*p += 1;
first = false;
}
}
static int parse_component_decimal(const char **p, bool usec, unsigned long *res) {
unsigned long value;
const char *e = NULL;
char *ee = NULL;
int r;
errno = 0;
value = strtoul(*p, &ee, 10);
if (errno > 0)
return -errno;
if (ee == *p)
return -EINVAL;
if ((unsigned long) (int) value != value)
return -ERANGE;
e = ee;
if (usec) {
if (value * USEC_PER_SEC / USEC_PER_SEC != value)
return -ERANGE;
value *= USEC_PER_SEC;
if (*e == '.') {
unsigned add;
e++;
r = parse_fractional_part_u(&e, 6, &add);
if (r < 0)
return r;
if (add + value < value)
return -ERANGE;
value += add;
}
}
*p = e;
*res = value;
return 0;
}
static int prepend_component(const char **p, bool usec, CalendarComponent **c) {
unsigned long value, repeat = 0;
CalendarComponent *cc;
int r;
const char *e;
assert(p);
assert(c);
e = *p;
r = parse_component_decimal(&e, usec, &value);
if (r < 0)
return r;
if (*e == '/') {
e++;
r = parse_component_decimal(&e, usec, &repeat);
if (r < 0)
return r;
if (repeat == 0)
return -ERANGE;
}
if (*e != 0 && *e != ' ' && *e != ',' && *e != '-' && *e != ':')
return -EINVAL;
cc = new0(CalendarComponent, 1);
if (!cc)
return -ENOMEM;
cc->value = value;
cc->repeat = repeat;
cc->next = *c;
*p = e;
*c = cc;
if (*e ==',') {
*p += 1;
return prepend_component(p, usec, c);
}
return 0;
}
static int const_chain(int value, CalendarComponent **c) {
CalendarComponent *cc = NULL;
assert(c);
cc = new0(CalendarComponent, 1);
if (!cc)
return -ENOMEM;
cc->value = value;
cc->repeat = 0;
cc->next = *c;
*c = cc;
return 0;
}
static int parse_chain(const char **p, bool usec, CalendarComponent **c) {
const char *t;
CalendarComponent *cc = NULL;
int r;
assert(p);
assert(c);
t = *p;
if (t[0] == '*') {
if (usec) {
r = const_chain(0, c);
if (r < 0)
return r;
(*c)->repeat = USEC_PER_SEC;
} else
*c = NULL;
*p = t + 1;
return 0;
}
r = prepend_component(&t, usec, &cc);
if (r < 0) {
free_chain(cc);
return r;
}
*p = t;
*c = cc;
return 0;
}
static int parse_date(const char **p, CalendarSpec *c) {
const char *t;
int r;
CalendarComponent *first, *second, *third;
assert(p);
assert(*p);
assert(c);
t = *p;
if (*t == 0)
return 0;
r = parse_chain(&t, false, &first);
if (r < 0)
return r;
/* Already the end? A ':' as separator? In that case this was a time, not a date */
if (*t == 0 || *t == ':') {
free_chain(first);
return 0;
}
if (*t != '-') {
free_chain(first);
return -EINVAL;
}
t++;
r = parse_chain(&t, false, &second);
if (r < 0) {
free_chain(first);
return r;
}
/* Got two parts, hence it's month and day */
if (*t == ' ' || *t == 0) {
*p = t + strspn(t, " ");
c->month = first;
c->day = second;
return 0;
}
if (*t != '-') {
free_chain(first);
free_chain(second);
return -EINVAL;
}
t++;
r = parse_chain(&t, false, &third);
if (r < 0) {
free_chain(first);
free_chain(second);
return r;
}
/* Got tree parts, hence it is year, month and day */
if (*t == ' ' || *t == 0) {
*p = t + strspn(t, " ");
c->year = first;
c->month = second;
c->day = third;
return 0;
}
free_chain(first);
free_chain(second);
free_chain(third);
return -EINVAL;
}
static int parse_calendar_time(const char **p, CalendarSpec *c) {
CalendarComponent *h = NULL, *m = NULL, *s = NULL;
const char *t;
int r;
assert(p);
assert(*p);
assert(c);
t = *p;
if (*t == 0) {
/* If no time is specified at all, but a date of some
* kind, then this means 00:00:00 */
if (c->day || c->weekdays_bits > 0)
goto null_hour;
goto finish;
}
r = parse_chain(&t, false, &h);
if (r < 0)
goto fail;
if (*t != ':') {
r = -EINVAL;
goto fail;
}
t++;
r = parse_chain(&t, false, &m);
if (r < 0)
goto fail;
/* Already at the end? Then it's hours and minutes, and seconds are 0 */
if (*t == 0) {
if (m != NULL)
goto null_second;
goto finish;
}
if (*t != ':') {
r = -EINVAL;
goto fail;
}
t++;
r = parse_chain(&t, true, &s);
if (r < 0)
goto fail;
/* At the end? Then it's hours, minutes and seconds */
if (*t == 0)
goto finish;
r = -EINVAL;
goto fail;
null_hour:
r = const_chain(0, &h);
if (r < 0)
goto fail;
r = const_chain(0, &m);
if (r < 0)
goto fail;
null_second:
r = const_chain(0, &s);
if (r < 0)
goto fail;
finish:
*p = t;
c->hour = h;
c->minute = m;
c->microsecond = s;
return 0;
fail:
free_chain(h);
free_chain(m);
free_chain(s);
return r;
}
int calendar_spec_from_string(const char *p, CalendarSpec **spec) {
CalendarSpec *c;
int r;
const char *utc;
assert(p);
assert(spec);
if (isempty(p))
return -EINVAL;
c = new0(CalendarSpec, 1);
if (!c)
return -ENOMEM;
utc = endswith_no_case(p, " UTC");
if (utc) {
c->utc = true;
p = strndupa(p, utc - p);
}
if (strcaseeq(p, "minutely")) {
r = const_chain(0, &c->microsecond);
if (r < 0)
goto fail;
} else if (strcaseeq(p, "hourly")) {
r = const_chain(0, &c->minute);
if (r < 0)
goto fail;
r = const_chain(0, &c->microsecond);
if (r < 0)
goto fail;
} else if (strcaseeq(p, "daily")) {
r = const_chain(0, &c->hour);
if (r < 0)
goto fail;
r = const_chain(0, &c->minute);
if (r < 0)
goto fail;
r = const_chain(0, &c->microsecond);
if (r < 0)
goto fail;
} else if (strcaseeq(p, "monthly")) {
r = const_chain(1, &c->day);
if (r < 0)
goto fail;
r = const_chain(0, &c->hour);
if (r < 0)
goto fail;
r = const_chain(0, &c->minute);
if (r < 0)
goto fail;
r = const_chain(0, &c->microsecond);
if (r < 0)
goto fail;
} else if (strcaseeq(p, "annually") ||
strcaseeq(p, "yearly") ||
strcaseeq(p, "anually") /* backwards compatibility */ ) {
r = const_chain(1, &c->month);
if (r < 0)
goto fail;
r = const_chain(1, &c->day);
if (r < 0)
goto fail;
r = const_chain(0, &c->hour);
if (r < 0)
goto fail;
r = const_chain(0, &c->minute);
if (r < 0)
goto fail;
r = const_chain(0, &c->microsecond);
if (r < 0)
goto fail;
} else if (strcaseeq(p, "weekly")) {
c->weekdays_bits = 1;
r = const_chain(0, &c->hour);
if (r < 0)
goto fail;
r = const_chain(0, &c->minute);
if (r < 0)
goto fail;
r = const_chain(0, &c->microsecond);
if (r < 0)
goto fail;
} else if (strcaseeq(p, "quarterly")) {
r = const_chain(1, &c->month);
if (r < 0)
goto fail;
r = const_chain(4, &c->month);
if (r < 0)
goto fail;
r = const_chain(7, &c->month);
if (r < 0)
goto fail;
r = const_chain(10, &c->month);
if (r < 0)
goto fail;
r = const_chain(1, &c->day);
if (r < 0)
goto fail;
r = const_chain(0, &c->hour);
if (r < 0)
goto fail;
r = const_chain(0, &c->minute);
if (r < 0)
goto fail;
r = const_chain(0, &c->microsecond);
if (r < 0)
goto fail;
} else if (strcaseeq(p, "biannually") ||
strcaseeq(p, "bi-annually") ||
strcaseeq(p, "semiannually") ||
strcaseeq(p, "semi-annually")) {
r = const_chain(1, &c->month);
if (r < 0)
goto fail;
r = const_chain(7, &c->month);
if (r < 0)
goto fail;
r = const_chain(1, &c->day);
if (r < 0)
goto fail;
r = const_chain(0, &c->hour);
if (r < 0)
goto fail;
r = const_chain(0, &c->minute);
if (r < 0)
goto fail;
r = const_chain(0, &c->microsecond);
if (r < 0)
goto fail;
} else {
r = parse_weekdays(&p, c);
if (r < 0)
goto fail;
r = parse_date(&p, c);
if (r < 0)
goto fail;
r = parse_calendar_time(&p, c);
if (r < 0)
goto fail;
if (*p != 0) {
r = -EINVAL;
goto fail;
}
}
r = calendar_spec_normalize(c);
if (r < 0)
goto fail;
if (!calendar_spec_valid(c)) {
r = -EINVAL;
goto fail;
}
*spec = c;
return 0;
fail:
calendar_spec_free(c);
return r;
}
static int find_matching_component(const CalendarComponent *c, int *val) {
const CalendarComponent *n;
int d = -1;
bool d_set = false;
int r;
assert(val);
if (!c)
return 0;
while (c) {
n = c->next;
if (c->value >= *val) {
if (!d_set || c->value < d) {
d = c->value;
d_set = true;
}
} else if (c->repeat > 0) {
int k;
k = c->value + c->repeat * ((*val - c->value + c->repeat -1) / c->repeat);
if (!d_set || k < d) {
d = k;
d_set = true;
}
}
c = n;
}
if (!d_set)
return -ENOENT;
r = *val != d;
*val = d;
return r;
}
static bool tm_out_of_bounds(const struct tm *tm, bool utc) {
struct tm t;
assert(tm);
t = *tm;
if (mktime_or_timegm(&t, utc) == (time_t) -1)
return true;
/* Did any normalization take place? If so, it was out of bounds before */
return
t.tm_year != tm->tm_year ||
t.tm_mon != tm->tm_mon ||
t.tm_mday != tm->tm_mday ||
t.tm_hour != tm->tm_hour ||
t.tm_min != tm->tm_min ||
t.tm_sec != tm->tm_sec;
}
static bool matches_weekday(int weekdays_bits, const struct tm *tm, bool utc) {
struct tm t;
int k;
if (weekdays_bits < 0 || weekdays_bits >= BITS_WEEKDAYS)
return true;
t = *tm;
if (mktime_or_timegm(&t, utc) == (time_t) -1)
return false;
k = t.tm_wday == 0 ? 6 : t.tm_wday - 1;
return (weekdays_bits & (1 << k));
}
static int find_next(const CalendarSpec *spec, struct tm *tm, usec_t *usec) {
struct tm c;
int tm_usec;
int r;
assert(spec);
assert(tm);
c = *tm;
tm_usec = *usec;
for (;;) {
/* Normalize the current date */
(void) mktime_or_timegm(&c, spec->utc);
c.tm_isdst = -1;
c.tm_year += 1900;
r = find_matching_component(spec->year, &c.tm_year);
c.tm_year -= 1900;
if (r > 0) {
c.tm_mon = 0;
c.tm_mday = 1;
c.tm_hour = c.tm_min = c.tm_sec = tm_usec = 0;
}
if (r < 0 || tm_out_of_bounds(&c, spec->utc))
return r;
c.tm_mon += 1;
r = find_matching_component(spec->month, &c.tm_mon);
c.tm_mon -= 1;
if (r > 0) {
c.tm_mday = 1;
c.tm_hour = c.tm_min = c.tm_sec = tm_usec = 0;
}
if (r < 0 || tm_out_of_bounds(&c, spec->utc)) {
c.tm_year ++;
c.tm_mon = 0;
c.tm_mday = 1;
c.tm_hour = c.tm_min = c.tm_sec = tm_usec = 0;
continue;
}
r = find_matching_component(spec->day, &c.tm_mday);
if (r > 0)
c.tm_hour = c.tm_min = c.tm_sec = tm_usec = 0;
if (r < 0 || tm_out_of_bounds(&c, spec->utc)) {
c.tm_mon ++;
c.tm_mday = 1;
c.tm_hour = c.tm_min = c.tm_sec = tm_usec = 0;
continue;
}
if (!matches_weekday(spec->weekdays_bits, &c, spec->utc)) {
c.tm_mday++;
c.tm_hour = c.tm_min = c.tm_sec = tm_usec = 0;
continue;
}
r = find_matching_component(spec->hour, &c.tm_hour);
if (r > 0)
c.tm_min = c.tm_sec = 0;
if (r < 0 || tm_out_of_bounds(&c, spec->utc)) {
c.tm_mday ++;
c.tm_hour = c.tm_min = c.tm_sec = tm_usec = 0;
continue;
}
r = find_matching_component(spec->minute, &c.tm_min);
if (r > 0)
c.tm_sec = 0;
if (r < 0 || tm_out_of_bounds(&c, spec->utc)) {
c.tm_hour ++;
c.tm_min = c.tm_sec = tm_usec = 0;
continue;
}
c.tm_sec = c.tm_sec * USEC_PER_SEC + tm_usec;
r = find_matching_component(spec->microsecond, &c.tm_sec);
tm_usec = c.tm_sec % USEC_PER_SEC;
c.tm_sec /= USEC_PER_SEC;
if (r < 0 || tm_out_of_bounds(&c, spec->utc)) {
c.tm_min ++;
c.tm_sec = tm_usec = 0;
continue;
}
*tm = c;
*usec = tm_usec;
return 0;
}
}
int calendar_spec_next_usec(const CalendarSpec *spec, usec_t usec, usec_t *next) {
struct tm tm;
time_t t;
int r;
usec_t tm_usec;
assert(spec);
assert(next);
usec++;
t = (time_t) (usec / USEC_PER_SEC);
assert_se(localtime_or_gmtime_r(&t, &tm, spec->utc));
tm_usec = usec % USEC_PER_SEC;
r = find_next(spec, &tm, &tm_usec);
if (r < 0)
return r;
t = mktime_or_timegm(&tm, spec->utc);
if (t == (time_t) -1)
return -EINVAL;
*next = (usec_t) t * USEC_PER_SEC + tm_usec;
return 0;
}
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