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-rw-r--r--src/shared/calendarspec.c1435
1 files changed, 1435 insertions, 0 deletions
diff --git a/src/shared/calendarspec.c b/src/shared/calendarspec.c
new file mode 100644
index 0000000..039080f
--- /dev/null
+++ b/src/shared/calendarspec.c
@@ -0,0 +1,1435 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <ctype.h>
+#include <errno.h>
+#include <limits.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "calendarspec.h"
+#include "errno-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "macro.h"
+#include "memstream-util.h"
+#include "parse-util.h"
+#include "process-util.h"
+#include "sort-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "time-util.h"
+
+#define BITS_WEEKDAYS 127
+#define MIN_YEAR 1970
+#define MAX_YEAR 2199
+
+/* An arbitrary limit on the length of the chains of components. We don't want to
+ * build a very long linked list, which would be slow to iterate over and might cause
+ * our stack to overflow. It's unlikely that legitimate uses require more than a few
+ * linked components anyway. */
+#define CALENDARSPEC_COMPONENTS_MAX 240
+
+/* Let's make sure that the microsecond component is safe to be stored in an 'int' */
+assert_cc(INT_MAX >= USEC_PER_SEC);
+
+static CalendarComponent* chain_free(CalendarComponent *c) {
+ while (c) {
+ CalendarComponent *n = c->next;
+ free_and_replace(c, n);
+ }
+ return NULL;
+}
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(CalendarComponent*, chain_free);
+
+CalendarSpec* calendar_spec_free(CalendarSpec *c) {
+
+ if (!c)
+ return NULL;
+
+ chain_free(c->year);
+ chain_free(c->month);
+ chain_free(c->day);
+ chain_free(c->hour);
+ chain_free(c->minute);
+ chain_free(c->microsecond);
+ free(c->timezone);
+
+ return mfree(c);
+}
+
+static int component_compare(CalendarComponent * const *a, CalendarComponent * const *b) {
+ int r;
+
+ r = CMP((*a)->start, (*b)->start);
+ if (r != 0)
+ return r;
+
+ r = CMP((*a)->stop, (*b)->stop);
+ if (r != 0)
+ return r;
+
+ return CMP((*a)->repeat, (*b)->repeat);
+}
+
+static void normalize_chain(CalendarComponent **c) {
+ assert(c);
+
+ size_t n = 0;
+ for (CalendarComponent *i = *c; i; i = i->next) {
+ n++;
+
+ /* While we're counting the chain, also normalize 'stop'
+ * so the length of the range is a multiple of 'repeat'. */
+ if (i->stop > i->start && i->repeat > 0)
+ i->stop -= (i->stop - i->start) % i->repeat;
+
+ /* If a repeat value is specified, but it cannot even be triggered once, let's suppress it.
+ *
+ * Similarly, if the stop value is the same as the start value, then let's just make this a
+ * non-repeating chain element. */
+ if ((i->stop > i->start && i->repeat > 0 && i->start + i->repeat > i->stop) ||
+ i->start == i->stop) {
+ i->repeat = 0;
+ i->stop = -1;
+ }
+ }
+
+ if (n <= 1)
+ return;
+
+ CalendarComponent **b, **j;
+ b = j = newa(CalendarComponent*, n);
+ for (CalendarComponent *i = *c; i; i = i->next)
+ *(j++) = i;
+
+ typesafe_qsort(b, n, component_compare);
+
+ b[n-1]->next = NULL;
+ CalendarComponent *next = b[n-1];
+
+ /* Drop non-unique entries */
+ for (size_t k = n-1; k > 0; k--) {
+ if (component_compare(&b[k-1], &next) == 0) {
+ 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) {
+ if (c->start >= 0 && c->start < 70)
+ c->start += 2000;
+
+ if (c->stop >= 0 && c->stop < 70)
+ c->stop += 2000;
+
+ if (c->start >= 70 && c->start < 100)
+ c->start += 1900;
+
+ if (c->stop >= 70 && c->stop < 100)
+ c->stop += 1900;
+
+ c = c->next;
+ }
+}
+
+static void calendar_spec_normalize(CalendarSpec *c) {
+ assert(c);
+
+ if (streq_ptr(c->timezone, "UTC")) {
+ c->utc = true;
+ c->timezone = mfree(c->timezone);
+ }
+
+ if (c->weekdays_bits <= 0 || c->weekdays_bits >= BITS_WEEKDAYS)
+ c->weekdays_bits = -1;
+
+ if (c->end_of_month && !c->day)
+ c->end_of_month = false;
+
+ fix_year(c->year);
+
+ normalize_chain(&c->year);
+ normalize_chain(&c->month);
+ normalize_chain(&c->day);
+ normalize_chain(&c->hour);
+ normalize_chain(&c->minute);
+ normalize_chain(&c->microsecond);
+}
+
+static bool chain_valid(CalendarComponent *c, int from, int to, bool end_of_month) {
+ assert(to >= from);
+
+ if (!c)
+ return true;
+
+ /* Forbid dates more than 28 days from the end of the month */
+ if (end_of_month)
+ to -= 3;
+
+ if (c->start < from || c->start > to)
+ return false;
+
+ /* Avoid overly large values that could cause overflow */
+ if (c->repeat > to - from)
+ return false;
+
+ /*
+ * c->repeat must be short enough so at least one repetition may
+ * occur before the end of the interval. For dates scheduled
+ * relative to the end of the month, c->start and c->stop
+ * correspond to the Nth last day of the month.
+ */
+ if (c->stop >= 0) {
+ if (c->stop < from || c ->stop > to)
+ return false;
+
+ if (c->start + c->repeat > c->stop)
+ return false;
+ } else {
+ if (end_of_month && c->start - c->repeat < from)
+ return false;
+
+ if (!end_of_month && c->start + c->repeat > to)
+ return false;
+ }
+
+ if (c->next)
+ return chain_valid(c->next, from, to, end_of_month);
+
+ return true;
+}
+
+_pure_ bool calendar_spec_valid(CalendarSpec *c) {
+ assert(c);
+
+ if (c->weekdays_bits > BITS_WEEKDAYS)
+ return false;
+
+ if (!chain_valid(c->year, MIN_YEAR, MAX_YEAR, false))
+ return false;
+
+ if (!chain_valid(c->month, 1, 12, false))
+ return false;
+
+ if (!chain_valid(c->day, 1, 31, c->end_of_month))
+ return false;
+
+ if (!chain_valid(c->hour, 0, 23, false))
+ return false;
+
+ if (!chain_valid(c->minute, 0, 59, false))
+ return false;
+
+ if (!chain_valid(c->microsecond, 0, 60*USEC_PER_SEC-1, false))
+ 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_comma = 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_comma)
+ fputc(',', f);
+ else
+ need_comma = true;
+
+ fputs(days[x], f);
+ l = x;
+ }
+
+ } else if (l >= 0) {
+
+ if (x > l + 1) {
+ fputs(x > l + 2 ? ".." : ",", f);
+ fputs(days[x-1], f);
+ }
+
+ l = -1;
+ }
+ }
+
+ if (l >= 0 && x > l + 1) {
+ fputs(x > l + 2 ? ".." : ",", f);
+ fputs(days[x-1], f);
+ }
+}
+
+static bool chain_is_star(const CalendarComponent *c, bool usec) {
+ /* Return true if the whole chain can be replaced by '*'.
+ * This happens when the chain is empty or one of the components covers all. */
+ if (!c)
+ return true;
+ if (usec)
+ for (; c; c = c->next)
+ if (c->start == 0 && c->stop < 0 && c->repeat == USEC_PER_SEC)
+ return true;
+ return false;
+}
+
+static void _format_chain(FILE *f, int space, const CalendarComponent *c, bool start, bool usec) {
+ int d = usec ? (int) USEC_PER_SEC : 1;
+
+ assert(f);
+
+ if (start && chain_is_star(c, usec)) {
+ fputc('*', f);
+ return;
+ }
+
+ assert(c->start >= 0);
+
+ fprintf(f, "%0*i", space, c->start / d);
+ if (c->start % d > 0)
+ fprintf(f, ".%06i", c->start % d);
+
+ if (c->stop > 0)
+ fprintf(f, "..%0*i", space, c->stop / d);
+ if (c->stop % d > 0)
+ fprintf(f, ".%06i", c->stop % d);
+
+ if (c->repeat > 0 && !(c->stop > 0 && c->repeat == d))
+ fprintf(f, "/%i", c->repeat / d);
+ if (c->repeat % d > 0)
+ fprintf(f, ".%06i", c->repeat % d);
+
+ if (c->next) {
+ fputc(',', f);
+ _format_chain(f, space, c->next, false, usec);
+ }
+}
+
+static void format_chain(FILE *f, int space, const CalendarComponent *c, bool usec) {
+ _format_chain(f, space, c, /* start = */ true, usec);
+}
+
+int calendar_spec_to_string(const CalendarSpec *c, char **ret) {
+ _cleanup_(memstream_done) MemStream m = {};
+ FILE *f;
+
+ assert(c);
+ assert(ret);
+
+ f = memstream_init(&m);
+ 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(c->end_of_month ? '~' : '-', 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);
+ else if (c->timezone) {
+ fputc(' ', f);
+ fputs(c->timezone, f);
+ } else if (IN_SET(c->dst, 0, 1)) {
+
+ /* If daylight saving is explicitly on or off, let's show the used timezone. */
+
+ tzset();
+
+ if (!isempty(tzname[c->dst])) {
+ fputc(' ', f);
+ fputs(tzname[c->dst], f);
+ }
+ }
+
+ return memstream_finalize(&m, ret, NULL);
+}
+
+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 (;;) {
+ size_t i;
+
+ 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 (!IN_SET((*p)[skip], 0, '-', '.', ',', ' '))
+ return -EINVAL;
+
+ c->weekdays_bits |= 1 << day_nr[i].nr;
+
+ if (l >= 0) {
+ if (l > day_nr[i].nr)
+ return -EINVAL;
+
+ for (int 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;
+
+ if ((*p)[1] != '.')
+ return -EINVAL;
+
+ l = day_nr[i].nr;
+ *p += 2;
+
+ /* Support ranges with "-" for backwards compatibility */
+ } else if (**p == '-') {
+ if (l >= 0)
+ return -EINVAL;
+
+ l = day_nr[i].nr;
+ *p += 1;
+
+ } else if (**p == ',') {
+ l = -1;
+ *p += 1;
+ }
+
+ /* Allow a trailing comma but not an open range */
+ if (IN_SET(**p, 0, ' ')) {
+ *p += strspn(*p, " ");
+ return l < 0 ? 0 : -EINVAL;
+ }
+
+ first = false;
+ }
+}
+
+static int parse_one_number(const char *p, const char **e, unsigned long *ret) {
+ char *ee = NULL;
+ unsigned long value;
+
+ errno = 0;
+ value = strtoul(p, &ee, 10);
+ if (errno > 0)
+ return -errno;
+ if (ee == p)
+ return -EINVAL;
+
+ *ret = value;
+ *e = ee;
+ return 0;
+}
+
+static int parse_component_decimal(const char **p, bool usec, int *res) {
+ unsigned long value;
+ const char *e = NULL;
+ int r;
+
+ if (!ascii_isdigit(**p))
+ return -EINVAL;
+
+ r = parse_one_number(*p, &e, &value);
+ if (r < 0)
+ return r;
+
+ if (usec) {
+ if (value * USEC_PER_SEC / USEC_PER_SEC != value)
+ return -ERANGE;
+
+ value *= USEC_PER_SEC;
+
+ /* One "." is a decimal point, but ".." is a range separator */
+ if (e[0] == '.' && e[1] != '.') {
+ unsigned add;
+
+ e++;
+ r = parse_fractional_part_u(&e, 6, &add);
+ if (r < 0)
+ return r;
+
+ if (add + value < value)
+ return -ERANGE;
+ value += add;
+ }
+ }
+
+ if (value > INT_MAX)
+ return -ERANGE;
+
+ *p = e;
+ *res = value;
+
+ return 0;
+}
+
+static int const_chain(int value, CalendarComponent **c) {
+ CalendarComponent *cc = NULL;
+
+ assert(c);
+
+ cc = new(CalendarComponent, 1);
+ if (!cc)
+ return -ENOMEM;
+
+ *cc = (CalendarComponent) {
+ .start = value,
+ .stop = -1,
+ .repeat = 0,
+ .next = *c,
+ };
+
+ *c = cc;
+
+ return 0;
+}
+
+static int calendarspec_from_time_t(CalendarSpec *c, time_t time) {
+ _cleanup_(chain_freep) CalendarComponent
+ *year = NULL, *month = NULL, *day = NULL,
+ *hour = NULL, *minute = NULL, *us = NULL;
+ struct tm tm;
+ int r;
+
+ if (!gmtime_r(&time, &tm))
+ return -ERANGE;
+
+ if (tm.tm_year > INT_MAX - 1900)
+ return -ERANGE;
+
+ r = const_chain(tm.tm_year + 1900, &year);
+ if (r < 0)
+ return r;
+
+ r = const_chain(tm.tm_mon + 1, &month);
+ if (r < 0)
+ return r;
+
+ r = const_chain(tm.tm_mday, &day);
+ if (r < 0)
+ return r;
+
+ r = const_chain(tm.tm_hour, &hour);
+ if (r < 0)
+ return r;
+
+ r = const_chain(tm.tm_min, &minute);
+ if (r < 0)
+ return r;
+
+ r = const_chain(tm.tm_sec * USEC_PER_SEC, &us);
+ if (r < 0)
+ return r;
+
+ c->utc = true;
+ c->year = TAKE_PTR(year);
+ c->month = TAKE_PTR(month);
+ c->day = TAKE_PTR(day);
+ c->hour = TAKE_PTR(hour);
+ c->minute = TAKE_PTR(minute);
+ c->microsecond = TAKE_PTR(us);
+ return 0;
+}
+
+static int prepend_component(const char **p, bool usec, unsigned nesting, CalendarComponent **c) {
+ int r, start, stop = -1, repeat = 0;
+ CalendarComponent *cc;
+ const char *e = *p;
+
+ assert(p);
+ assert(c);
+
+ if (nesting > CALENDARSPEC_COMPONENTS_MAX)
+ return -ENOBUFS;
+
+ r = parse_component_decimal(&e, usec, &start);
+ if (r < 0)
+ return r;
+
+ if (e[0] == '.' && e[1] == '.') {
+ e += 2;
+ r = parse_component_decimal(&e, usec, &stop);
+ if (r < 0)
+ return r;
+
+ repeat = usec ? USEC_PER_SEC : 1;
+ }
+
+ if (*e == '/') {
+ e++;
+ r = parse_component_decimal(&e, usec, &repeat);
+ if (r < 0)
+ return r;
+
+ if (repeat == 0)
+ return -ERANGE;
+ } else {
+ /* If no repeat value is specified for the μs component, then let's explicitly refuse ranges
+ * below 1s because our default repeat granularity is beyond that. */
+
+ /* Overflow check */
+ if (start > INT_MAX - repeat)
+ return -ERANGE;
+
+ if (usec && stop >= 0 && start + repeat > stop)
+ return -EINVAL;
+ }
+
+ if (!IN_SET(*e, 0, ' ', ',', '-', '~', ':'))
+ return -EINVAL;
+
+ cc = new(CalendarComponent, 1);
+ if (!cc)
+ return -ENOMEM;
+
+ *cc = (CalendarComponent) {
+ .start = start,
+ .stop = stop,
+ .repeat = repeat,
+ .next = *c,
+ };
+
+ *p = e;
+ *c = cc;
+
+ if (*e ==',') {
+ *p += 1;
+ return prepend_component(p, usec, nesting + 1, c);
+ }
+
+ return 0;
+}
+
+static int parse_chain(const char **p, bool usec, CalendarComponent **c) {
+ _cleanup_(chain_freep) CalendarComponent *cc = NULL;
+ const char *t;
+ 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, 0, &cc);
+ if (r < 0)
+ return r;
+
+ *p = t;
+ *c = TAKE_PTR(cc);
+ return 0;
+}
+
+static int parse_date(const char **p, CalendarSpec *c) {
+ _cleanup_(chain_freep) CalendarComponent *first = NULL, *second = NULL, *third = NULL;
+ const char *t;
+ int r;
+
+ assert(p);
+ assert(*p);
+ assert(c);
+
+ t = *p;
+
+ if (*t == 0)
+ return 0;
+
+ /* @TIMESTAMP — UNIX time in seconds since the epoch */
+ if (*t == '@') {
+ unsigned long value;
+ time_t time;
+
+ r = parse_one_number(t + 1, &t, &value);
+ if (r < 0)
+ return r;
+
+ time = value;
+ if ((unsigned long) time != value)
+ return -ERANGE;
+
+ r = calendarspec_from_time_t(c, time);
+ if (r < 0)
+ return r;
+
+ *p = t;
+ return 1; /* finito, don't parse H:M:S after that */
+ }
+
+ 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 (IN_SET(*t, 0, ':'))
+ return 0;
+
+ if (*t == '~')
+ c->end_of_month = true;
+ else if (*t != '-')
+ return -EINVAL;
+
+ t++;
+ r = parse_chain(&t, false, &second);
+ if (r < 0)
+ return r;
+
+ /* Got two parts, hence it's month and day */
+ if (IN_SET(*t, 0, ' ')) {
+ *p = t + strspn(t, " ");
+ c->month = TAKE_PTR(first);
+ c->day = TAKE_PTR(second);
+ return 0;
+ } else if (c->end_of_month)
+ return -EINVAL;
+
+ if (*t == '~')
+ c->end_of_month = true;
+ else if (*t != '-')
+ return -EINVAL;
+
+ t++;
+ r = parse_chain(&t, false, &third);
+ if (r < 0)
+ return r;
+
+ if (!IN_SET(*t, 0, ' '))
+ return -EINVAL;
+
+ /* Got three parts, hence it is year, month and day */
+ *p = t + strspn(t, " ");
+ c->year = TAKE_PTR(first);
+ c->month = TAKE_PTR(second);
+ c->day = TAKE_PTR(third);
+ return 0;
+}
+
+static int parse_calendar_time(const char **p, CalendarSpec *c) {
+ _cleanup_(chain_freep) CalendarComponent *h = NULL, *m = NULL, *s = NULL;
+ const char *t;
+ int r;
+
+ assert(p);
+ assert(*p);
+ assert(c);
+
+ t = *p;
+
+ /* If no time is specified at all, then this means 00:00:00 */
+ if (*t == 0)
+ goto null_hour;
+
+ r = parse_chain(&t, false, &h);
+ if (r < 0)
+ return r;
+
+ if (*t != ':')
+ return -EINVAL;
+
+ t++;
+ r = parse_chain(&t, false, &m);
+ if (r < 0)
+ return r;
+
+ /* Already at the end? Then it's hours and minutes, and seconds are 0 */
+ if (*t == 0)
+ goto null_second;
+
+ if (*t != ':')
+ return -EINVAL;
+
+ t++;
+ r = parse_chain(&t, true, &s);
+ if (r < 0)
+ return r;
+
+ /* At the end? Then it's hours, minutes and seconds */
+ if (*t == 0)
+ goto finish;
+
+ return -EINVAL;
+
+null_hour:
+ r = const_chain(0, &h);
+ if (r < 0)
+ return r;
+
+ r = const_chain(0, &m);
+ if (r < 0)
+ return r;
+
+null_second:
+ r = const_chain(0, &s);
+ if (r < 0)
+ return r;
+
+finish:
+ *p = t;
+ c->hour = TAKE_PTR(h);
+ c->minute = TAKE_PTR(m);
+ c->microsecond = TAKE_PTR(s);
+
+ return 0;
+}
+
+int calendar_spec_from_string(const char *p, CalendarSpec **ret) {
+ const char *utc;
+ _cleanup_(calendar_spec_freep) CalendarSpec *c = NULL;
+ _cleanup_free_ char *p_tmp = NULL;
+ int r;
+
+ assert(p);
+
+ c = new(CalendarSpec, 1);
+ if (!c)
+ return -ENOMEM;
+
+ *c = (CalendarSpec) {
+ .dst = -1,
+ .timezone = NULL,
+ };
+
+ utc = endswith_no_case(p, " UTC");
+ if (utc) {
+ c->utc = true;
+ p = p_tmp = strndup(p, utc - p);
+ if (!p)
+ return -ENOMEM;
+ } else {
+ const char *e = NULL;
+ int j;
+
+ tzset();
+
+ /* Check if the local timezone was specified? */
+ for (j = 0; j <= 1; j++) {
+ if (isempty(tzname[j]))
+ continue;
+
+ e = endswith_no_case(p, tzname[j]);
+ if (!e)
+ continue;
+ if (e == p)
+ continue;
+ if (e[-1] != ' ')
+ continue;
+
+ break;
+ }
+
+ /* Found one of the two timezones specified? */
+ if (IN_SET(j, 0, 1)) {
+ p = p_tmp = strndup(p, e - p - 1);
+ if (!p)
+ return -ENOMEM;
+
+ c->dst = j;
+ } else {
+ const char *last_space;
+
+ last_space = strrchr(p, ' ');
+ if (last_space != NULL && timezone_is_valid(last_space + 1, LOG_DEBUG)) {
+ c->timezone = strdup(last_space + 1);
+ if (!c->timezone)
+ return -ENOMEM;
+
+ p = p_tmp = strndup(p, last_space - p);
+ if (!p)
+ return -ENOMEM;
+ }
+ }
+ }
+
+ if (isempty(p))
+ return -EINVAL;
+
+ if (strcaseeq(p, "minutely")) {
+ r = const_chain(0, &c->microsecond);
+ if (r < 0)
+ return r;
+
+ } else if (strcaseeq(p, "hourly")) {
+ r = const_chain(0, &c->minute);
+ if (r < 0)
+ return r;
+ r = const_chain(0, &c->microsecond);
+ if (r < 0)
+ return r;
+
+ } else if (strcaseeq(p, "daily")) {
+ r = const_chain(0, &c->hour);
+ if (r < 0)
+ return r;
+ r = const_chain(0, &c->minute);
+ if (r < 0)
+ return r;
+ r = const_chain(0, &c->microsecond);
+ if (r < 0)
+ return r;
+
+ } else if (strcaseeq(p, "monthly")) {
+ r = const_chain(1, &c->day);
+ if (r < 0)
+ return r;
+ r = const_chain(0, &c->hour);
+ if (r < 0)
+ return r;
+ r = const_chain(0, &c->minute);
+ if (r < 0)
+ return r;
+ r = const_chain(0, &c->microsecond);
+ if (r < 0)
+ return r;
+
+ } else if (STRCASE_IN_SET(p,
+ "annually",
+ "yearly",
+ "anually") /* backwards compatibility */ ) {
+
+ r = const_chain(1, &c->month);
+ if (r < 0)
+ return r;
+ r = const_chain(1, &c->day);
+ if (r < 0)
+ return r;
+ r = const_chain(0, &c->hour);
+ if (r < 0)
+ return r;
+ r = const_chain(0, &c->minute);
+ if (r < 0)
+ return r;
+ r = const_chain(0, &c->microsecond);
+ if (r < 0)
+ return r;
+
+ } else if (strcaseeq(p, "weekly")) {
+
+ c->weekdays_bits = 1;
+
+ r = const_chain(0, &c->hour);
+ if (r < 0)
+ return r;
+ r = const_chain(0, &c->minute);
+ if (r < 0)
+ return r;
+ r = const_chain(0, &c->microsecond);
+ if (r < 0)
+ return r;
+
+ } else if (strcaseeq(p, "quarterly")) {
+
+ r = const_chain(1, &c->month);
+ if (r < 0)
+ return r;
+ r = const_chain(4, &c->month);
+ if (r < 0)
+ return r;
+ r = const_chain(7, &c->month);
+ if (r < 0)
+ return r;
+ r = const_chain(10, &c->month);
+ if (r < 0)
+ return r;
+ r = const_chain(1, &c->day);
+ if (r < 0)
+ return r;
+ r = const_chain(0, &c->hour);
+ if (r < 0)
+ return r;
+ r = const_chain(0, &c->minute);
+ if (r < 0)
+ return r;
+ r = const_chain(0, &c->microsecond);
+ if (r < 0)
+ return r;
+
+ } else if (STRCASE_IN_SET(p,
+ "biannually",
+ "bi-annually",
+ "semiannually",
+ "semi-annually")) {
+
+ r = const_chain(1, &c->month);
+ if (r < 0)
+ return r;
+ r = const_chain(7, &c->month);
+ if (r < 0)
+ return r;
+ r = const_chain(1, &c->day);
+ if (r < 0)
+ return r;
+ r = const_chain(0, &c->hour);
+ if (r < 0)
+ return r;
+ r = const_chain(0, &c->minute);
+ if (r < 0)
+ return r;
+ r = const_chain(0, &c->microsecond);
+ if (r < 0)
+ return r;
+
+ } else {
+ r = parse_weekdays(&p, c);
+ if (r < 0)
+ return r;
+
+ r = parse_date(&p, c);
+ if (r < 0)
+ return r;
+
+ if (r == 0) {
+ r = parse_calendar_time(&p, c);
+ if (r < 0)
+ return r;
+ }
+
+ if (*p != 0)
+ return -EINVAL;
+ }
+
+ calendar_spec_normalize(c);
+
+ if (!calendar_spec_valid(c))
+ return -EINVAL;
+
+ if (ret)
+ *ret = TAKE_PTR(c);
+ return 0;
+}
+
+static int find_end_of_month(const struct tm *tm, bool utc, int day) {
+ struct tm t = *tm;
+
+ t.tm_mon++;
+ t.tm_mday = 1 - day;
+
+ if (mktime_or_timegm(&t, utc) < 0 ||
+ t.tm_mon != tm->tm_mon)
+ return -1;
+
+ return t.tm_mday;
+}
+
+static int find_matching_component(
+ const CalendarSpec *spec,
+ const CalendarComponent *c,
+ const struct tm *tm, /* tm is only used for end-of-month calculations */
+ int *val) {
+
+ int d = -1, r;
+ bool d_set = false;
+
+ assert(val);
+
+ /* Finds the *earliest* matching time specified by one of the CalendarCompoment items in chain c.
+ * If no matches can be found, returns -ENOENT.
+ * Otherwise, updates *val to the matching time. 1 is returned if *val was changed, 0 otherwise.
+ */
+
+ if (!c)
+ return 0;
+
+ bool end_of_month = spec->end_of_month && c == spec->day;
+
+ while (c) {
+ int start, stop;
+
+ if (end_of_month) {
+ start = find_end_of_month(tm, spec->utc, c->start);
+ stop = find_end_of_month(tm, spec->utc, c->stop);
+
+ if (stop > 0)
+ SWAP_TWO(start, stop);
+ } else {
+ start = c->start;
+ stop = c->stop;
+ }
+
+ if (start >= *val) {
+
+ if (!d_set || start < d) {
+ d = start;
+ d_set = true;
+ }
+
+ } else if (c->repeat > 0) {
+ int k;
+
+ k = start + ROUND_UP(*val - start, c->repeat);
+
+ if ((!d_set || k < d) && (stop < 0 || k <= stop)) {
+ d = k;
+ d_set = true;
+ }
+ }
+
+ c = c->next;
+ }
+
+ if (!d_set)
+ return -ENOENT;
+
+ r = *val != d;
+ *val = d;
+ return r;
+}
+
+static int tm_within_bounds(struct tm *tm, bool utc) {
+ struct tm t;
+ int cmp;
+ assert(tm);
+
+ /*
+ * Set an upper bound on the year so impossible dates like "*-02-31"
+ * don't cause find_next() to loop forever. tm_year contains years
+ * since 1900, so adjust it accordingly.
+ */
+ if (tm->tm_year + 1900 > MAX_YEAR)
+ return -ERANGE;
+
+ t = *tm;
+ if (mktime_or_timegm(&t, utc) < 0)
+ return negative_errno();
+
+ /*
+ * Did any normalization take place? If so, it was out of bounds before.
+ * Normalization could skip next elapse, e.g. result of normalizing 3-33
+ * is 4-2. This skips 4-1. So reset the sub time unit if upper unit was
+ * out of bounds. Normalization has occurred implies find_matching_component() > 0,
+ * other sub time units are already reset in find_next().
+ */
+ if ((cmp = CMP(t.tm_year, tm->tm_year)) != 0)
+ t.tm_mon = 0;
+ else if ((cmp = CMP(t.tm_mon, tm->tm_mon)) != 0)
+ t.tm_mday = 1;
+ else if ((cmp = CMP(t.tm_mday, tm->tm_mday)) != 0)
+ t.tm_hour = 0;
+ else if ((cmp = CMP(t.tm_hour, tm->tm_hour)) != 0)
+ t.tm_min = 0;
+ else if ((cmp = CMP(t.tm_min, tm->tm_min)) != 0)
+ t.tm_sec = 0;
+ else
+ cmp = CMP(t.tm_sec, tm->tm_sec);
+
+ if (cmp < 0)
+ return -EDEADLK; /* Refuse to go backward */
+ if (cmp > 0)
+ *tm = t;
+ return cmp == 0;
+}
+
+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) < 0)
+ return false;
+
+ k = t.tm_wday == 0 ? 6 : t.tm_wday - 1;
+ return (weekdays_bits & (1 << k));
+}
+
+/* A safety valve: if we get stuck in the calculation, return an error.
+ * C.f. https://bugzilla.redhat.com/show_bug.cgi?id=1941335. */
+#define MAX_CALENDAR_ITERATIONS 1000
+
+static int find_next(const CalendarSpec *spec, struct tm *tm, usec_t *usec) {
+ struct tm c;
+ int tm_usec;
+ int r;
+
+ /* Returns -ENOENT if the expression is not going to elapse anymore */
+
+ assert(spec);
+ assert(tm);
+
+ c = *tm;
+ tm_usec = *usec;
+
+ for (unsigned iteration = 0; iteration < MAX_CALENDAR_ITERATIONS; iteration++) {
+ /* Normalize the current date */
+ (void) mktime_or_timegm(&c, spec->utc);
+ c.tm_isdst = spec->dst;
+
+ c.tm_year += 1900;
+ r = find_matching_component(spec, spec->year, &c, &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)
+ return r;
+ if (tm_within_bounds(&c, spec->utc) <= 0)
+ return -ENOENT;
+
+ c.tm_mon += 1;
+ r = find_matching_component(spec, spec->month, &c, &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 || (r = tm_within_bounds(&c, spec->utc)) < 0) {
+ c.tm_year++;
+ c.tm_mon = 0;
+ c.tm_mday = 1;
+ c.tm_hour = c.tm_min = c.tm_sec = tm_usec = 0;
+ continue;
+ }
+ if (r == 0)
+ continue;
+
+ r = find_matching_component(spec, spec->day, &c, &c.tm_mday);
+ if (r > 0)
+ c.tm_hour = c.tm_min = c.tm_sec = tm_usec = 0;
+ if (r < 0 || (r = tm_within_bounds(&c, spec->utc)) < 0) {
+ c.tm_mon++;
+ c.tm_mday = 1;
+ c.tm_hour = c.tm_min = c.tm_sec = tm_usec = 0;
+ continue;
+ }
+ if (r == 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, spec->hour, &c, &c.tm_hour);
+ if (r > 0)
+ c.tm_min = c.tm_sec = tm_usec = 0;
+ if (r < 0 || (r = tm_within_bounds(&c, spec->utc)) < 0) {
+ c.tm_mday++;
+ c.tm_hour = c.tm_min = c.tm_sec = tm_usec = 0;
+ continue;
+ }
+ if (r == 0)
+ /* The next hour we set might be missing if there
+ * are time zone changes. Let's try again starting at
+ * normalized time. */
+ continue;
+
+ r = find_matching_component(spec, spec->minute, &c, &c.tm_min);
+ if (r > 0)
+ c.tm_sec = tm_usec = 0;
+ if (r < 0 || (r = tm_within_bounds(&c, spec->utc)) < 0) {
+ c.tm_hour++;
+ c.tm_min = c.tm_sec = tm_usec = 0;
+ continue;
+ }
+ if (r == 0)
+ continue;
+
+ c.tm_sec = c.tm_sec * USEC_PER_SEC + tm_usec;
+ r = find_matching_component(spec, spec->microsecond, &c, &c.tm_sec);
+ tm_usec = c.tm_sec % USEC_PER_SEC;
+ c.tm_sec /= USEC_PER_SEC;
+
+ if (r < 0 || (r = tm_within_bounds(&c, spec->utc)) < 0) {
+ c.tm_min++;
+ c.tm_sec = tm_usec = 0;
+ continue;
+ }
+ if (r == 0)
+ continue;
+
+ *tm = c;
+ *usec = tm_usec;
+ return 0;
+ }
+
+ /* It seems we entered an infinite loop. Let's gracefully return an error instead of hanging or
+ * aborting. This code is also exercised when timers.target is brought up during early boot, so
+ * aborting here is problematic and hard to diagnose for users. */
+ _cleanup_free_ char *s = NULL;
+ (void) calendar_spec_to_string(spec, &s);
+ return log_warning_errno(SYNTHETIC_ERRNO(EDEADLK),
+ "Infinite loop in calendar calculation: %s", strna(s));
+}
+
+static int calendar_spec_next_usec_impl(const CalendarSpec *spec, usec_t usec, usec_t *ret_next) {
+ struct tm tm;
+ time_t t;
+ int r;
+ usec_t tm_usec;
+
+ assert(spec);
+
+ if (usec > USEC_TIMESTAMP_FORMATTABLE_MAX)
+ return -EINVAL;
+
+ 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 < 0)
+ return -EINVAL;
+
+ if (ret_next)
+ *ret_next = (usec_t) t * USEC_PER_SEC + tm_usec;
+
+ return 0;
+}
+
+typedef struct SpecNextResult {
+ usec_t next;
+ int return_value;
+} SpecNextResult;
+
+int calendar_spec_next_usec(const CalendarSpec *spec, usec_t usec, usec_t *ret_next) {
+ SpecNextResult *shared, tmp;
+ int r;
+
+ assert(spec);
+
+ if (isempty(spec->timezone))
+ return calendar_spec_next_usec_impl(spec, usec, ret_next);
+
+ shared = mmap(NULL, sizeof *shared, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANONYMOUS, -1, 0);
+ if (shared == MAP_FAILED)
+ return negative_errno();
+
+ r = safe_fork("(sd-calendar)", FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_DEATHSIG_SIGKILL|FORK_WAIT, NULL);
+ if (r < 0) {
+ (void) munmap(shared, sizeof *shared);
+ return r;
+ }
+ if (r == 0) {
+ char *colon_tz;
+
+ /* tzset(3) says $TZ should be prefixed with ":" if we reference timezone files */
+ colon_tz = strjoina(":", spec->timezone);
+
+ if (setenv("TZ", colon_tz, 1) != 0) {
+ shared->return_value = negative_errno();
+ _exit(EXIT_FAILURE);
+ }
+
+ tzset();
+
+ shared->return_value = calendar_spec_next_usec_impl(spec, usec, &shared->next);
+
+ _exit(EXIT_SUCCESS);
+ }
+
+ tmp = *shared;
+ if (munmap(shared, sizeof *shared) < 0)
+ return negative_errno();
+
+ if (tmp.return_value == 0 && ret_next)
+ *ret_next = tmp.next;
+
+ return tmp.return_value;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-28 04:11:29 +0000