timer: implement calendar time events

1 files changed, 927 insertions, 0 deletions

diff --git a/src/shared/calendarspec.c b/src/shared/calendarspec.c
new file mode 100644
index 0000000000..3cddb0eed0
--- /dev/null
+++ b/src/shared/calendarspec.c
@@ -0,0 +1,927 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  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 <stdlib.h>
+#include <string.h>
+
+#include "calendarspec.h"
+
+static void free_chain(CalendarComponent *c) {
+        CalendarComponent *n;
+
+        while (c) {
+                n = c->next;
+                free(c);
+                c = n;
+        }
+}
+
+void calendar_spec_free(CalendarSpec *c) {
+        assert(c);
+
+        free_chain(c->year);
+        free_chain(c->month);
+        free_chain(c->day);
+        free_chain(c->hour);
+        free_chain(c->minute);
+        free_chain(c->second);
+
+        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 >= 127)
+                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->second);
+
+        return 0;
+}
+
+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;
+}
+
+bool calendar_spec_valid(CalendarSpec *c) {
+        assert(c);
+
+        if (c->weekdays_bits > 127)
+                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->second, 0, 59))
+                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 <= 127);
+
+        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) {
+        assert(f);
+
+        if (!c) {
+                fputc('*', f);
+                return;
+        }
+
+        assert(c->value >= 0);
+        fprintf(f, "%0*i", space, c->value);
+
+        if (c->repeat > 0)
+                fprintf(f, "/%i", c->repeat);
+
+        if (c->next) {
+                fputc(',', f);
+                format_chain(f, space, c->next);
+        }
+}
+
+int calendar_spec_to_string(const CalendarSpec *c, char **p) {
+        char *buf = NULL;
+        size_t sz = 0;
+        FILE *f;
+
+        assert(c);
+        assert(p);
+
+        f = open_memstream(&buf, &sz);
+        if (!f)
+                return -ENOMEM;
+
+        if (c->weekdays_bits > 0 && c->weekdays_bits <= 127) {
+                format_weekdays(f, c);
+                fputc(' ', f);
+        }
+
+        format_chain(f, 4, c->year);
+        fputc('-', f);
+        format_chain(f, 2, c->month);
+        fputc('-', f);
+        format_chain(f, 2, c->day);
+        fputc(' ', f);
+        format_chain(f, 2, c->hour);
+        fputc(':', f);
+        format_chain(f, 2, c->minute);
+        fputc(':', f);
+        format_chain(f, 2, c->second);
+
+        fflush(f);
+
+        if (ferror(f)) {
+                free(buf);
+                fclose(f);
+                return -ENOMEM;
+        }
+
+        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 prepend_component(const char **p, CalendarComponent **c) {
+        unsigned long value, repeat = 0;
+        char *e = NULL, *ee = NULL;
+        CalendarComponent *cc;
+
+        assert(p);
+        assert(c);
+
+        errno = 0;
+        value = strtoul(*p, &e, 10);
+        if (errno != 0)
+                return -errno;
+        if (e == *p)
+                return -EINVAL;
+        if ((unsigned long) (int) value != value)
+                return -ERANGE;
+
+        if (*e == '/') {
+                repeat = strtoul(e+1, &ee, 10);
+                if (errno != 0)
+                        return -errno;
+                if (ee == e+1)
+                        return -EINVAL;
+                if ((unsigned long) (int) repeat != repeat)
+                        return -ERANGE;
+                if (repeat <= 0)
+                        return -ERANGE;
+
+                e = ee;
+        }
+
+        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, c);
+        }
+
+        return 0;
+}
+
+static int parse_chain(const char **p, CalendarComponent **c) {
+        const char *t;
+        CalendarComponent *cc = NULL;
+        int r;
+
+        assert(p);
+        assert(c);
+
+        t = *p;
+
+        if (t[0] == '*') {
+                *p = t + 1;
+                *c = NULL;
+                return 0;
+        }
+
+        r = prepend_component(&t, &cc);
+        if (r < 0) {
+                free_chain(cc);
+                return r;
+        }
+
+        *p = t;
+        *c = cc;
+        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 = NULL;
+
+        *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, &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, &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, &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_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, &h);
+        if (r < 0)
+                goto fail;
+
+        if (*t != ':') {
+                r = -EINVAL;
+                goto fail;
+        }
+
+        t++;
+        r = parse_chain(&t, &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, &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->second = 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;
+
+        assert(p);
+        assert(spec);
+
+        if (isempty(p))
+                return -EINVAL;
+
+        c = new0(CalendarSpec, 1);
+        if (!c)
+                return -ENOMEM;
+
+        if (strcasecmp(p, "hourly") == 0) {
+                r = const_chain(0, &c->minute);
+                if (r < 0)
+                        goto fail;
+                r = const_chain(0, &c->second);
+                if (r < 0)
+                        goto fail;
+
+        } else if (strcasecmp(p, "daily") == 0) {
+                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->second);
+                if (r < 0)
+                        goto fail;
+
+        } else if (strcasecmp(p, "monthly") == 0) {
+                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->second);
+                if (r < 0)
+                        goto fail;
+
+        } else if (strcasecmp(p, "weekly") == 0) {
+
+                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->second);
+                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_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;
+        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) {
+        struct tm t;
+        assert(tm);
+
+        t = *tm;
+
+        if (mktime(&t) == (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) {
+        struct tm t;
+        int k;
+
+        if (weekdays_bits < 0 || weekdays_bits >= 127)
+                return true;
+
+        t = *tm;
+        if (mktime(&t) == (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) {
+        struct tm c;
+        int r;
+
+        assert(spec);
+        assert(tm);
+
+        c = *tm;
+
+        for (;;) {
+                /* Normalize the current date */
+                mktime(&c);
+                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 = 0;
+                }
+                if (r < 0 || tm_out_of_bounds(&c))
+                        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 = 0;
+                }
+                if (r < 0 || tm_out_of_bounds(&c)) {
+                        c.tm_year ++;
+                        c.tm_mon = 0;
+                        c.tm_mday = 1;
+                        c.tm_hour = c.tm_min = c.tm_sec = 0;
+                        continue;
+                }
+
+                r = find_matching_component(spec->day, &c.tm_mday);
+                if (r > 0)
+                        c.tm_hour = c.tm_min = c.tm_sec = 0;
+                if (r < 0 || tm_out_of_bounds(&c)) {
+                        c.tm_mon ++;
+                        c.tm_mday = 1;
+                        c.tm_hour = c.tm_min = c.tm_sec = 0;
+                        continue;
+                }
+
+                if (!matches_weekday(spec->weekdays_bits, &c)) {
+                        c.tm_mday++;
+                        c.tm_hour = c.tm_min = c.tm_sec = 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)) {
+                        c.tm_mday ++;
+                        c.tm_hour = c.tm_min = c.tm_sec = 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)) {
+                        c.tm_hour ++;
+                        c.tm_min = c.tm_sec = 0;
+                        continue;
+                }
+
+                r = find_matching_component(spec->second, &c.tm_sec);
+                if (r < 0 || tm_out_of_bounds(&c)) {
+                        c.tm_min ++;
+                        c.tm_sec = 0;
+                        continue;
+                }
+
+
+                *tm = c;
+                return 0;
+        }
+}
+
+int calendar_spec_next_usec(const CalendarSpec *spec, usec_t usec, usec_t *next) {
+        struct tm tm;
+        time_t t;
+        int r;
+
+        assert(spec);
+        assert(next);
+
+        t = (time_t) (usec / USEC_PER_SEC) + 1;
+        assert_se(localtime_r(&t, &tm));
+
+        r = find_next(spec, &tm);
+        if (r < 0)
+                return r;
+
+        t = mktime(&tm);
+        if (t == (time_t) -1)
+                return -EINVAL;
+
+
+        *next = (usec_t) t * USEC_PER_SEC;
+        return 0;
+}