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- /*
- Copyright (c) 2013, Matthias Schiffer <mschiffer@universe-factory.net>
- All rights reserved.
-
- Redistribution and use in source and binary forms, with or without
- modification, are permitted provided that the following conditions are met:
-
- 1. Redistributions of source code must retain the above copyright notice,
- this list of conditions and the following disclaimer.
- 2. Redistributions in binary form must reproduce the above copyright notice,
- this list of conditions and the following disclaimer in the documentation
- and/or other materials provided with the distribution.
-
- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
- FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
- SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
- CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-
- #include <sys/types.h>
- #include <sys/time.h>
- #include <dirent.h>
- #include <signal.h>
- #include <stdint.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #include <strings.h>
- #include <syslog.h>
- #include <time.h>
- #include <unistd.h>
-
-
- typedef struct job {
- struct job *next;
-
- uint64_t minutes;
- uint32_t hours;
- uint32_t doms;
- uint16_t months;
- uint8_t dows;
-
- char *command;
- } job_t;
-
-
- static const char const *const MONTHS[12] = {
- "jan", "feb", "mar", "apr", "may", "jun", "jul", "aug", "sep", "oct", "nov", "dec"
- };
-
- static const char const *const WEEKDAYS[7] = {
- "sun", "mon", "tue", "wed", "thu", "fri", "sat"
- };
-
-
- static const char *crondir;
-
- static job_t *jobs = NULL;
-
-
- static void usage(void) {
- fprintf(stderr, "Usage: micrond <crondir>\n");
- }
-
-
- static inline uint64_t bit(unsigned b) {
- return ((uint64_t)1) << b;
- }
-
- static int strict_atoi(const char *s) {
- char *end;
- int ret = strtol(s, &end, 10);
-
- if (*end)
- return -1;
- else
- return ret;
- }
-
- static uint64_t parse_strings(const char *input, const char *const *strings, size_t n) {
- size_t i;
- for (i = 0; i < n; i++) {
- if (strcasecmp(input, strings[i]) == 0)
- return bit(i);
- }
-
- return 0;
- }
-
- static uint64_t parse_times(char *input, int min, int n) {
- uint64_t ret = 0;
- int step = 1;
-
- char *comma = strchr(input, ',');
- if (comma) {
- *comma = 0;
- ret = parse_times(comma+1, min, n);
-
- if (!ret)
- return 0;
- }
-
- char *slash = strchr(input, '/');
- if (slash) {
- *slash = 0;
- step = strict_atoi(slash+1);
-
- if (step <= 0)
- return 0;
- }
-
- int begin, end;
- char *minus = strchr(input, '-');
- if (minus) {
- *minus = 0;
- begin = strict_atoi(input);
- end = strict_atoi(minus+1);
- }
- else if (strcmp(input, "*") == 0) {
- begin = min;
- end = min+n-1;
- }
- else {
- begin = end = strict_atoi(input);
- }
-
- if (begin < min || end < min)
- return 0;
-
- int i;
- for (i = begin-min; i <= end-min; i += step)
- ret |= bit(i % n);
-
- return ret;
- }
-
- static int handle_line(const char *line) {
- job_t job = {};
- int ret = -1;
- char *columns[5];
- int i;
- int len;
-
- int matches = sscanf(line, "%ms %ms %ms %ms %ms %n", &columns[0], &columns[1], &columns[2], &columns[3], &columns[4], &len);
- if (matches != 5 && matches != 6) {
- if (matches <= 0)
- ret = 0;
-
- goto end;
- }
-
- job.minutes = parse_times(columns[0], 0, 60);
- if (!job.minutes)
- goto end;
-
- job.hours = parse_times(columns[1], 0, 24);
- if (!job.hours)
- goto end;
-
- job.doms = parse_times(columns[2], 1, 31);
- if (!job.doms)
- goto end;
-
-
- job.months = parse_strings(columns[3], MONTHS, 12);
-
- if (!job.months)
- job.months = parse_times(columns[3], 1, 12);
- if (!job.months)
- goto end;
-
- job.dows = parse_strings(columns[4], WEEKDAYS, 7);
- if (!job.dows)
- job.dows = parse_times(columns[4], 0, 7);
- if (!job.dows)
- goto end;
-
- job.command = strdup(line+len);
-
- job_t *jobp = malloc(sizeof(job_t));
- *jobp = job;
-
- jobp->next = jobs;
- jobs = jobp;
-
- ret = 0;
-
- end:
- for (i = 0; i < matches && i < 5; i++)
- free(columns[i]);
-
- return ret;
- }
-
-
- static void read_crontab(const char *name) {
- FILE *file = fopen(name, "r");
- if (!file) {
- syslog(LOG_WARNING, "unable to read crontab `%s'", name);
- return;
- }
-
- char line[16384];
- unsigned lineno = 0;
-
- while (fgets(line, sizeof(line), file)) {
- lineno++;
-
- char *comment = strchr(line, '#');
- if (comment)
- *comment = 0;
-
- if (handle_line(line))
- syslog(LOG_WARNING, "syntax error in `%s', line %u", name, lineno);
- }
-
- fclose(file);
- }
-
-
- static void read_crondir(void) {
- DIR *dir;
-
- if (chdir(crondir) || ((dir = opendir(".")) == NULL)) {
- fprintf(stderr, "Unable to read crondir `%s'\n", crondir);
- usage();
- exit(1);
- }
-
- struct dirent *ent;
- while ((ent = readdir(dir)) != NULL) {
- if (ent->d_name[0] == '.')
- continue;
-
- read_crontab(ent->d_name);
- }
-
- closedir(dir);
- }
-
-
- static void run_job(const job_t *job) {
- pid_t pid = fork();
- if (pid == 0) {
- execl("/bin/sh", "/bin/sh", "-c", job->command, (char*)NULL);
- syslog(LOG_ERR, "unable to run job: exec failed");
- _exit(1);
- }
- else if (pid < 0) {
- syslog(LOG_ERR, "unable to run job: fork failed");
- }
- }
-
-
- static void check_job(const job_t *job, const struct tm *tm) {
- if (!(job->minutes & bit(tm->tm_min)))
- return;
-
- if (!(job->hours & bit(tm->tm_hour)))
- return;
-
- if (!(job->doms & bit(tm->tm_mday-1)))
- return;
-
- if (!(job->months & bit(tm->tm_mon)))
- return;
-
- if (!(job->dows & bit(tm->tm_wday)))
- return;
-
- run_job(job);
- }
-
-
- int main(int argc, char *argv[]) {
- if (argc != 2) {
- usage();
-
- exit(argc < 2 ? 0 : 1);
- }
-
- crondir = argv[1];
-
- signal(SIGCHLD, SIG_IGN);
-
- read_crondir();
-
- time_t t = time(NULL);
- struct tm *tm = localtime(&t);
- int minute = tm->tm_min;
-
- while (1) {
- sleep(60 - t%60);
-
- t = time(NULL);
- tm = localtime(&t);
-
- minute = (minute+1)%60;
- if (tm->tm_min != minute) {
- /* clock has moved, don't execute jobs */
- minute = tm->tm_min;
- continue;
- }
-
- job_t *job;
- for (job = jobs; job; job = job->next)
- check_job(job, tm);
- }
- }
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