| /* See LICENSE file for copyright and license details. */ |
| #include <sys/wait.h> |
| |
| #include <errno.h> |
| #include <signal.h> |
| #include <stdarg.h> |
| #include <stdlib.h> |
| #include <stdio.h> |
| #include <string.h> |
| #include <syslog.h> |
| #include <time.h> |
| #include <unistd.h> |
| |
| #include "queue.h" |
| #include "util.h" |
| |
| struct field { |
| /* [low, high] */ |
| long low; |
| long high; |
| /* for every `div' units */ |
| long div; |
| }; |
| |
| struct ctabentry { |
| struct field min; |
| struct field hour; |
| struct field mday; |
| struct field mon; |
| struct field wday; |
| char *cmd; |
| TAILQ_ENTRY(ctabentry) entry; |
| }; |
| |
| struct jobentry { |
| char *cmd; |
| pid_t pid; |
| TAILQ_ENTRY(jobentry) entry; |
| }; |
| |
| static sig_atomic_t chldreap; |
| static sig_atomic_t reload; |
| static sig_atomic_t quit; |
| static TAILQ_HEAD(, ctabentry) ctabhead = TAILQ_HEAD_INITIALIZER(ctabhead); |
| static TAILQ_HEAD(, jobentry) jobhead = TAILQ_HEAD_INITIALIZER(jobhead); |
| static char *config = "/etc/crontab"; |
| static char *pidfile = "/var/run/crond.pid"; |
| static int nflag; |
| |
| static void |
| loginfo(const char *fmt, ...) |
| { |
| va_list ap; |
| va_start(ap, fmt); |
| if (nflag == 0) |
| vsyslog(LOG_INFO, fmt, ap); |
| else |
| vfprintf(stdout, fmt, ap); |
| fflush(stdout); |
| va_end(ap); |
| } |
| |
| static void |
| logwarn(const char *fmt, ...) |
| { |
| va_list ap; |
| va_start(ap, fmt); |
| if (nflag == 0) |
| vsyslog(LOG_WARNING, fmt, ap); |
| else |
| vfprintf(stderr, fmt, ap); |
| va_end(ap); |
| } |
| |
| static void |
| logerr(const char *fmt, ...) |
| { |
| va_list ap; |
| va_start(ap, fmt); |
| if (nflag == 0) |
| vsyslog(LOG_ERR, fmt, ap); |
| else |
| vfprintf(stderr, fmt, ap); |
| va_end(ap); |
| } |
| |
| static void |
| runjob(char *cmd) |
| { |
| struct jobentry *je; |
| time_t t; |
| pid_t pid; |
| |
| t = time(NULL); |
| |
| /* If command is already running, skip it */ |
| TAILQ_FOREACH(je, &jobhead, entry) { |
| if (strcmp(je->cmd, cmd) == 0) { |
| loginfo("already running %s pid: %d at %s", |
| je->cmd, je->pid, ctime(&t)); |
| return; |
| } |
| } |
| |
| switch ((pid = fork())) { |
| case -1: |
| logerr("error: failed to fork job: %s time: %s", |
| cmd, ctime(&t)); |
| return; |
| case 0: |
| setsid(); |
| loginfo("run: %s pid: %d at %s", |
| cmd, getpid(), ctime(&t)); |
| execl("/bin/sh", "/bin/sh", "-c", cmd, (char *)NULL); |
| logwarn("error: failed to execute job: %s time: %s", |
| cmd, ctime(&t)); |
| _exit(1); |
| default: |
| je = emalloc(sizeof(*je)); |
| je->cmd = estrdup(cmd); |
| je->pid = pid; |
| TAILQ_INSERT_TAIL(&jobhead, je, entry); |
| } |
| } |
| |
| static void |
| waitjob(void) |
| { |
| struct jobentry *je, *tmp; |
| int status; |
| time_t t; |
| pid_t pid; |
| |
| t = time(NULL); |
| |
| while ((pid = waitpid(-1, &status, WNOHANG | WUNTRACED)) > 0) { |
| je = NULL; |
| TAILQ_FOREACH(tmp, &jobhead, entry) { |
| if (tmp->pid == pid) { |
| je = tmp; |
| break; |
| } |
| } |
| if (je) { |
| TAILQ_REMOVE(&jobhead, je, entry); |
| free(je->cmd); |
| free(je); |
| } |
| if (WIFEXITED(status) == 1) |
| loginfo("complete: pid: %d returned: %d time: %s", |
| pid, WEXITSTATUS(status), ctime(&t)); |
| else if (WIFSIGNALED(status) == 1) |
| loginfo("complete: pid: %d terminated by signal: %s time: %s", |
| pid, strsignal(WTERMSIG(status)), ctime(&t)); |
| else if (WIFSTOPPED(status) == 1) |
| loginfo("complete: pid: %d stopped by signal: %s time: %s", |
| pid, strsignal(WSTOPSIG(status)), ctime(&t)); |
| } |
| } |
| |
| static int |
| isleap(int year) |
| { |
| if (year % 400 == 0) |
| return 1; |
| if (year % 100 == 0) |
| return 0; |
| return (year % 4 == 0); |
| } |
| |
| static int |
| daysinmon(int mon, int year) |
| { |
| int days[12] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; |
| if (year < 1900) |
| year += 1900; |
| if (isleap(year)) |
| days[1] = 29; |
| return days[mon]; |
| } |
| |
| static int |
| matchentry(struct ctabentry *cte, struct tm *tm) |
| { |
| struct { |
| struct field *f; |
| int tm; |
| int len; |
| } matchtbl[] = { |
| { .f = &cte->min, .tm = tm->tm_min, .len = 60 }, |
| { .f = &cte->hour, .tm = tm->tm_hour, .len = 24 }, |
| { .f = &cte->mday, .tm = tm->tm_mday, .len = daysinmon(tm->tm_mon, tm->tm_year) }, |
| { .f = &cte->mon, .tm = tm->tm_mon, .len = 12 }, |
| { .f = &cte->wday, .tm = tm->tm_wday, .len = 7 }, |
| }; |
| size_t i; |
| |
| for (i = 0; i < LEN(matchtbl); i++) { |
| if (matchtbl[i].f->high == -1) { |
| if (matchtbl[i].f->low == -1) { |
| continue; |
| } else if (matchtbl[i].f->div > 0) { |
| if (matchtbl[i].tm > 0) { |
| if (matchtbl[i].tm % matchtbl[i].f->div == 0) |
| continue; |
| } else { |
| if (matchtbl[i].len % matchtbl[i].f->div == 0) |
| continue; |
| } |
| } else if (matchtbl[i].f->low == matchtbl[i].tm) { |
| continue; |
| } |
| } else if (matchtbl[i].f->low <= matchtbl[i].tm && |
| matchtbl[i].f->high >= matchtbl[i].tm) { |
| continue; |
| } |
| break; |
| } |
| if (i != LEN(matchtbl)) |
| return 0; |
| return 1; |
| } |
| |
| static int |
| parsefield(const char *field, long low, long high, struct field *f) |
| { |
| long min, max, div; |
| char *e1, *e2; |
| |
| if (strcmp(field, "*") == 0) { |
| f->low = -1; |
| f->high = -1; |
| return 0; |
| } |
| |
| div = -1; |
| max = -1; |
| min = strtol(field, &e1, 10); |
| |
| switch (e1[0]) { |
| case '-': |
| e1++; |
| errno = 0; |
| max = strtol(e1, &e2, 10); |
| if (e2[0] != '\0' || errno != 0) |
| return -1; |
| break; |
| case '*': |
| e1++; |
| if (e1[0] != '/') |
| return -1; |
| e1++; |
| errno = 0; |
| div = strtol(e1, &e2, 10); |
| if (e2[0] != '\0' || errno != 0) |
| return -1; |
| break; |
| case '\0': |
| break; |
| default: |
| return -1; |
| } |
| |
| if (min < low || min > high) |
| return -1; |
| if (max != -1) |
| if (max < low || max > high) |
| return -1; |
| if (div != -1) |
| if (div < low || div > high) |
| return -1; |
| |
| f->low = min; |
| f->high = max; |
| f->div = div; |
| return 0; |
| } |
| |
| static void |
| unloadentries(void) |
| { |
| struct ctabentry *cte, *tmp; |
| |
| for (cte = TAILQ_FIRST(&ctabhead); cte; cte = tmp) { |
| tmp = TAILQ_NEXT(cte, entry); |
| TAILQ_REMOVE(&ctabhead, cte, entry); |
| free(cte->cmd); |
| free(cte); |
| } |
| } |
| |
| static int |
| loadentries(void) |
| { |
| struct ctabentry *cte; |
| FILE *fp; |
| char *line = NULL, *p, *col; |
| int r = 0, y; |
| size_t size = 0; |
| ssize_t len; |
| |
| if ((fp = fopen(config, "r")) == NULL) { |
| logerr("error: can't open %s: %s\n", config, strerror(errno)); |
| return -1; |
| } |
| |
| for (y = 0; (len = getline(&line, &size, fp)) > 0; y++) { |
| p = line; |
| if (line[0] == '#' || line[0] == '\n' || line[0] == '\0') |
| continue; |
| |
| cte = emalloc(sizeof(*cte)); |
| |
| col = strsep(&p, "\t"); |
| if (!col || parsefield(col, 0, 59, &cte->min) < 0) { |
| logerr("error: failed to parse `min' field on line %d\n", |
| y + 1); |
| free(cte); |
| r = -1; |
| break; |
| } |
| |
| col = strsep(&p, "\t"); |
| if (!col || parsefield(col, 0, 23, &cte->hour) < 0) { |
| logerr("error: failed to parse `hour' field on line %d\n", |
| y + 1); |
| free(cte); |
| r = -1; |
| break; |
| } |
| |
| col = strsep(&p, "\t"); |
| if (!col || parsefield(col, 1, 31, &cte->mday) < 0) { |
| logerr("error: failed to parse `mday' field on line %d\n", |
| y + 1); |
| free(cte); |
| r = -1; |
| break; |
| } |
| |
| col = strsep(&p, "\t"); |
| if (!col || parsefield(col, 1, 12, &cte->mon) < 0) { |
| logerr("error: failed to parse `mon' field on line %d\n", |
| y + 1); |
| free(cte); |
| r = -1; |
| break; |
| } |
| |
| col = strsep(&p, "\t"); |
| if (!col || parsefield(col, 0, 6, &cte->wday) < 0) { |
| logerr("error: failed to parse `wday' field on line %d\n", |
| y + 1); |
| free(cte); |
| r = -1; |
| break; |
| } |
| |
| col = strsep(&p, "\n"); |
| if (!col) { |
| logerr("error: missing `cmd' field on line %d\n", |
| y + 1); |
| free(cte); |
| r = -1; |
| break; |
| } |
| cte->cmd = estrdup(col); |
| |
| TAILQ_INSERT_TAIL(&ctabhead, cte, entry); |
| } |
| |
| if (r < 0) |
| unloadentries(); |
| |
| free(line); |
| fclose(fp); |
| |
| return r; |
| } |
| |
| static void |
| reloadentries(void) |
| { |
| unloadentries(); |
| if (loadentries() < 0) |
| logwarn("warning: discarding old crontab entries\n"); |
| } |
| |
| static void |
| sighandler(int sig) |
| { |
| switch (sig) { |
| case SIGCHLD: |
| chldreap = 1; |
| break; |
| case SIGHUP: |
| reload = 1; |
| break; |
| case SIGTERM: |
| quit = 1; |
| break; |
| } |
| } |
| |
| static void |
| usage(void) |
| { |
| eprintf("usage: %s [-f file] [-n]\n", argv0); |
| } |
| |
| int |
| main(int argc, char *argv[]) |
| { |
| FILE *fp; |
| struct ctabentry *cte; |
| time_t t; |
| struct tm *tm; |
| struct sigaction sa; |
| |
| ARGBEGIN { |
| case 'n': |
| nflag = 1; |
| break; |
| case 'f': |
| config = EARGF(usage()); |
| break; |
| default: |
| usage(); |
| } ARGEND |
| |
| if (argc > 0) |
| usage(); |
| |
| if (nflag == 0) { |
| openlog(argv[0], LOG_CONS | LOG_PID, LOG_CRON); |
| if (daemon(1, 0) < 0) { |
| logerr("error: failed to daemonize %s\n", strerror(errno)); |
| return 1; |
| } |
| if ((fp = fopen(pidfile, "w"))) { |
| fprintf(fp, "%d\n", getpid()); |
| fclose(fp); |
| } |
| } |
| |
| sa.sa_handler = sighandler; |
| sigfillset(&sa.sa_mask); |
| sa.sa_flags = SA_RESTART; |
| sigaction(SIGCHLD, &sa, NULL); |
| sigaction(SIGHUP, &sa, NULL); |
| sigaction(SIGTERM, &sa, NULL); |
| |
| loadentries(); |
| |
| while (1) { |
| t = time(NULL); |
| sleep(60 - t % 60); |
| |
| if (quit == 1) { |
| if (nflag == 0) |
| unlink(pidfile); |
| unloadentries(); |
| /* Don't wait or kill forked processes, just exit */ |
| break; |
| } |
| |
| if (reload == 1 || chldreap == 1) { |
| if (reload == 1) { |
| reloadentries(); |
| reload = 0; |
| } |
| if (chldreap == 1) { |
| waitjob(); |
| chldreap = 0; |
| } |
| continue; |
| } |
| |
| TAILQ_FOREACH(cte, &ctabhead, entry) { |
| t = time(NULL); |
| tm = localtime(&t); |
| if (matchentry(cte, tm) == 1) |
| runjob(cte->cmd); |
| } |
| } |
| |
| if (nflag == 0) |
| closelog(); |
| |
| return 0; |
| } |