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-rw-r--r--toys/pending/crond.c681
1 files changed, 681 insertions, 0 deletions
diff --git a/toys/pending/crond.c b/toys/pending/crond.c
new file mode 100644
index 00000000..1b5e4194
--- /dev/null
+++ b/toys/pending/crond.c
@@ -0,0 +1,681 @@
+/* crond.c - daemon to execute scheduled commands.
+ *
+ * Copyright 2014 Ranjan Kumar <ranjankumar.bth@gmail.com>
+ *
+ * No Standard
+
+USE_CROND(NEWTOY(crond, "fbSl#<0=8d#<0L:c:[-bf][-LS][-ld]", TOYFLAG_USR|TOYFLAG_SBIN|TOYFLAG_NEEDROOT))
+
+config CROND
+ bool "crond"
+ default n
+ help
+ usage: crond [-fbS] [-l N] [-d N] [-L LOGFILE] [-c DIR]
+
+ A daemon to execute scheduled commands.
+
+ -b Background (default)
+ -c crontab dir
+ -d Set log level, log to stderr
+ -f Foreground
+ -l Set log level. 0 is the most verbose, default 8
+ -S Log to syslog (default)
+ -L Log to file
+*/
+
+#define FOR_crond
+#include "toys.h"
+
+GLOBALS(
+ char *crontabs_dir;
+ char *logfile;
+ int loglevel_d;
+ int loglevel;
+
+ time_t crontabs_dir_mtime;
+ uint8_t flagd;
+)
+
+typedef struct _var {
+ struct _var *next, *prev;
+ char *name, *val;
+} VAR;
+
+typedef struct _job {
+ struct _job *next, *prev;
+ char min[60], hour[24], dom[31], mon[12], dow[7], *cmd;
+ int isrunning, needstart, mailsize;
+ pid_t pid;
+} JOB;
+
+typedef struct _cronfile {
+ struct _cronfile *next, *prev;
+ struct double_list *job, *var;
+ char *username, *mailto;
+ int invalid;
+} CRONFILE;
+
+static char days[]={"sun""mon""tue""wed""thu""fri""sat"};
+static char months[]={"jan""feb""mar""apr""may""jun""jul"
+ "aug""sep""oct""nov""dec"};
+CRONFILE *gclist;
+
+#define LOG_EXIT 0
+#define LOG_LEVEL5 5
+#define LOG_LEVEL7 7
+#define LOG_LEVEL8 8
+#define LOG_LEVEL9 9 // warning
+#define LOG_ERROR 20
+
+static void loginfo(uint8_t loglevel, char *msg, ...)
+{
+ va_list s, d;
+
+ va_start(s, msg);
+ va_copy(d, s);
+ if (loglevel >= TT.loglevel) {
+ int used;
+ char *smsg;
+
+ if (!TT.flagd && TT.logfile) {
+ int fd = open(TT.logfile, O_WRONLY | O_CREAT | O_APPEND, 0666);
+ if (fd >=0 && fd != 2) {
+ dup2(fd, 2);
+ close(fd);
+ } else if (fd < 0) perror_msg("'%s", TT.logfile);
+ }
+ used = vsnprintf(NULL, 0, msg, d);
+ smsg = xzalloc(++used);
+ vsnprintf(smsg, used, msg, s);
+ if (TT.flagd || TT.logfile) {
+ fflush(NULL);
+ smsg[used-1] = '\n';
+ writeall((loglevel > 8) ? 2 : 1, smsg, used);
+ } else syslog((loglevel > 8) ? LOG_ERR : LOG_INFO, "%s", smsg);
+ free(smsg);
+ }
+ va_end(d);
+ va_end(s);
+ if (!loglevel) exit(20);
+}
+
+/*
+ * Names can also be used for the 'month' and 'day of week' fields
+ * (First three letters of the particular day or month).
+ */
+static int getindex(char *src, int size)
+{
+ int i;
+ char *field = (size == 12) ? months : days;
+
+ // strings are not allowed for min, hour and dom fields.
+ if (!(size == 7 || size == 12)) return -1;
+
+ for (i = 0; field[i]; i += 3) {
+ if (!strncasecmp(src, &field[i], 3))
+ return (i/3);
+ }
+ return -1;
+}
+
+// set elements of minute, hour, day of month, month and day of week arrays.
+static void fillarray(char *dst, int start, int end, int skip)
+{
+ int sk = 1;
+
+ if (end < 0) {
+ dst[start] = 1;
+ return;
+ }
+ if (!skip) skip = 1;
+ do {
+ if (!--sk) {
+ dst[start] = 1;
+ sk = skip;
+ }
+ } while (start++ != end);
+}
+
+static long getval(char *num, long low, long high)
+{
+ long val = strtol(num, &num, 10);
+
+ if (*num || (val < low) || (val > high)) return -1;
+ return val;
+}
+
+//static int parse_and_fillarray(char *dst, int size, char *src)
+static int parse_and_fillarray(char *dst, int min, int max, char *src)
+{
+ int start, end, skip = 0;
+ char *ptr = strchr(src, '/');
+
+ if (ptr) {
+ *ptr++ = 0;
+ if ((skip = getval(ptr, min, (min ? max: max-1))) < 0) goto ERROR;
+ }
+
+ if (*src == '-' || *src == ',') goto ERROR;
+ if (*src == '*') {
+ if (*(src+1)) goto ERROR;
+ fillarray(dst, 0, max-1, skip);
+ } else {
+ for (;;) {
+ char *ctoken = strsep(&src, ","), *dtoken;
+
+ if (!ctoken) break;
+ if (!*ctoken) goto ERROR;
+
+ // Get start position.
+ dtoken = strsep(&ctoken, "-");
+ if (isdigit(*dtoken)) {
+ if ((start = getval(dtoken, min, (min ? max : max-1))) < 0) goto ERROR;
+ start = min ? (start-1) : start;
+ } else if ((start = getindex(dtoken, max)) < 0) goto ERROR;
+
+ // Get end position.
+ if (!ctoken) end = -1; // e.g. N1,N2,N3
+ else if (*ctoken) {// e.g. N-M
+ if (isdigit(*ctoken)) {
+ if ((end = getval(ctoken, min, (min ? max : max-1))) < 0) goto ERROR;
+ end = min ? (end-1) : end;
+ } else if ((end = getindex(ctoken, max)) < 0) goto ERROR;
+ if (end == start) end = -1;
+ } else goto ERROR; // error condition 'N-'
+ fillarray(dst, start, end, skip);
+ }
+ }
+
+ if (TT.flagd && (TT.loglevel <= 5)) {
+ for (start = 0; start < max; start++)
+ fprintf(stderr, "%d", (unsigned char)dst[start]);
+ fputc('\n', stderr);
+ }
+ return 0;
+ERROR:
+ loginfo(LOG_LEVEL9, "parse error at %s", src);
+ return -1;
+}
+
+static char *omitspace(char *line)
+{
+ while (*line == ' ' || *line == '\t') line++;
+ return line;
+}
+
+static void parse_line(char *line, CRONFILE *cfile)
+{
+ int count = 0;
+ char *name, *val, *tokens[5] = {0,};
+ VAR *v;
+ JOB *j;
+
+ line = omitspace(line);
+ if (!*line || *line == '#') return;
+
+ /*
+ * TODO: Enhancement to support 8 special strings
+ * @reboot -> Run once at startup.
+ * @yearly -> Run once a year (0 0 1 1 *).
+ * @annually -> Same as above.
+ * @monthly -> Run once a month (0 0 1 * *).
+ * @weekly -> Run once a week (0 0 * * 0).
+ * @daily -> Run once a day (0 0 * * *).
+ * @midnight -> same as above.
+ * @hourly -> Run once an hour (0 * * * *).
+ */
+ if (*line == '@') return;
+ if (TT.flagd) loginfo(LOG_LEVEL5, "user:%s entry:%s", cfile->username, line);
+ while (count<5) {
+ int len = strcspn(line, " \t");
+
+ if (line[len]) line[len++] = '\0';
+ tokens[count++] = line;
+ line += len;
+ line = omitspace(line);
+ if (!*line) break;
+ }
+
+ switch (count) {
+ case 1: // form SHELL=/bin/sh
+ name = tokens[0];
+ if ((val = strchr(name, '='))) *val++ = 0;
+ if (!val || !*val) return;
+ break;
+ case 2: // form SHELL =/bin/sh or SHELL= /bin/sh
+ name = tokens[0];
+ if ((val = strchr(name, '='))) {
+ *val = 0;
+ val = tokens[1];
+ } else {
+ if (*(tokens[1]) != '=') return;
+ val = tokens[1] + 1;
+ }
+ if (!*val) return;
+ break;
+ case 3: // NAME = VAL
+ name = tokens[0];
+ val = tokens[2];
+ if (*(tokens[1]) != '=') return;
+ break;
+ case 5:
+ // don't have any cmd to execute.
+ if (!*line) return;
+ j = xzalloc(sizeof(JOB));
+
+ if (parse_and_fillarray(j->min, 0, sizeof(j->min), tokens[0]))
+ goto STOP_PARSING;
+ if (parse_and_fillarray(j->hour, 0, sizeof(j->hour), tokens[1]))
+ goto STOP_PARSING;
+ if (parse_and_fillarray(j->dom, 1, sizeof(j->dom), tokens[2]))
+ goto STOP_PARSING;
+ if (parse_and_fillarray(j->mon, 1, sizeof(j->mon), tokens[3]))
+ goto STOP_PARSING;
+ if (parse_and_fillarray(j->dow, 0, sizeof(j->dow), tokens[4]))
+ goto STOP_PARSING;
+ j->cmd = xstrdup(line);
+
+ if (TT.flagd) loginfo(LOG_LEVEL5, " command:%s", j->cmd);
+ dlist_add_nomalloc((struct double_list **)&cfile->job, (struct double_list *)j);
+ return;
+STOP_PARSING:
+ free(j);
+ return;
+ default: return;
+ }
+ if (!strcmp(name, "MAILTO")) cfile->mailto = xstrdup(val);
+ else {
+ v = xzalloc(sizeof(VAR));
+ v->name = xstrdup(name);
+ v->val = xstrdup(val);
+ dlist_add_nomalloc((struct double_list **)&cfile->var, (struct double_list *)v);
+ }
+}
+
+static void free_jobs(JOB **jlist)
+{
+ JOB *j = dlist_pop(jlist);
+ free(j->cmd);
+ free(j);
+}
+
+static void free_cronfile(CRONFILE **list)
+{
+ CRONFILE *l = dlist_pop(list);
+ VAR *v, *vnode = (VAR *)l->var;
+
+ if (l->username != l->mailto) free(l->mailto);
+ free(l->username);
+ while (vnode && (v = dlist_pop(&vnode))) {
+ free(v->name);
+ free(v->val);
+ free(v);
+ }
+ free(l);
+}
+
+/*
+ * Iterate all cronfiles to identify the completed jobs and freed them.
+ * If all jobs got completed for a cronfile, freed cronfile too.
+ */
+static void remove_completed_jobs()
+{
+ CRONFILE *lstart, *list = gclist;
+
+ lstart = list;
+ while (list) {
+ int delete = 1;
+ JOB *jstart, *jlist = (JOB *)list->job;
+
+ list->invalid = 1;
+ jstart = jlist;
+ while (jlist) {
+ jlist->isrunning = 0;
+ if (jlist->pid > 0) {
+ jlist->isrunning = 1;
+ delete = 0;
+ jlist = jlist->next;
+ } else {
+ if (jlist == jstart) { // if 1st node has to delete.
+ jstart = jstart->next;
+ free_jobs(&jlist);
+ continue;
+ } else free_jobs(&jlist);
+ }
+ if (jlist == jstart) break;
+ }
+ list->job = (struct double_list *)jlist;
+
+ if (delete) {
+ if (lstart == list) {
+ lstart = lstart->next;
+ free_cronfile(&list);
+ continue;
+ } else free_cronfile(&list);
+ }
+ list = list->next;
+ if (lstart == list) break;
+ }
+ gclist = list;
+}
+
+// Scan cronfiles and prepare the list of cronfiles with their jobs.
+static void scan_cronfiles()
+{
+ DIR *dp;
+ struct dirent *entry;
+
+ remove_completed_jobs();
+ if (chdir(TT.crontabs_dir)) loginfo(LOG_EXIT, "chdir(%s)", TT.crontabs_dir);
+ if (!(dp = opendir("."))) loginfo(LOG_EXIT, "chdir(%s)", ".");
+
+ while ((entry = readdir(dp))) {
+ int fd;
+ char *line;
+ CRONFILE *cfile;
+
+ if (entry->d_name[0] == '.' && (!entry->d_name[1] ||
+ (entry->d_name[1] == '.' && !entry->d_name[2])))
+ continue;
+
+ if (!getpwnam(entry->d_name)) {
+ loginfo(LOG_LEVEL7, "ignoring file '%s' (no such user)", entry->d_name);
+ continue;
+ }
+ if ((fd = open(entry->d_name, O_RDONLY)) < 0) continue;
+
+ // one node for each user
+ cfile = xzalloc(sizeof(CRONFILE));
+ cfile->username = xstrdup(entry->d_name);
+
+ for (; (line = get_line(fd)); free(line))
+ parse_line(line, cfile);
+
+ // If there is no job for a cron, remove the VAR list.
+ if (!cfile->job) {
+ VAR *v, *vnode = (VAR *)cfile->var;
+
+ free(cfile->username);
+ if (cfile->mailto) free(cfile->mailto);
+
+ while (vnode && (v = dlist_pop(&vnode))) {
+ free(v->name);
+ free(v->val);
+ free(v);
+ }
+ free(cfile);
+ } else {
+ if (!cfile->mailto) cfile->mailto = cfile->username;
+ dlist_add_nomalloc((struct double_list **)&gclist,
+ (struct double_list *)cfile);
+ }
+ close(fd);
+ }
+ closedir(dp);
+}
+
+/*
+ * Set env variables, if any in the cronfile. Execute given job with the given
+ * SHELL or Default SHELL and send an e-mail with respect to every successfully
+ * completed job (as per the given param 'prog').
+ */
+static void do_fork(CRONFILE *cfile, JOB *job, int fd, char *prog)
+{
+ pid_t pid = vfork();
+
+ if (pid == 0) {
+ VAR *v, *vstart = (VAR *)cfile->var;
+ struct passwd *pwd = getpwnam(cfile->username);
+
+ if (!pwd) loginfo(LOG_LEVEL9, "can't get uid for %s", cfile->username);
+ else {
+ char *file = "/bin/sh";
+
+ if (setenv("USER", pwd->pw_name, 1)) _exit(1);
+ for (v = vstart; v;) {
+ if (!strcmp("SHELL", v->name)) file = v->val;
+ if (setenv(v->name, v->val, 1)) _exit(1);
+ if ((v=v->next) == vstart) break;
+ }
+ if (!getenv("HOME")) {
+ if (setenv("HOME", pwd->pw_dir, 1))
+ _exit(1);
+ }
+ xsetuser(pwd);
+ if (chdir(pwd->pw_dir)) loginfo(LOG_LEVEL9, "chdir(%s)", pwd->pw_dir);
+ if (prog) file = prog;
+ if (TT.flagd) loginfo(LOG_LEVEL5, "child running %s", file);
+
+ if (fd >= 0) {
+ int newfd = prog ? 0 : 1;
+ if (fd != newfd) {
+ dup2(fd, newfd);
+ close(fd);
+ }
+ dup2(1, 2);
+ }
+ setpgrp();
+ execlp(file, file, (prog ? "-ti" : "-c"), (prog ? NULL : job->cmd), (char *) NULL);
+ loginfo(LOG_ERROR, "can't execute '%s' for user %s", file, cfile->username);
+
+ if (!prog) dprintf(1, "Exec failed: %s -c %s\n", file, job->cmd);
+ _exit(EXIT_SUCCESS);
+ }
+ }
+ if (pid < 0) {
+ loginfo(LOG_ERROR, "can't vfork");
+ pid = 0;
+ }
+ if (fd >=0) close(fd);
+ job->pid = pid;
+}
+
+// Send an e-mail for each successfully completed jobs.
+static void sendmail(CRONFILE *cfile, JOB *job)
+{
+ pid_t pid = job->pid;
+ int mailfd;
+ struct stat sb;
+
+ job->pid = 0;
+ if (pid <=0 || job->mailsize <=0) {
+ job->isrunning = 0;
+ job->needstart = 1;
+ return;
+ }
+ snprintf(toybuf, sizeof(toybuf), "/var/spool/cron/cron.%s.%d",
+ cfile->username, (int)pid);
+
+ mailfd = open(toybuf, O_RDONLY);
+ unlink(toybuf);
+ if (mailfd < 0) return;
+
+ if (fstat(mailfd, &sb) == -1 || sb.st_uid != 0 || sb.st_nlink != 0
+ || sb.st_size == job->mailsize || !S_ISREG(sb.st_mode)) {
+ xclose(mailfd);
+ return;
+ }
+ job->mailsize = 0;
+ do_fork(cfile, job, mailfd, "sendmail");
+}
+
+// Count the number of jobs, which are not completed.
+static int count_running_jobs()
+{
+ CRONFILE *cfile = gclist;
+ JOB *job, *jstart;
+ int count = 0;
+
+ while (cfile) {
+ job = jstart = (JOB *)cfile->job;
+ while (job) {
+ int ret;
+
+ if (!job->isrunning || job->pid<=0) goto NEXT_JOB;
+ job->isrunning = 0;
+ ret = waitpid(job->pid, NULL, WNOHANG);
+ if (ret < 0 || ret == job->pid) {
+ sendmail(cfile, job);
+ if (job->pid) count += (job->isrunning=1);
+ else {
+ job->isrunning = 0;
+ job->needstart = 1;
+ }
+ }
+ else count += (job->isrunning=1);
+
+NEXT_JOB:
+ if ((job = job->next) == jstart) break;
+ }
+ if ((cfile = cfile->next) == gclist) break;
+ }
+ return count;
+}
+
+// Execute jobs one by one and prepare for the e-mail sending.
+static void execute_jobs(void)
+{
+ CRONFILE *cfile = gclist;
+ JOB *job, *jstart;
+
+ while (cfile) {
+ job = jstart = (JOB *)cfile->job;
+ while (job) {
+ if (job->needstart) {
+ job->needstart = 0;
+ if (job->pid < 0) {
+ int mailfd = -1;
+
+ job->mailsize = job->pid = 0;
+ snprintf(toybuf, sizeof(toybuf), "/var/spool/cron/cron.%s.%d",
+ cfile->username, getpid());
+ if ((mailfd = open(toybuf, O_CREAT|O_TRUNC|O_WRONLY|O_EXCL|O_APPEND,
+ 0600)) < 0) {
+ loginfo(LOG_ERROR, "can't create mail file %s for user %s, "
+ "discarding output", toybuf, cfile->username);
+ } else {
+ dprintf(mailfd, "To: %s\nSubject: cron: %s\n\n", cfile->mailto, job->cmd);
+ job->mailsize = lseek(mailfd, 0, SEEK_CUR);
+ }
+ do_fork(cfile, job, mailfd, NULL);
+ if (mailfd >= 0) {
+ if (job->pid <= 0) unlink(toybuf);
+ else {
+ char *mailfile = xmprintf("/var/spool/cron/cron.%s.%d",
+ cfile->username, (int)job->pid);
+ rename(toybuf, mailfile);
+ free(mailfile);
+ }
+ }
+ loginfo(LOG_LEVEL8, "USER %s pid %3d cmd %s",
+ cfile->username, job->pid, job->cmd);
+ if (job->pid < 0) job->needstart = 1;
+ else job->isrunning = 1;
+ }
+ }
+ if ((job = job->next) == jstart) break;
+ }
+ if ((cfile = cfile->next) == gclist) break;
+ }
+}
+
+// Identify jobs, which needs to be started at the given time interval.
+static void schedule_jobs(time_t ctime, time_t ptime)
+{
+ time_t tm = ptime-ptime%60;
+
+ for (; tm <= ctime; tm += 60) {
+ struct tm *lt;
+ CRONFILE *cfile = gclist;
+ JOB *job, *jstart;
+
+ if (tm <= ptime) continue;
+ lt = localtime(&tm);
+
+ while (cfile) {
+ if (TT.flagd) loginfo(LOG_LEVEL5, "file %s:", cfile->username);
+ if (cfile->invalid) goto NEXT_CRONFILE;
+ job = jstart = (JOB *)cfile->job;
+
+ while (job) {
+ if (TT.flagd) loginfo(LOG_LEVEL5, " line %s", job->cmd);
+
+ if (job->min[lt->tm_min] && job->hour[lt->tm_hour]
+ && (job->dom[lt->tm_mday] || job->dow[lt->tm_wday])
+ && job->mon[lt->tm_mon-1]) {
+ if (TT.flagd)
+ loginfo(LOG_LEVEL5, " job: %d %s\n", (int)job->pid, job->cmd);
+ if (job->pid > 0) {
+ loginfo(LOG_LEVEL8, "user %s: process already running: %s",
+ cfile->username, job->cmd);
+ } else if (!job->pid) {
+ job->pid = -1;
+ job->needstart = 1;
+ job->isrunning = 0;
+ }
+ }
+ if ((job = job->next) == jstart) break;
+ }
+NEXT_CRONFILE:
+ if ((cfile = cfile->next) == gclist) break;
+ }
+ }
+}
+
+void crond_main(void)
+{
+ time_t ctime, ptime;
+ int sleepfor = 60;
+ struct stat sb;
+
+ TT.flagd = (toys.optflags & FLAG_d);
+
+ // Setting default params.
+ if (TT.flagd) TT.loglevel = TT.loglevel_d;
+ if (!(toys.optflags & (FLAG_f | FLAG_b))) toys.optflags |= FLAG_b;
+ if (!(toys.optflags & (FLAG_S | FLAG_L))) toys.optflags |= FLAG_S;
+
+ if ((toys.optflags & FLAG_c)
+ && (TT.crontabs_dir[strlen(TT.crontabs_dir)-1] != '/'))
+ TT.crontabs_dir = xmprintf("%s/", TT.crontabs_dir);
+
+ if (!TT.crontabs_dir) TT.crontabs_dir = xstrdup("/var/spool/cron/crontabs/");
+ if (toys.optflags & FLAG_b) daemon(0,0);
+
+ if (!TT.flagd && !TT.logfile)
+ openlog(toys.which->name, LOG_CONS | LOG_PID, LOG_CRON);
+
+ // Set default shell once.
+ if (setenv("SHELL", "/bin/sh", 1)) error_exit("Can't set default shell");
+ xchdir(TT.crontabs_dir);
+ loginfo(LOG_LEVEL8, "crond started, log level %d", TT.loglevel);
+
+ if (stat(TT.crontabs_dir, &sb)) sb.st_mtime = 0;
+ TT.crontabs_dir_mtime = sb.st_mtime;
+ scan_cronfiles();
+ ctime = time(NULL);
+
+ while (1) {
+ long tdiff;
+
+ ptime = ctime;
+ sleep(sleepfor - (ptime%sleepfor) +1);
+ tdiff =(long) ((ctime = time(NULL)) - ptime);
+
+ if (stat(TT.crontabs_dir, &sb)) sb.st_mtime = 0;
+ if (TT.crontabs_dir_mtime != sb.st_mtime) {
+ TT.crontabs_dir_mtime = sb.st_mtime;
+ scan_cronfiles();
+ }
+
+ if (TT.flagd) loginfo(LOG_LEVEL5, "wakeup diff=%ld\n", tdiff);
+ if (tdiff < -60 * 60 || tdiff > 60 * 60)
+ loginfo(LOG_LEVEL9, "time disparity of %ld minutes detected", tdiff / 60);
+ else if (tdiff > 0) {
+ schedule_jobs(ctime, ptime);
+ execute_jobs();
+ if (count_running_jobs()) sleepfor = 10;
+ else sleepfor = 60;
+ }
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-11 09:51:28 +0000