xref: /illumos-gate/usr/src/cmd/cron/cron.c (revision bbf21555)

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright 2013 Joshua M. Clulow <josh@sysmgr.org>
 *
 * Copyright (c) 2014 Gary Mills
 * Copyright (c) 2016 by Delphix. All rights reserved.
 * Copyright 2019 OmniOS Community Edition (OmniOSce) Association.
 * Copyright 2022 Sebastian Wiedenroth
 */

/*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
/*	  All Rights Reserved	*/

/*	Copyright (c) 1987, 1988 Microsoft Corporation	*/
/*	  All Rights Reserved	*/

#include <sys/contract/process.h>
#include <sys/ctfs.h>
#include <sys/param.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/task.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/utsname.h>
#include <sys/wait.h>

#include <security/pam_appl.h>

#include <alloca.h>
#include <ctype.h>
#include <deflt.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <grp.h>
#include <libcontract.h>
#include <libcontract_priv.h>
#include <limits.h>
#include <locale.h>
#include <poll.h>
#include <project.h>
#include <pwd.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stropts.h>
#include <time.h>
#include <unistd.h>
#include <libzoneinfo.h>

#include "cron.h"

/*
 * #define	DEBUG
 */

#define	MAIL		"/usr/bin/mail"	/* mail program to use */
#define	CONSOLE		"/dev/console"	/* where messages go when cron dies */

#define	TMPINFILE	"/tmp/crinXXXXXX"  /* file to put stdin in for cmd  */
#define	TMPDIR		"/tmp"
#define	PFX		"crout"
#define	TMPOUTFILE	"/tmp/croutXXXXXX" /* file to place stdout, stderr */

#define	INMODE		00400		/* mode for stdin file	*/
#define	OUTMODE		00600		/* mode for stdout file */
#define	ISUID		S_ISUID		/* mode for verifing at jobs */

#define	INFINITY	2147483647L	/* upper bound on time	*/
#define	CUSHION		180L
#define	ZOMB		100		/* proc slot used for mailing output */

#define	JOBF		'j'
#define	NICEF		'n'
#define	USERF		'u'
#define	WAITF		'w'

#define	BCHAR		'>'
#define	ECHAR		'<'

#define	DEFAULT		0
#define	LOAD		1
#define	QBUFSIZ		80

/* Defined actions for crabort() routine */
#define	NO_ACTION	000
#define	REMOVE_FIFO	001
#define	CONSOLE_MSG	002

#define	BADCD		"can't change directory to the crontab directory."
#define	NOREADDIR	"can't read the crontab directory."

#define	BADJOBOPEN	"unable to read your at job."
#define	BADSHELL	"because your login shell \
isn't /usr/bin/sh, you can't use cron."

#define	BADSTAT		"can't access your crontab or at-job file. Resubmit it."
#define	BADPROJID	"can't set project id for your job."
#define	CANTCDHOME	"can't change directory to %s.\
\nYour commands will not be executed."
#define	CANTEXECSH	"unable to exec the shell, %s, for one of your \
commands."
#define	CANT_STR_LEN (sizeof (CANTEXECSH) > sizeof (CANTCDHOME) ? \
	sizeof (CANTEXECSH) : sizeof (CANTCDHOME))
#define	NOREAD		"can't read your crontab file.  Resubmit it."
#define	BADTYPE		"crontab or at-job file is not a regular file.\n"
#define	NOSTDIN		"unable to create a standard input file for \
one of your crontab commands. \
\nThat command was not executed."

#define	NOTALLOWED	"you are not authorized to use cron.  Sorry."
#define	STDERRMSG	"\n\n********************************************\
*****\nCron: The previous message is the \
standard output and standard error \
\nof one of your cron commands.\n"

#define	STDOUTERR	"one of your commands generated output or errors, \
but cron was unable to mail you this output.\
\nRemember to redirect standard output and standard \
error for each of your commands."

#define	CLOCK_DRIFT	"clock time drifted backwards after event!\n"
#define	PIDERR		"unexpected pid returned %d (ignored)"
#define	CRONTABERR	"Subject: Your crontab file has an error in it\n\n"
#define	MALLOCERR	"out of space, cannot create new string\n"

#define	DIDFORK didfork
#define	NOFORK !didfork

#define	MAILBUFLEN	(8*1024)
#define	LINELIMIT	80
#define	MAILBINITFREE	(MAILBUFLEN - (sizeof (cte_intro) - 1) \
	    - (sizeof (cte_trail1) - 1) - (sizeof (cte_trail2) - 1) - 1)

#define	ERR_CRONTABENT	0	/* error in crontab file entry */
#define	ERR_UNIXERR	1	/* error in some system call */
#define	ERR_CANTEXECCRON 2	/* error setting up "cron" job environment */
#define	ERR_CANTEXECAT	3	/* error setting up "at" job environment */
#define	ERR_NOTREG	4	/* error not a regular file */

#define	PROJECT		"project="

#define	MAX_LOST_CONTRACTS	2048	/* reset if this many failed abandons */

#define	FORMAT	"%a %b %e %H:%M:%S %Y"
static char	timebuf[80];

static struct message msgbuf;

struct shared {
	int count;			/* usage count */
	void (*free)(void *obj);	/* routine that will free obj */
	void *obj;			/* object */
};

struct event {
	time_t time;	/* time of the event	*/
	short etype;	/* what type of event; 0=cron, 1=at	*/
	char *cmd;	/* command for cron, job name for at	*/
	struct usr *u;	/* ptr to the owner (usr) of this event	*/
	struct event *link;	/* ptr to another event for this user */
	union {
		struct { /* for crontab events */
			char *minute;	/*  (these	*/
			char *hour;	/*   fields	*/
			char *daymon;	/*   are	*/
			char *month;	/*   from	*/
			char *dayweek;	/*   crontab)	*/
			char *input;	/* ptr to stdin	*/
			struct shared *tz;	/* timezone of this event */
			struct shared *home;	/* directory for this event */
			struct shared *shell;	/* shell for this event */
			uint32_t max_random_delay;	/* max. random delay */
		} ct;
		struct { /* for at events */
			short exists;	/* for revising at events	*/
			int eventid;	/* for el_remove-ing at events	*/
		} at;
	} of;
};

struct usr {
	char *name;	/* name of user (e.g. "root")	*/
	char *home;	/* home directory for user	*/
	uid_t uid;	/* user id	*/
	gid_t gid;	/* group id	*/
	int aruncnt;	/* counter for running jobs per uid */
	int cruncnt;	/* counter for running cron jobs per uid */
	int ctid;	/* for el_remove-ing crontab events */
	short ctexists;	/* for revising crontab events	*/
	struct event *ctevents;	/* list of this usr's crontab events */
	struct event *atevents;	/* list of this usr's at events */
	struct usr *nextusr;
};	/* ptr to next user	*/

static struct	queue
{
	int njob;	/* limit */
	int nice;	/* nice for execution */
	int nwait;	/* wait time to next execution attempt */
	int nrun;	/* number running */
}
	qd = {100, 2, 60},		/* default values for queue defs */
	qt[NQUEUE];
static struct	queue	qq;

static struct runinfo
{
	pid_t	pid;
	short	que;
	struct  usr *rusr;	/* pointer to usr struct */
	char	*outfile;	/* file where stdout & stderr are trapped */
	short	jobtype;	/* what type of event: 0=cron, 1=at */
	char	*jobname;	/* command for "cron", jobname for "at" */
	int	mailwhendone;	/* 1 = send mail even if no ouptut */
	struct runinfo *next;
}	*rthead;

static struct miscpid {
	pid_t		pid;
	struct miscpid	*next;
}	*miscpid_head;

static pid_t cron_pid;	/* own pid */
static char didfork = 0; /* flag to see if I'm process group leader */
static int msgfd;	/* file descriptor for fifo queue */
static int ecid = 1;	/* event class id for el_remove(); MUST be set to 1 */
static int delayed;	/* is job being rescheduled or did it run first time */
static int cwd;		/* current working directory */
static struct event *next_event;	/* the next event to execute	*/
static struct usr *uhead;		/* ptr to the list of users	*/

/* Variables for error handling at reading crontabs. */
static char cte_intro[] = "Line(s) with errors:\n\n";
static char cte_trail1[] = "\nMax number of errors encountered.";
static char cte_trail2[] = " Evaluation of crontab aborted.\n";
static int cte_free = MAILBINITFREE;	/* Free buffer space */
static char *cte_text = NULL;		/* Text buffer pointer */
static char *cte_lp;			/* Next free line in cte_text */
static int cte_nvalid;			/* Valid lines found */

/* user's default environment for the shell */
#define	ROOTPATH	"PATH=/usr/sbin:/usr/bin"
#define	NONROOTPATH	"PATH=/usr/bin:"

static char *Def_supath	= NULL;
static char *Def_path		= NULL;
static char path[LINE_MAX]	= "PATH=";
static char supath[LINE_MAX]	= "PATH=";
static char homedir[LINE_MAX]	= ENV_HOME;
static char logname[LINE_MAX]	= "LOGNAME=";
static char tzone[LINE_MAX]	= ENV_TZ;
static char *envinit[] = {
	homedir,
	logname,
	ROOTPATH,
	"SHELL=/usr/bin/sh",
	tzone,
	NULL
};

extern char **environ;

#define	DEFTZ		"GMT"
static	int	log = 0;
static	char	hzname[10];

static void cronend(int);
static void thaw_handler(int);
static void child_handler(int);
static void child_sigreset(void);

static void mod_ctab(char *, time_t);
static void mod_atjob(char *, time_t);
static void add_atevent(struct usr *, char *, time_t, int);
static void rm_ctevents(struct usr *);
static void cleanup(struct runinfo *rn, int r);
static void crabort(char *, int);
static void msg(char *fmt, ...);
static void ignore_msg(char *, char *, struct event *);
static void logit(int, struct runinfo *, int);
static void parsqdef(char *);
static void defaults();
static void initialize(int);
static void quedefs(int);
static int idle(long);
static struct usr *find_usr(char *);
static int ex(struct event *e);
static void read_dirs(int);
static void mail(char *, char *, int);
static void readcron(struct usr *, time_t);
static int next_ge(int, char *);
static void free_if_unused(struct usr *);
static void del_atjob(char *, char *);
static void del_ctab(char *);
static void resched(int);
static int msg_wait(long);
static struct runinfo *rinfo_get(pid_t);
static void rinfo_free(struct runinfo *rp);
static void mail_result(struct usr *p, struct runinfo *pr, size_t filesize);
static time_t next_time(struct event *, time_t);
static time_t get_switching_time(int, time_t);
static time_t xmktime(struct tm *);
static void process_msg(struct message *, time_t);
static void reap_child(void);
static void miscpid_insert(pid_t);
static int miscpid_delete(pid_t);
static void contract_set_template(void);
static void contract_clear_template(void);
static void contract_abandon_latest(pid_t);

static void cte_init(void);
static void cte_add(int, char *);
static void cte_valid(void);
static int cte_istoomany(void);
static void cte_sendmail(char *);

static int set_user_cred(const struct usr *, struct project *);

static struct shared *create_shared_str(char *str);
static struct shared *dup_shared(struct shared *obj);
static void rel_shared(struct shared *obj);
static void *get_obj(struct shared *obj);
/*
 * last_time is set immediately prior to exection of an event (via ex())
 * to indicate the last time an event was executed.  This was (surely)
 * it's original intended use.
 */
static time_t last_time, init_time, t_old;
static int reset_needed; /* set to 1 when cron(8) needs to re-initialize */

static int		refresh;
static sigset_t		defmask, sigmask;

/*
 * BSM hooks
 */
extern int	audit_cron_session(char *, char *, uid_t, gid_t, char *);
extern void	audit_cron_new_job(char *, int, void *);
extern void	audit_cron_bad_user(char *);
extern void	audit_cron_user_acct_expired(char *);
extern int	audit_cron_create_anc_file(char *, char *, char *, uid_t);
extern int	audit_cron_delete_anc_file(char *, char *);
extern int	audit_cron_is_anc_name(char *);
extern int	audit_cron_mode();

static int cron_conv(int, struct pam_message **,
		struct pam_response **, void *);

static struct pam_conv pam_conv = {cron_conv, NULL};
static pam_handle_t *pamh;	/* Authentication handle */

/*
 * Function to help check a user's credentials.
 */

static int verify_user_cred(struct usr *u);

/*
 * Values returned by verify_user_cred and set_user_cred:
 */

#define	VUC_OK		0
#define	VUC_BADUSER	1
#define	VUC_NOTINGROUP	2
#define	VUC_EXPIRED	3
#define	VUC_NEW_AUTH	4

/*
 * Modes of process_anc_files function
 */
#define	CRON_ANC_DELETE	1
#define	CRON_ANC_CREATE	0

/*
 * Functions to remove a user or job completely from the running database.
 */
static void clean_out_atjobs(struct usr *u);
static void clean_out_ctab(struct usr *u);
static void clean_out_user(struct usr *u);
static void cron_unlink(char *name);
static void process_anc_files(int);

/*
 * functions in elm.c
 */
extern void el_init(int, time_t, time_t, int);
extern int el_add(void *, time_t, int);
extern void el_remove(int, int);
extern int el_empty(void);
extern void *el_first(void);
extern void el_delete(void);

static int valid_entry(char *, int);
static struct usr *create_ulist(char *, int);
static void init_cronevent(char *, int);
static void init_atevent(char *, time_t, int, int);
static void update_atevent(struct usr *, char *, time_t, int);

int
main(int argc, char *argv[])
{
	time_t t;
	time_t ne_time;		/* amt of time until next event execution */
	time_t newtime, lastmtime = 0L;
	struct usr *u;
	struct event *e, *e2, *eprev;
	struct stat buf;
	pid_t rfork;
	struct sigaction act;

	/*
	 * reset_needed is set to 1 whenever el_add() finds out that a cron
	 * job is scheduled to be run before the time when cron(8) daemon
	 * initialized.
	 * Other cases where a reset is needed is when ex() finds that the
	 * event to be executed is being run at the wrong time, or when idle()
	 * determines that time was reset.
	 * We immediately return to the top of the while (TRUE) loop in
	 * main() where the event list is cleared and rebuilt, and reset_needed
	 * is set back to 0.
	 */
	reset_needed = 0;

	/*
	 * Only the privileged user can run this command.
	 */
	if (getuid() != 0)
		crabort(NOTALLOWED, 0);

begin:
	(void) setlocale(LC_ALL, "");
	/* fork unless 'nofork' is specified */
	if ((argc <= 1) || (strcmp(argv[1], "nofork"))) {
		if ((rfork = fork()) != 0) {
			if (rfork == (pid_t)-1) {
				(void) sleep(30);
				goto begin;
			}
			return (0);
		}
		didfork++;
		(void) setpgrp();	/* detach cron from console */
	}

	(void) umask(022);
	(void) signal(SIGHUP, SIG_IGN);
	(void) signal(SIGINT, SIG_IGN);
	(void) signal(SIGQUIT, SIG_IGN);
	(void) signal(SIGTERM, cronend);

	defaults();
	initialize(1);
	quedefs(DEFAULT);	/* load default queue definitions */
	cron_pid = getpid();
	msg("*** cron started ***   pid = %d", cron_pid);

	/* setup THAW handler */
	act.sa_handler = thaw_handler;
	act.sa_flags = 0;
	(void) sigemptyset(&act.sa_mask);
	(void) sigaction(SIGTHAW, &act, NULL);

	/* setup CHLD handler */
	act.sa_handler = child_handler;
	act.sa_flags = 0;
	(void) sigemptyset(&act.sa_mask);
	(void) sigaddset(&act.sa_mask, SIGCLD);
	(void) sigaction(SIGCLD, &act, NULL);

	(void) sigemptyset(&defmask);
	(void) sigemptyset(&sigmask);
	(void) sigaddset(&sigmask, SIGCLD);
	(void) sigaddset(&sigmask, SIGTHAW);
	(void) sigprocmask(SIG_BLOCK, &sigmask, NULL);

	t_old = init_time;
	last_time = t_old;
	for (;;) {		/* MAIN LOOP */
		t = time(NULL);
		if ((t_old > t) || (t-last_time > CUSHION) || reset_needed) {
			reset_needed = 0;
			/*
			 * the time was set backwards or forward or
			 * refresh is requested.
			 */
			if (refresh)
				msg("re-scheduling jobs");
			else
				msg("time was reset, re-initializing");
			el_delete();
			u = uhead;
			while (u != NULL) {
				rm_ctevents(u);
				e = u->atevents;
				while (e != NULL) {
					free(e->cmd);
					e2 = e->link;
					free(e);
					e = e2;
				}
				u->atevents = NULL;
				u = u->nextusr;
			}
			(void) close(msgfd);
			initialize(0);
			t = time(NULL);
			last_time = t;
			/*
			 * reset_needed might have been set in the functions
			 * call path from initialize()
			 */
			if (reset_needed) {
				continue;
			}
		}
		t_old = t;

		if (next_event == NULL && !el_empty()) {
			next_event = (struct event *)el_first();
		}
		if (next_event == NULL) {
			ne_time = INFINITY;
		} else {
			ne_time = next_event->time - t;
#ifdef DEBUG
			cftime(timebuf, "%+", &next_event->time);
			(void) fprintf(stderr, "next_time=%ld %s\n",
			    next_event->time, timebuf);
#endif
		}
		if (ne_time > 0) {
			/*
			 * reset_needed may be set in the functions call path
			 * from idle()
			 */
			if (idle(ne_time) || reset_needed) {
				reset_needed = 1;
				continue;
			}
		}

		if (stat(QUEDEFS, &buf)) {
			msg("cannot stat QUEDEFS file");
		} else if (lastmtime != buf.st_mtime) {
			quedefs(LOAD);
			lastmtime = buf.st_mtime;
		}

		last_time = next_event->time; /* save execution time */

		/*
		 * reset_needed may be set in the functions call path
		 * from ex()
		 */
		if (ex(next_event) || reset_needed) {
			reset_needed = 1;
			continue;
		}

		switch (next_event->etype) {
		case CRONEVENT:
			/* add cronevent back into the main event list */
			if (delayed) {
				delayed = 0;
				break;
			}

			/*
			 * check if time(0)< last_time. if so, then the
			 * system clock has gone backwards. to prevent this
			 * job from being started twice, we reschedule this
			 * job for the >>next time after last_time<<, and
			 * then set next_event->time to this. note that
			 * crontab's resolution is 1 minute.
			 */

			if (last_time > time(NULL)) {
				msg(CLOCK_DRIFT);
				/*
				 * bump up to next 30 second
				 * increment
				 * 1 <= newtime <= 30
				 */
				newtime = 30 - (last_time % 30);
				newtime += last_time;

				/*
				 * get the next scheduled event,
				 * not the one that we just
				 * kicked off!
				 */
				next_event->time =
				    next_time(next_event, newtime);
				t_old = time(NULL);
			} else {
				next_event->time =
				    next_time(next_event, (time_t)0);
			}
#ifdef DEBUG
			cftime(timebuf, "%+", &next_event->time);
			(void) fprintf(stderr,
			    "pushing back cron event %s at %ld (%s)\n",
			    next_event->cmd, next_event->time, timebuf);
#endif

			switch (el_add(next_event, next_event->time,
			    (next_event->u)->ctid)) {
			case -1:
				ignore_msg("main", "cron", next_event);
				break;
			case -2: /* event time lower than init time */
				reset_needed = 1;
				break;
			}
			break;
		default:
			/* remove at or batch job from system */
			if (delayed) {
				delayed = 0;
				break;
			}
			eprev = NULL;
			e = (next_event->u)->atevents;
			while (e != NULL) {
				if (e == next_event) {
					if (eprev == NULL)
						(e->u)->atevents = e->link;
					else
						eprev->link = e->link;
					free(e->cmd);
					free(e);
					break;
				} else {
					eprev = e;
					e = e->link;
				}
			}
			break;
		}
		next_event = NULL;
	}

	/*NOTREACHED*/
}

static void
initialize(int firstpass)
{
#ifdef DEBUG
	(void) fprintf(stderr, "in initialize\n");
#endif
	if (firstpass) {
		/* for mail(1), make sure messages come from root */
		if (putenv("LOGNAME=root") != 0) {
			crabort("cannot expand env variable",
			    REMOVE_FIFO|CONSOLE_MSG);
		}
		if (access(FIFO, R_OK) == -1) {
			if (errno == ENOENT) {
				if (mknod(FIFO, S_IFIFO|0600, 0) != 0)
					crabort("cannot create fifo queue",
					    REMOVE_FIFO|CONSOLE_MSG);
			} else {
				if (NOFORK) {
					/* didn't fork... init(8) is waiting */
					(void) sleep(60);
				}
				perror("FIFO");
				crabort("cannot access fifo queue",
				    REMOVE_FIFO|CONSOLE_MSG);
			}
		} else {
			if (NOFORK) {
				/* didn't fork... init(8) is waiting */
				(void) sleep(60);
				/*
				 * the wait is painful, but we don't want
				 * init respawning this quickly
				 */
			}
			crabort("cannot start cron; FIFO exists", CONSOLE_MSG);
		}
	}

	if ((msgfd = open(FIFO, O_RDWR)) < 0) {
		perror("! open");
		crabort("cannot open fifo queue", REMOVE_FIFO|CONSOLE_MSG);
	}

	init_time = time(NULL);
	el_init(8, init_time, (time_t)(60*60*24), 10);

	init_time = time(NULL);
	el_init(8, init_time, (time_t)(60*60*24), 10);

	/*
	 * read directories, create users list, and add events to the
	 * main event list. Only zero user list on firstpass.
	 */
	if (firstpass)
		uhead = NULL;
	read_dirs(firstpass);
	next_event = NULL;

	if (!firstpass)
		return;

	/* stdout is log file */
	if (freopen(ACCTFILE, "a", stdout) == NULL)
		(void) fprintf(stderr, "cannot open %s\n", ACCTFILE);

	/* log should be root-only */
	(void) fchmod(1, S_IRUSR|S_IWUSR);

	/* stderr also goes to ACCTFILE */
	(void) close(fileno(stderr));
	(void) dup(1);
	/* null for stdin */
	(void) freopen("/dev/null", "r", stdin);

	contract_set_template();
}

static void
read_dirs(int first)
{
	DIR		*dir;
	struct dirent	*dp;
	char		*ptr;
	int		jobtype;
	time_t		tim;


	if (chdir(CRONDIR) == -1)
		crabort(BADCD, REMOVE_FIFO|CONSOLE_MSG);
	cwd = CRON;
	if ((dir = opendir(".")) == NULL)
		crabort(NOREADDIR, REMOVE_FIFO|CONSOLE_MSG);
	while ((dp = readdir(dir)) != NULL) {
		if (!valid_entry(dp->d_name, CRONEVENT))
			continue;
		init_cronevent(dp->d_name, first);
	}
	(void) closedir(dir);

	if (chdir(ATDIR) == -1) {
		msg("cannot chdir to at directory");
		return;
	}
	if ((dir = opendir(".")) == NULL) {
		msg("cannot read at at directory");
		return;
	}
	cwd = AT;
	while ((dp = readdir(dir)) != NULL) {
		if (!valid_entry(dp->d_name, ATEVENT))
			continue;
		ptr = dp->d_name;
		if (((tim = num(&ptr)) == 0) || (*ptr != '.'))
			continue;
		ptr++;
		if (!isalpha(*ptr))
			continue;
		jobtype = *ptr - 'a';
		if (jobtype >= NQUEUE) {
			cron_unlink(dp->d_name);
			continue;
		}
		init_atevent(dp->d_name, tim, jobtype, first);
	}
	(void) closedir(dir);
}

static int
valid_entry(char *name, int type)
{
	struct stat	buf;

	if (strcmp(name, ".") == 0 ||
	    strcmp(name, "..") == 0)
		return (0);

	/* skip over ancillary file names */
	if (audit_cron_is_anc_name(name))
		return (0);

	if (stat(name, &buf)) {
		mail(name, BADSTAT, ERR_UNIXERR);
		cron_unlink(name);
		return (0);
	}
	if (!S_ISREG(buf.st_mode)) {
		mail(name, BADTYPE, ERR_NOTREG);
		cron_unlink(name);
		return (0);
	}
	if (type == ATEVENT) {
		if (!(buf.st_mode & ISUID)) {
			cron_unlink(name);
			return (0);
		}
	}
	return (1);
}

struct usr *
create_ulist(char *name, int type)
{
	struct usr	*u;

	u = xcalloc(1, sizeof (struct usr));
	u->name = xstrdup(name);
	if (type == CRONEVENT) {
		u->ctexists = TRUE;
		u->ctid = ecid++;
	} else {
		u->ctexists = FALSE;
		u->ctid = 0;
	}
	u->uid = (uid_t)-1;
	u->gid = (uid_t)-1;
	u->nextusr = uhead;
	uhead = u;
	return (u);
}

void
init_cronevent(char *name, int first)
{
	struct usr	*u;

	if (first) {
		u = create_ulist(name, CRONEVENT);
		readcron(u, 0);
	} else {
		if ((u = find_usr(name)) == NULL) {
			u = create_ulist(name, CRONEVENT);
			readcron(u, 0);
		} else {
			u->ctexists = TRUE;
			rm_ctevents(u);
			el_remove(u->ctid, 0);
			readcron(u, 0);
		}
	}
}

void
init_atevent(char *name, time_t tim, int jobtype, int first)
{
	struct usr	*u;

	if (first) {
		u = create_ulist(name, ATEVENT);
		add_atevent(u, name, tim, jobtype);
	} else {
		if ((u = find_usr(name)) == NULL) {
			u = create_ulist(name, ATEVENT);
			add_atevent(u, name, tim, jobtype);
		} else {
			update_atevent(u, name, tim, jobtype);
		}
	}
}

static void
mod_ctab(char *name, time_t reftime)
{
	struct	passwd	*pw;
	struct	stat	buf;
	struct	usr	*u;
	char	namebuf[LINE_MAX];
	char	*pname;

	/* skip over ancillary file names */
	if (audit_cron_is_anc_name(name))
		return;

	if ((pw = getpwnam(name)) == NULL) {
		msg("No such user as %s - cron entries not created", name);
		return;
	}
	if (cwd != CRON) {
		if (snprintf(namebuf, sizeof (namebuf), "%s/%s",
		    CRONDIR, name) >= sizeof (namebuf)) {
			msg("Too long path name %s - cron entries not created",
			    namebuf);
			return;
		}
		pname = namebuf;
	} else {
		pname = name;
	}
	/*
	 * a warning message is given by the crontab command so there is
	 * no need to give one here......  use this code if you only want
	 * users with a login shell of /usr/bin/sh to use cron
	 */
#ifdef BOURNESHELLONLY
	if ((strcmp(pw->pw_shell, "") != 0) &&
	    (strcmp(pw->pw_shell, SHELL) != 0)) {
		mail(name, BADSHELL, ERR_CANTEXECCRON);
		cron_unlink(pname);
		return;
	}
#endif
	if (stat(pname, &buf)) {
		mail(name, BADSTAT, ERR_UNIXERR);
		cron_unlink(pname);
		return;
	}
	if (!S_ISREG(buf.st_mode)) {
		mail(name, BADTYPE, ERR_CRONTABENT);
		return;
	}
	if ((u = find_usr(name)) == NULL) {
#ifdef DEBUG
		(void) fprintf(stderr, "new user (%s) with a crontab\n", name);
#endif
		u = create_ulist(name, CRONEVENT);
		u->home = xmalloc(strlen(pw->pw_dir) + 1);
		(void) strcpy(u->home, pw->pw_dir);
		u->uid = pw->pw_uid;
		u->gid = pw->pw_gid;
		readcron(u, reftime);
	} else {
		u->uid = pw->pw_uid;
		u->gid = pw->pw_gid;
		if (u->home != NULL) {
			if (strcmp(u->home, pw->pw_dir) != 0) {
				free(u->home);
				u->home = xmalloc(strlen(pw->pw_dir) + 1);
				(void) strcpy(u->home, pw->pw_dir);
			}
		} else {
			u->home = xmalloc(strlen(pw->pw_dir) + 1);
			(void) strcpy(u->home, pw->pw_dir);
		}
		u->ctexists = TRUE;
		if (u->ctid == 0) {
#ifdef DEBUG
			(void) fprintf(stderr, "%s now has a crontab\n",
			    u->name);
#endif
			/* user didnt have a crontab last time */
			u->ctid = ecid++;
			u->ctevents = NULL;
			readcron(u, reftime);
			return;
		}
#ifdef DEBUG
		(void) fprintf(stderr, "%s has revised their crontab\n",
		    u->name);
#endif
		rm_ctevents(u);
		el_remove(u->ctid, 0);
		readcron(u, reftime);
	}
}

static void
mod_atjob(char *name, time_t reftime __unused)
{
	char	*ptr;
	time_t	tim;
	struct	passwd	*pw;
	struct	stat	buf;
	struct	usr	*u;
	char	namebuf[PATH_MAX];
	char	*pname;
	int	jobtype;

	ptr = name;
	if (((tim = num(&ptr)) == 0) || (*ptr != '.'))
		return;
	ptr++;
	if (!isalpha(*ptr))
		return;
	jobtype = *ptr - 'a';

	/* check for audit ancillary file */
	if (audit_cron_is_anc_name(name))
		return;

	if (cwd != AT) {
		if (snprintf(namebuf, sizeof (namebuf), "%s/%s", ATDIR, name)
		    >= sizeof (namebuf)) {
			return;
		}
		pname = namebuf;
	} else {
		pname = name;
	}
	if (stat(pname, &buf) || jobtype >= NQUEUE) {
		cron_unlink(pname);
		return;
	}
	if (!(buf.st_mode & ISUID) || !S_ISREG(buf.st_mode)) {
		cron_unlink(pname);
		return;
	}
	if ((pw = getpwuid(buf.st_uid)) == NULL) {
		cron_unlink(pname);
		return;
	}
	/*
	 * a warning message is given by the at command so there is no
	 * need to give one here......use this code if you only want
	 * users with a login shell of /usr/bin/sh to use cron
	 */
#ifdef BOURNESHELLONLY
	if ((strcmp(pw->pw_shell, "") != 0) &&
	    (strcmp(pw->pw_shell, SHELL) != 0)) {
		mail(pw->pw_name, BADSHELL, ERR_CANTEXECAT);
		cron_unlink(pname);
		return;
	}
#endif
	if ((u = find_usr(pw->pw_name)) == NULL) {
#ifdef DEBUG
		(void) fprintf(stderr, "new user (%s) with an at job = %s\n",
		    pw->pw_name, name);
#endif
		u = create_ulist(pw->pw_name, ATEVENT);
		u->home = xstrdup(pw->pw_dir);
		u->uid = pw->pw_uid;
		u->gid = pw->pw_gid;
		add_atevent(u, name, tim, jobtype);
	} else {
		u->uid = pw->pw_uid;
		u->gid = pw->pw_gid;
		free(u->home);
		u->home = xstrdup(pw->pw_dir);
		update_atevent(u, name, tim, jobtype);
	}
}

static void
add_atevent(struct usr *u, char *job, time_t tim, int jobtype)
{
	struct event *e;

	e = xmalloc(sizeof (struct event));
	e->etype = jobtype;
	e->cmd = xmalloc(strlen(job) + 1);
	(void) strcpy(e->cmd, job);
	e->u = u;
	e->link = u->atevents;
	u->atevents = e;
	e->of.at.exists = TRUE;
	e->of.at.eventid = ecid++;
	if (tim < init_time)	/* old job */
		e->time = init_time;
	else
		e->time = tim;
#ifdef DEBUG
	(void) fprintf(stderr, "add_atevent: user=%s, job=%s, time=%ld\n",
	    u->name, e->cmd, e->time);
#endif
	if (el_add(e, e->time, e->of.at.eventid) < 0) {
		ignore_msg("add_atevent", "at", e);
	}
}

void
update_atevent(struct usr *u, char *name, time_t tim, int jobtype)
{
	struct event *e;

	e = u->atevents;
	while (e != NULL) {
		if (strcmp(e->cmd, name) == 0) {
			e->of.at.exists = TRUE;
			break;
		} else {
			e = e->link;
		}
	}
	if (e == NULL) {
#ifdef DEBUG
		(void) fprintf(stderr, "%s has a new at job = %s\n",
		    u->name, name);
#endif
			add_atevent(u, name, tim, jobtype);
	}
}

static char line[CTLINESIZE];	/* holds a line from a crontab file */
static int cursor;		/* cursor for the above line */

static void
readcron(struct usr *u, time_t reftime)
{
	/*
	 * readcron reads in a crontab file for a user (u). The list of
	 * events for user u is built, and u->events is made to point to
	 * this list. Each event is also entered into the main event
	 * list.
	 */
	FILE *cf;	/* cf will be a user's crontab file */
	struct event *e;
	int start;
	unsigned int i;
	char namebuf[PATH_MAX];
	char *pname;
	struct shared *tz = NULL;
	struct shared *home = NULL;
	struct shared *shell = NULL;
	uint32_t max_random_delay = 0;
	int lineno = 0;
	const char *errstr;

	/* read the crontab file */
	cte_init();		/* Init error handling */
	if (cwd != CRON) {
		if (snprintf(namebuf, sizeof (namebuf), "%s/%s",