/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 * Copyright (c) 2016 by Delphix. All rights reserved.
 */

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


/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

/*
 *      synopsis: atrm [-f] [-i] [-a] [[job #] [user] ...]
 *
 *
 *      Remove "at" jobs.
 */

#include <stdio.h>
#include <pwd.h>
#include <ctype.h>
#include <sys/types.h>
#include <dirent.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <errno.h>
#include <unistd.h>
#include <locale.h>
#include <strings.h>
#include <stdlib.h>
#include <libintl.h>
#include "cron.h"
#include "getresponse.h"

extern time_t   num();
extern char     *errmsg();
extern void     audit_at_delete(char *, char *, int);

#define SUPERUSER       0                       /* is user super-user? */
#define CANTCD          "can't change directory to the at directory"
#define NOREADDIR       "can't read the at directory"

uid_t user;                                     /* person requesting removal */
int fflag = 0;                                  /* suppress announcements? */
int iflag = 0;                                  /* run interactively? */

char login[UNAMESIZE];
char login_authchk[UNAMESIZE]; /* used for authorization checks */

#define INVALIDUSER     "you are not a valid user (no entry in /etc/passwd)"
#define NOTALLOWED      "you are not authorized to use at.  Sorry."
#define NAMETOOLONG     "login name too long"

static void usage(void);
static void atabortperror(char *msg);
static void atabort(char *msg);
static void atperror(char *msg);
static void atperror2(char *msg, char *name);
static void aterror(char *msg);
static void powner(char *file);

int     getjoblist(struct dirent ***, struct stat ***, int (*)());
int     removentry(char *, struct stat *, uid_t);

int
main(int argc, char **argv)
{
        int i;                          /* for loop index */
        int numjobs;                    /* # of jobs in spooling area */
        int allflag = 0;                /* remove all jobs belonging to user? */
        int jobexists;                  /* does a requested job exist? */
        char *pp;
        struct dirent **namelist;       /* names of jobs in spooling area */
        struct stat **statlist;
        struct passwd *pwd;

        /*
         * If job number, user name, or "-" is not specified, just print
         * usage info and exit.
         */
        (void) setlocale(LC_ALL, "");
        (void) textdomain(TEXT_DOMAIN);
        if (argc < 2)
                usage();

        --argc; ++argv;

        pp = getuser((user = getuid()));
        if (pp == NULL)
                atabort(INVALIDUSER);
        if (strlcpy(login, pp, sizeof (login)) >= sizeof (login))
                atabort(NAMETOOLONG);
        if (strlcpy(login_authchk, pp, sizeof (login_authchk))
            >= sizeof (NAMETOOLONG))
                atabort(INVALIDUSER);
        if (!allowed(login, ATALLOW, ATDENY))
                atabort(NOTALLOWED);

        /*
         * Process command line flags.
         * Special case the "-" option so that others may be grouped.
         */
        while (argc > 0 && **argv == '-') {
                *(*argv)++;
                while (**argv) {
                        switch (*(*argv)++) {

                        case 'a':       ++allflag;
                                        break;

                        case 'f':       ++fflag;
                                        break;

                        case 'i':       ++iflag;
                                        break;

                        default:        usage();
                        }
                }
                ++argv; --argc;
        }

        /*
         * If all jobs are to be removed and extra command line arguments
         * are given, print usage info and exit.
         */
        if (allflag && argc)
                usage();

        /*
         * If only certain jobs are to be removed and no job #'s or user
         * names are specified, print usage info and exit.
         */
        if (!allflag && !argc)
                usage();

        /*
         * If interactive removal and quiet removal are requested, override
         * quiet removal and run interactively.
         */
        if (iflag && fflag)
                fflag = 0;


        /*
         * Move to spooling directory and get a list of the files in the
         * spooling area.
         */
        numjobs = getjoblist(&namelist, &statlist, strcmp);
        /*
         * If all jobs belonging to the user are to be removed, compare
         * the user's id to the owner of the file. If they match, remove
         * the file. If the user is the super-user, don't bother comparing
         * the id's. After all files are removed, exit (status 0).
         */
        if (allflag) {
                for (i = 0; i < numjobs; ++i) {
                        if (cron_admin(login_authchk) ||
                            user == statlist[i]->st_uid)
                                (void) removentry(namelist[i]->d_name,
                                    statlist[i], user);
                }
                exit(0);
        }

        /*
         * If only certain jobs are to be removed, interpret each command
         * line argument. A check is done to see if it is a user's name or
         * a job number (inode #). If it's a user's name, compare the argument
         * to the files owner. If it's a job number, compare the argument to
         * the file name. In either case, if a match occurs, try to
         * remove the file.
         */

        while (argc--) {
                jobexists = 0;
                for (i = 0; i < numjobs; ++i) {

                        /* if the inode number is 0, this entry was removed */
                        if (statlist[i]->st_ino == 0)
                                continue;

                        /*
                         * if argv is a username, compare their uid to
                         * the uid of the owner of the file......
                         */
                        if (pwd = getpwnam(*argv)) {
                                if (statlist[i]->st_uid != pwd->pw_uid)
                                        continue;
                        /*
                         * otherwise, we assume that the argv is a job # and
                         * thus compare argv to the file name.
                         */
                        } else {
                                if (strcmp(namelist[i]->d_name, *argv))
                                        continue;
                        }
                        ++jobexists;
                        /*
                         * if the entry is ultimately removed, don't
                         * try to remove it again later.
                         */
                        if (removentry(namelist[i]->d_name, statlist[i],
                            user)) {
                                statlist[i]->st_ino = 0;
                        }
                }

                /*
                 * If a requested argument doesn't exist, print a message.
                 */
                if (!jobexists && !fflag) {
                        fprintf(stderr, "atrm: %s: no such job number\n",
                            *argv);
                }
                ++argv;
        }
        return (0);
}

/*
 * Print usage info and exit.
 */
static void
usage(void)
{
        fprintf(stderr, "usage: atrm [-f] [-i] [-a] [[job #] [user] ...]\n");
        exit(1);
}


/*
 * Remove an entry from the queue. The access of the file is checked for
 * write permission (since all jobs are mode 644). If access is granted,
 * unlink the file. If the fflag (suppress announcements) is not set,
 * print the job number that we are removing and the result of the access
 * check (either "permission denied" or "removed"). If we are running
 * interactively (iflag), prompt the user before we unlink the file. If
 * the super-user is removing jobs, inform them who owns each file before
 * it is removed.  Return TRUE if file removed, else FALSE.
 */
int
removentry(char *filename, struct stat *statptr, uid_t user)
{
        struct passwd *pwd;
        char *pp;
        int r;

        if (init_yes() < 0) {
                (void) fprintf(stderr, gettext(ERR_MSG_INIT_YES),
                    strerror(errno));
                exit(1);
        }

        if (!fflag)
                printf("%s: ", filename);

        if (user != statptr->st_uid && !cron_admin(login_authchk)) {

                if (!fflag) {
                        printf("permission denied\n");
                }
                return (0);

        } else {
                if (iflag) {
                        if (cron_admin(login_authchk)) {
                                printf("\t(owned by ");
                                powner(filename);
                                printf(") ");
                        }
                        printf(gettext("remove it? "));
                        if (yes() == 0)
                                return (0);
                }

                if (cron_admin(login_authchk)) {
                        pp = getuser((uid_t)statptr->st_uid);
                        if (pp == NULL)
                                atabort(INVALIDUSER);
                        if (strlcpy(login, pp, sizeof (login)) >=
                            sizeof (login))
                                atabort(NAMETOOLONG);
                }
                cron_sendmsg(DELETE, login, filename, AT);
                if ((r = unlink(filename)) < 0) {
                        if (!fflag) {
                                fputs("could not remove\n", stdout);
                                (void) fprintf(stderr, "atrm: %s: %s\n",
                                    filename, errmsg(errno));
                        }
                        audit_at_delete(filename, NULL, r);
                        return (0);
                }
                audit_at_delete(filename, NULL, r);
                if (!fflag && !iflag)
                        printf("removed\n");
                return (1);
        }
}

/*
 * Print the owner of the job. This is the owner of the spoolfile.
 * If we run into trouble getting the name, we'll just print "???".
 */
static void
powner(char *file)
{
        struct stat statb;
        char *getname();

        if (stat(file, &statb) < 0) {
                printf("%s", "???");
                (void) fprintf(stderr, "atrm: Couldn't stat spoolfile %s: %s\n",
                    file, errmsg(errno));
                return;
        }

        printf("%s", getname(statb.st_uid));
}


int
getjoblist(struct dirent ***namelistp, struct stat ***statlistp,
    int (*sortfunc)())
{
        int numjobs;
        struct dirent **namelist;
        int i;
        struct stat *statptr;   /* pointer to file stat structure */
        struct stat **statlist;
        extern int filewanted();        /* should a file be listed in queue? */
        if (chdir(ATDIR) < 0)
                atabortperror(CANTCD);

        /*
         * Get a list of the files in the spooling area.
         */
        if ((numjobs = scandir(".", namelistp, filewanted, sortfunc)) < 0)
                atabortperror(NOREADDIR);

        if ((statlist =
            (struct stat **)malloc(numjobs * sizeof (struct stat ***)))
            == NULL)
                atabort("Out of memory");

        namelist = *namelistp;

        /*
         * Build an array of pointers to the file stats for all jobs in
         * the spooling area.
         */
        for (i = 0; i < numjobs; ++i) {
                statptr = (struct stat *)malloc(sizeof (struct stat));
                if (statptr == NULL)
                        atabort("Out of memory");
                if (stat(namelist[i]->d_name, statptr) < 0) {
                        atperror2("Can't stat", namelist[i]->d_name);
                        continue;
                }
                statlist[i] = statptr;
        }

        *statlistp = statlist;
        return (numjobs);
}

/*
 * Get the full login name of a person using their user id.
 */
char *
getname(uid_t uid)
{
        struct passwd *pwdinfo;         /* password info structure */


        if ((pwdinfo = getpwuid(uid)) == 0)
                return ("???");
        return (pwdinfo->pw_name);
}

static void
aterror(char *msg)
{
        fprintf(stderr, "atrm: %s\n", msg);
}

static void
atperror(char *msg)
{
        fprintf(stderr, "atrm: %s: %s\n", msg, errmsg(errno));
}

static void
atperror2(char *msg, char *name)
{
        fprintf(stderr, "atrm: %s %s: %s\n", msg, name, errmsg(errno));
}

static void
atabort(char *msg)
{
        aterror(msg);
        exit(1);
}

static void
atabortperror(char *msg)
{
        atperror(msg);
        exit(1);
}