/*      $NetBSD: rmjob.c,v 1.25 2009/07/13 19:05:41 roy Exp $   */

/*
 * Copyright (c) 1983, 1993
 *      The Regents of the University of California.  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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)rmjob.c     8.2 (Berkeley) 4/28/95";
#else
__RCSID("$NetBSD: rmjob.c,v 1.25 2009/07/13 19:05:41 roy Exp $");
#endif
#endif /* not lint */

#include <sys/param.h>

#include <signal.h>
#include <errno.h>
#include <dirent.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include "lp.h"
#include "lp.local.h"
#include "pathnames.h"

/*
 * rmjob - remove the specified jobs from the queue.
 */

/*
 * Stuff for handling lprm specifications
 */
extern char     *user[];                /* users to process */
extern int      users;                  /* # of users in user array */
extern int      requ[];                 /* job number of spool entries */
extern int      requests;               /* # of spool requests */
extern char     *person;                /* name of person doing lprm */

static char     root[] = "root";
static int      all = 0;                /* eliminate all files (root only) */
static int      cur_daemon;             /* daemon's pid */
static char     current[40];            /* active control file name */

extern uid_t    uid, euid;              /* real and effective user id's */

static  void    do_unlink(const char *);
static  void    alarmer(int);

void
rmjob(void)
{
        int i, nitems;
        int assasinated = 0;
        struct dirent **files;

        getprintcap(printer);

        /*
         * If the format was `lprm -' and the user isn't the super-user,
         *  then fake things to look like he said `lprm user'.
         */
        if (users < 0) {
                if (getuid() == 0)
                        all = 1;        /* all files in local queue */
                else {
                        user[0] = person;
                        users = 1;
                }
        }
        if (!strcmp(person, "-all")) {
                if (from == host)
                        fatal("The login name \"-all\" is reserved");
                all = 1;        /* all those from 'from' */
                person = root;
        }

        seteuid(euid);
        if (chdir(SD) < 0)
                fatal("cannot chdir to spool directory");
        if ((nitems = scandir(".", &files, iscf, NULL)) < 0)
                fatal("cannot access spool directory");
        seteuid(uid);

        if (nitems) {
                /*
                 * Check for an active printer daemon (in which case we
                 *  kill it if it is reading our file) then remove stuff
                 *  (after which we have to restart the daemon).
                 */
                if (lockchk(LO) && chk(current)) {
                        seteuid(euid);
                        assasinated = kill(cur_daemon, SIGINT) == 0;
                        seteuid(uid);
                        if (!assasinated)
                                fatal("cannot kill printer daemon");
                }
                /*
                 * process the files
                 */
                for (i = 0; i < nitems; i++)
                        process(files[i]->d_name);
        }
        rmremote();
        /*
         * Restart the printer daemon if it was killed
         */
        if (assasinated && !startdaemon(printer))
                fatal("cannot restart printer daemon\n");
        exit(0);
}

/*
 * Process a lock file: collect the pid of the active
 *  daemon and the file name of the active spool entry.
 * Return boolean indicating existence of a lock file.
 */
int
lockchk(const char *s)
{
        FILE *fp;
        int i, n;

        seteuid(euid);
        if ((fp = fopen(s, "r")) == NULL) {
                if (errno == EACCES)
                        fatal("can't access lock file");
                else
                        return(0);
        }
        seteuid(uid);
        if (!get_line(fp)) {
                (void)fclose(fp);
                return(0);              /* no daemon present */
        }
        cur_daemon = atoi(line);
        if (kill(cur_daemon, 0) < 0 && errno != EPERM) {
                (void)fclose(fp);
                return(0);              /* no daemon present */
        }
        for (i = 1; (n = fread(current, sizeof(char), sizeof(current), fp)) <= 0; i++) {
                if (i > 5) {
                        n = 1;
                        break;
                }
                sleep((size_t)i);
        }
        current[n-1] = '\0';
        (void)fclose(fp);
        return(1);
}

/*
 * Process a control file.
 */
void
process(const char *file)
{
        FILE *cfp;

        if (!chk(file))
                return;
        seteuid(euid);
        if ((cfp = fopen(file, "r")) == NULL)
                fatal("cannot open %s", file);
        seteuid(uid);
        while (get_line(cfp)) {
                switch (line[0]) {
                case 'U':  /* unlink associated files */
                        if (strchr(line+1, '/') || strncmp(line+1, "df", 2))
                                break;
                        do_unlink(line+1);
                }
        }
        (void)fclose(cfp);
        do_unlink(file);
}

static void
do_unlink(const char *file)
{
        int     ret;

        if (from != host)
                printf("%s: ", host);
        seteuid(euid);
        ret = unlink(file);
        seteuid(uid);
        printf(ret ? "cannot dequeue %s\n" : "%s dequeued\n", file);
}

/*
 * Do the dirty work in checking
 */
int
chk(const char *file)
{
        int *r, n;
        char **u;
        const char *cp;
        FILE *cfp;

        /*
         * Check for valid cf file name (mostly checking current).
         */
        if (strlen(file) < 7 || file[0] != 'c' || file[1] != 'f')
                return(0);

        if (all && (from == host || !strcmp(from, file+6)))
                return(1);

        /*
         * get the owner's name from the control file.
         */
        seteuid(euid);
        if ((cfp = fopen(file, "r")) == NULL)
                return(0);
        seteuid(uid);
        while (get_line(cfp)) {
                if (line[0] == 'P')
                        break;
        }
        (void)fclose(cfp);
        if (line[0] != 'P')
                return(0);

        if (users == 0 && requests == 0)
                return(!strcmp(file, current) && isowner(line+1, file));
        /*
         * Check the request list
         */
        for (n = 0, cp = file+3; isdigit((unsigned char)*cp); )
                n = n * 10 + (*cp++ - '0');
        for (r = requ; r < &requ[requests]; r++)
                if (*r == n && isowner(line+1, file))
                        return(1);
        /*
         * Check to see if it's in the user list
         */
        for (u = user; u < &user[users]; u++)
                if (!strcmp(*u, line+1) && isowner(line+1, file))
                        return(1);
        return(0);
}

/*
 * If root is removing a file on the local machine, allow it.
 * If root is removing a file from a remote machine, only allow
 * files sent from the remote machine to be removed.
 * Normal users can only remove the file from where it was sent.
 */
int
isowner(const char *owner, const char *file)
{
        if (!strcmp(person, root) && (from == host || !strcmp(from, file+6)))
                return(1);
        if (!strcmp(person, owner) && !strcmp(from, file+6))
                return(1);
        if (from != host)
                printf("%s: ", host);
        printf("%s: Permission denied\n", file);
        return(0);
}

/*
 * Check to see if we are sending files to a remote machine. If we are,
 * then try removing files on the remote machine.
 */
void
rmremote(void)
{
        char *cp, *s;
        int i, rem;
        size_t len;

        if (!remote)
                return; /* not sending to a remote machine */

        /*
         * Flush stdout so the user can see what has been deleted
         * while we wait (possibly) for the connection.
         */
        fflush(stdout);

        /* \5 RP space all */
        len = 1 + strlen(RP) + 1 + strlen(all ? "-all" : person);
        for (i = 0; i < users; i++) {
                len += strlen(user[i]) + 1;
        }
        for (i = 0; i < requests; i++) {
                len += snprintf(line, sizeof(line), " %d", requ[i]);
        }
        /* newline nul */
        len += 2;
        if (len > sizeof(line))
                s = malloc(len);
        else    
                s = line;
        cp = s;

        cp += snprintf(s, len, "\5%s %s", RP, all ? "-all" : person);
        for (i = 0; i < users; i++) {
                *cp++ = ' ';
                strncpy(cp, user[i], len - (cp - s) - 2);
                cp += strlen(cp);
        }
        for (i = 0; i < requests; i++) {
                (void)snprintf(cp, len - (cp - s) - 1, " %d", requ[i]);
                cp += strlen(cp);
        }
        cp[0] = '\n';
        cp[1] = '\0';

        rem = getport(RM);
        if (rem < 0) {
                if (from != host)
                        printf("%s: ", host);
                printf("connection to %s is down\n", RM);
        } else {
                struct sigaction osa, nsa;

                if ((size_t)write(rem, s, len) != len)
                        fatal("Lost connection");
                if (len > sizeof(line))
                        (void)free(s);
                nsa.sa_handler = alarmer;
                sigemptyset(&nsa.sa_mask);
                sigaddset(&nsa.sa_mask, SIGALRM);
                nsa.sa_flags = 0;
                (void)sigaction(SIGALRM, &nsa, &osa);
                alarm(wait_time);
                while ((i = read(rem, line, sizeof(line))) > 0) {
                        (void)fwrite(line, 1, (size_t)i, stdout);
                        alarm(wait_time);
                }
                alarm(0);
                (void)sigaction(SIGALRM, &osa, NULL);
                (void)close(rem);
        }
}

static void
alarmer(int s)
{
        /* nothing */
}

/*
 * Return 1 if the filename begins with 'cf'
 */
int
iscf(const struct dirent *d)
{
        return(d->d_name[0] == 'c' && d->d_name[1] == 'f');
}