/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * 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 "lp.cdefs.h"           /* A cross-platform version of <sys/cdefs.h> */
#include <sys/param.h>
#include <sys/uio.h>

#include <ctype.h>
#include <dirent.h>
#include <err.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define psignal foil_gcc_psignal
#define sys_siglist foil_gcc_siglist
#include <unistd.h>
#undef psignal
#undef sys_siglist

#include "lp.h"
#include "lp.local.h"
#include "pathnames.h"

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

/*
 * Stuff for handling lprm specifications
 */
static char     root[] = "root";
static int      all = 0;                /* eliminate all files (root only) */
static int      cur_daemon;             /* daemon's pid */
static char     current[7+MAXHOSTNAMELEN];  /* active control file name */

static  void    alarmhandler(int _signo);
static  void    do_unlink(char *_file);
static int       isowner(char *_owner, char *_file, const char *_cfhost);

void
rmjob(const char *printer)
{
        register int i, nitems;
        int assassinated = 0;
        struct dirent **files;
        char *cp;
        struct printer myprinter, *pp = &myprinter;

        init_printer(pp);
        if ((i = getprintcap(printer, pp)) < 0)
                fatal(pp, "getprintcap: %s", pcaperr(i));
        if ((cp = checkremote(pp))) {
                printf("Warning: %s\n", cp);
                free(cp);
        }

        /*
         * 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 == local_host)
                        fatal(pp, "The login name \"-all\" is reserved");
                all = 1;        /* all those from 'from_host' */
                person = root;
        }

        PRIV_START
        if (chdir(pp->spool_dir) < 0)
                fatal(pp, "cannot chdir to spool directory");
        if ((nitems = scandir(".", &files, iscf, NULL)) < 0)
                fatal(pp, "cannot access spool directory");
        PRIV_END

        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(pp, pp->lock_file) && chk(current)) {
                        PRIV_START
                        assassinated = kill(cur_daemon, SIGINT) == 0;
                        PRIV_END
                        if (!assassinated)
                                fatal(pp, "cannot kill printer daemon");
                }
                /*
                 * process the files
                 */
                for (i = 0; i < nitems; i++)
                        process(pp, files[i]->d_name);
        }
        rmremote(pp);
        /*
         * Restart the printer daemon if it was killed
         */
        if (assassinated && !startdaemon(pp))
                fatal(pp, "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(struct printer *pp, char *slockf)
{
        register FILE *fp;
        register int i, n;

        PRIV_START
        if ((fp = fopen(slockf, "r")) == NULL) {
                if (errno == EACCES)
                        fatal(pp, "%s: %s", slockf, strerror(errno));
                else
                        return(0);
        }
        PRIV_END
        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(i);
        }
        current[n-1] = '\0';
        (void) fclose(fp);
        return(1);
}

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

        if (!chk(file))
                return;
        PRIV_START
        if ((cfp = fopen(file, "r")) == NULL)
                fatal(pp, "cannot open %s", file);
        PRIV_END
        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(char *file)
{
        int     ret;

        if (from_host != local_host)
                printf("%s: ", local_host);
        PRIV_START
        ret = unlink(file);
        PRIV_END
        printf(ret ? "cannot dequeue %s\n" : "%s dequeued\n", file);
}

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

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

        jnum = calc_jobnum(file, &cfhost);
        if (all && (from_host == local_host || !strcmp(from_host, cfhost)))
                return(1);

        /*
         * get the owner's name from the control file.
         */
        PRIV_START
        if ((cfp = fopen(file, "r")) == NULL)
                return(0);
        PRIV_END
        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, cfhost));
        /*
         * Check the request list
         */
        for (r = requ; r < &requ[requests]; r++)
                if (*r == jnum && isowner(line+1, file, cfhost))
                        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, cfhost))
                        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.
 */
static int
isowner(char *owner, char *file, const char *cfhost)
{
        if (!strcmp(person, root) && (from_host == local_host ||
            !strcmp(from_host, cfhost)))
                return (1);
        if (!strcmp(person, owner) && !strcmp(from_host, cfhost))
                return (1);
        if (from_host != local_host)
                printf("%s: ", local_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(const struct printer *pp)
{
        int i, elem, firstreq, niov, rem, totlen;
        char buf[BUFSIZ];
        void (*savealrm)(int);
        struct iovec *iov;

        if (!pp->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);

        /*
         * Counting:
         *      4 == "\5" + remote_queue + " " + person
         *      2 * users == " " + user[i] for each user
         *      requests == asprintf results for each request
         *      1 == "\n"
         * Although laborious, doing it this way makes it possible for
         * us to process requests of indeterminate length without
         * applying an arbitrary limit.  Arbitrary Limits Are Bad (tm).
         */
        if (users > 0)
                niov = 4 + 2 * users + requests + 1;
        else
                niov = 4 + requests + 1;
        iov = malloc(niov * sizeof *iov);
        if (iov == NULL)
                fatal(pp, "out of memory in rmremote()");
        iov[0].iov_base = "\5";
        iov[1].iov_base = pp->remote_queue;
        iov[2].iov_base = " ";
        iov[3].iov_base = all ? "-all" : person;
        elem = 4;
        for (i = 0; i < users; i++) {
                iov[elem].iov_base = " ";
                iov[elem + 1].iov_base = user[i];
                elem += 2;
        }
        firstreq = elem;
        for (i = 0; i < requests; i++) {
                asprintf((char **)&iov[elem].iov_base, " %d", requ[i]);
                if (iov[elem].iov_base == 0)
                        fatal(pp, "out of memory in rmremote()");
                elem++;
        }
        iov[elem++].iov_base = "\n";
        for (totlen = i = 0; i < niov; i++)
                totlen += (iov[i].iov_len = strlen(iov[i].iov_base));

        savealrm = signal(SIGALRM, alarmhandler);
        alarm(pp->conn_timeout);
        rem = getport(pp, pp->remote_host, 0);
        (void)signal(SIGALRM, savealrm);
        if (rem < 0) {
                if (from_host != local_host)
                        printf("%s: ", local_host);
                printf("connection to %s is down\n", pp->remote_host);
        } else {
                if (writev(rem, iov, niov) != totlen)
                        fatal(pp, "Lost connection");
                while ((i = read(rem, buf, sizeof(buf))) > 0)
                        (void) fwrite(buf, 1, i, stdout);
                (void) close(rem);
        }
        for (i = 0; i < requests; i++)
                free(iov[firstreq + i].iov_base);
        free(iov);
}

/*
 * 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');
}

void
alarmhandler(int signo __unused)
{
        /* the signal is ignored */
        /* (the '__unused' is just to avoid a compile-time warning) */
}