/*      $NetBSD: lpc.c,v 1.27 2017/05/04 16:26:09 sevan 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
__COPYRIGHT("@(#) Copyright (c) 1983, 1993\
 The Regents of the University of California.  All rights reserved.");
#if 0
static char sccsid[] = "@(#)lpc.c       8.3 (Berkeley) 4/28/95";
#else
__RCSID("$NetBSD: lpc.c,v 1.27 2017/05/04 16:26:09 sevan Exp $");
#endif
#endif /* not lint */

#include <sys/param.h>

#include <dirent.h>
#include <signal.h>
#include <setjmp.h>
#include <syslog.h>
#include <histedit.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <grp.h>
#include <err.h>
#include "lp.h"
#include "lpc.h"
#include "extern.h"

#ifndef LPR_OPER
#define LPR_OPER        "operator"      /* group name of lpr operators */
#endif

/*
 * lpc -- line printer control program
 */

#define MAX_MARGV       20
int     fromatty;

char    *cmdline;
int     margc;
char    *margv[MAX_MARGV];
int     top;
uid_t   uid, euid;

jmp_buf toplevel;

History *hist;
HistEvent he;
EditLine *elptr;

__dead static void       cmdscanner(int);
static struct cmd       *getcmd(const char *);
__dead static void       intr(int);
static void              makeargv(void);
static int               ingroup(const char *);
const char              *prompt(void);
static int               parse(char *, char *p[], int);

int
main(int argc, char *argv[])
{
        euid = geteuid();
        uid = getuid();
        seteuid(uid);
        setprogname(argv[0]);
        openlog("lpd", 0, LOG_LPR);

        if (--argc > 0) {
                argv++;
                exit(!parse(*argv, argv, argc));
        }
        fromatty = isatty(fileno(stdin));
        top = setjmp(toplevel) == 0;
        if (top)
                signal(SIGINT, intr);
        for (;;) {
                cmdscanner(top);
                top = 1;
        }
}

static int
parse(char *arg, char **pargv, int pargc)
{
        struct cmd *c;

        c = getcmd(arg);
        if (c == (struct cmd *)-1) {
                printf("?Ambiguous command\n");
                return(0);
        }
        if (c == 0) {
                printf("?Invalid command\n");
                return(0);
        }
        if (c->c_priv && getuid() && ingroup(LPR_OPER) == 0) {
                printf("?Privileged command\n");
                return(0);
        }
        (*c->c_handler)(pargc, pargv);
        return(1);
}

static void
intr(int signo)
{
        el_end(elptr);
        history_end(hist);
        if (!fromatty)
                exit(0);
        longjmp(toplevel, 1);
}

const char *
prompt(void)
{
        return ("lpc> ");
}

/*
 * Command parser.
 */
static void
cmdscanner(int tp)
{
        int scratch;
        const char *elline;

        if (!tp)
                putchar('\n');
        hist = history_init();
        history(hist, &he, H_SETSIZE, 100);     /* 100 elt history buffer */

        elptr = el_init(getprogname(), stdin, stdout, stderr);
        el_set(elptr, EL_EDITOR, "emacs");
        el_set(elptr, EL_PROMPT, prompt);
        el_set(elptr, EL_HIST, history, hist);
        el_source(elptr, NULL);

        for (;;) {
                cmdline = NULL;
                do {
                        if (((elline = el_gets(elptr, &scratch)) != NULL)
                            && (scratch != 0)) {
                                history(hist, &he, H_ENTER, elline);
                                cmdline = strdup(elline);
                                makeargv();
                        } else {
                                margc = 0;
                                break;
                        }
                } while (margc == 0);
                if (margc == 0)
                        quit(0, NULL);
                if (!parse(cmdline, margv, margc)) {
                        if (cmdline != NULL)
                                free(cmdline);
                        continue;
                }
                fflush(stdout);
                if (cmdline != NULL)
                        free(cmdline);
        }
        longjmp(toplevel, 0);
}

static struct cmd *
getcmd(const char *name)
{
        const char *p, *q;
        struct cmd *c, *found;
        int nmatches, longest;

        longest = 0;
        nmatches = 0;
        found = 0;
        for (c = cmdtab; (p = c->c_name) != NULL; c++) {
                for (q = name; *q == *p++; q++)
                        if (*q == 0)            /* exact match? */
                                return(c);
                if (!*q) {                      /* the name was a prefix */
                        if (q - name > longest) {
                                longest = q - name;
                                nmatches = 1;
                                found = c;
                        } else if (q - name == longest)
                                nmatches++;
                }
        }
        if (nmatches > 1)
                return((struct cmd *)-1);
        return(found);
}

/*
 * Slice a string up into argc/argv.
 */
static void
makeargv(void)
{
        char *cp;
        char **argp = margv;
        int n = 0;
        size_t s;

        s = strlen(cmdline) + 1;
        margc = 0;
        for (cp = cmdline; *cp && (size_t)(cp - cmdline) < s && n < MAX_MARGV; n++) {
                while (isspace((unsigned char)*cp))
                        cp++;
                if (*cp == '\0')
                        break;
                *argp++ = cp;
                margc += 1;
                while (*cp != '\0' && !isspace((unsigned char)*cp))
                        cp++;
                if (*cp == '\0')
                        break;
                *cp++ = '\0';
        }
        *argp++ = 0;
}

#define HELPINDENT (sizeof ("directory"))

/*
 * Help command.
 */
void
help(int argc, char *argv[])
{
        struct cmd *c;

        if (argc == 1) {
                size_t i, j, w;
                size_t columns, width = 0, lines;

                printf("Commands may be abbreviated.  Commands are:\n\n");
                for (c = cmdtab; c->c_name; c++) {
                        size_t len = strlen(c->c_name);

                        if (len > width)
                                width = len;
                }
                width = (width + 8) &~ 7;
                columns = 80 / width;
                if (columns == 0)
                        columns = 1;
                lines = (NCMDS + columns - 1) / columns;
                for (i = 0; i < lines; i++) {
                        for (j = 0; j < columns; j++) {
                                c = cmdtab + j * lines + i;
                                printf("%s", c->c_name);
                                if (c + lines >= &cmdtab[NCMDS - 1]) {
                                        printf("\n");
                                        break;
                                }
                                w = strlen(c->c_name);
                                while (w < width) {
                                        w = (w + 8) &~ 7;
                                        putchar('\t');
                                }
                        }
                }
                return;
        }
        while (--argc > 0) {
                char *arg;
                arg = *++argv;
                c = getcmd(arg);
                if (c == (struct cmd *)-1)
                        printf("?Ambiguous help command %s\n", arg);
                else if (c == (struct cmd *)0)
                        printf("?Invalid help command %s\n", arg);
                else
                        printf("%-*s\t%s\n", (int)HELPINDENT,
                                c->c_name, c->c_help);
        }
}

/*
 * return non-zero if the user is a member of the given group
 */
static int
ingroup(const char *grname)
{
        static struct group *gptr = NULL;
        static gid_t groups[NGROUPS];
        static int ngroups;
        gid_t gid;
        int i;

        if (gptr == NULL) {
                if ((gptr = getgrnam(grname)) == NULL) {
                        warnx("Warning: unknown group `%s'",
                                grname);
                        return(0);
                }
                ngroups = getgroups(NGROUPS, groups);
                if (ngroups < 0)
                        err(1, "getgroups");
        }
        gid = gptr->gr_gid;
        for (i = 0; i < ngroups; i++)
                if (gid == groups[i])
                        return(1);
        return(0);
}