/*      $NetBSD: timedc.c,v 1.22 2012/01/16 17:38:16 christos Exp $     */

/*-
 * Copyright (c) 1985, 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) 1985, 1993\
 The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)timedc.c    8.1 (Berkeley) 6/6/93";
#else
__RCSID("$NetBSD: timedc.c,v 1.22 2012/01/16 17:38:16 christos Exp $");
#endif
#endif /* not lint */

#include "timedc.h"
#include <ctype.h>
#include <setjmp.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <fcntl.h>
#include <pwd.h>
#include <err.h>

int trace = 0;
FILE *fd = 0;
int     margc;
int     fromatty;
#define MAX_MARGV       20
char    *margv[MAX_MARGV];
char    cmdline[200];
jmp_buf toplevel;
static const struct cmd *getcmd(char *);
static int drop_privileges(void);

int
main(int argc, char *argv[])
{
        const struct cmd *c;

        fcntl(3, F_CLOSEM);
        openlog("timedc", 0, LOG_AUTH);

        /*
         * security dictates!
         */
        if (priv_resources() < 0)
                errx(EXIT_FAILURE, "Could not get privileged resources");
        if (drop_privileges() < 0)
                errx(EXIT_FAILURE, "Could not drop privileges");

        if (--argc > 0) {
                c = getcmd(*++argv);
                if (c == (struct cmd *)-1) {
                        printf("?Ambiguous command\n");
                        exit(EXIT_FAILURE);
                }
                if (c == 0) {
                        printf("?Invalid command\n");
                        exit(EXIT_FAILURE);
                }
                (*c->c_handler)(argc, argv);
                exit(EXIT_SUCCESS);
        }

        fromatty = isatty(fileno(stdin));
        if (setjmp(toplevel))
                putchar('\n');
        (void) signal(SIGINT, intr);
        for (;;) {
                if (fromatty) {
                        printf("timedc> ");
                        (void) fflush(stdout);
                }
                if (fgets(cmdline, sizeof(cmdline), stdin) == NULL)
                        quit(0, NULL);
                if (cmdline[0] == 0)
                        break;
                if (makeargv()) {
                        printf("?Too many arguments\n");
                        continue;
                }
                if (margv[0] == 0)
                        continue;
                c = getcmd(margv[0]);
                if (c == (struct cmd *)-1) {
                        printf("?Ambiguous command\n");
                        continue;
                }
                if (c == 0) {
                        printf("?Invalid command\n");
                        continue;
                }
                (*c->c_handler)(margc, margv);
        }
        return 0;
}

void
intr(int signo)
{
        (void) signo;
        if (!fromatty)
                exit(EXIT_SUCCESS);
        longjmp(toplevel, 1);
}


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

        longest = 0;
        nmatches = 0;
        found = 0;
        for (c = cmdtab; c < &cmdtab[NCMDS]; c++) {
                p = c->c_name;
                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.
 */
int
makeargv(void)
{
        char *cp;
        char **argp = margv;

        margc = 0;
        for (cp = cmdline; argp < &margv[MAX_MARGV - 1] && *cp;) {
                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';
        }
        if (margc == MAX_MARGV - 1)
                return 1;
        *argp++ = 0;
        return 0;
}

#define HELPINDENT (sizeof ("directory"))

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

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

                printf("Commands may be abbreviated.  Commands are:\n\n");
                for (c = cmdtab; c < &cmdtab[NCMDS]; c++) {
                        int 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]) {
                                        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);
        }
}

static int
drop_privileges(void)
{
        static const char user[] = "_timedc";
        const struct passwd *pw;
        uid_t uid;
        gid_t gid;

        if ((pw = getpwnam(user)) == NULL) {
                warnx("getpwnam(\"%s\") failed", user);
                return -1;
        }
        uid = pw->pw_uid;
        gid = pw->pw_gid;
        if (setgroups(1, &gid)) {
                warn("setgroups");
                return -1;
        }
        if (setgid(gid)) {
                warn("setgid");
                return -1;
        }
        if (setuid(uid)) {
                warn("setuid");
                return -1;
        }
        return 0;
}