NetBSD/games/tetris/tetris.c
jsm 5367f3400c Security improvements for games (largely from or inspired by OpenBSD).
Games which run setgid from dm, but don't need to, should drop their
privileges at startup.

Games which have a scorefile should open it at startup, then drop all
privileges leaving just the open writable file descriptor.  If the
game can invoke subprocesses, this should be made close-on-exec.

Games with scorefiles should make sure they do not get a file
descriptor < 3.  (Otherwise, they could get confused and corrupt the
scorefile when using stdin, stdout or stderr.)

Some old setuid revokes from the days of setuid games change into gid
revokes.
1999-09-12 09:02:20 +00:00

333 lines
7.1 KiB
C

/* $NetBSD: tetris.c,v 1.12 1999/09/12 09:02:24 jsm Exp $ */
/*-
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek and Darren F. Provine.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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.
*
* @(#)tetris.c 8.1 (Berkeley) 5/31/93
*/
#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1992, 1993\n\
The Regents of the University of California. All rights reserved.\n");
#endif /* not lint */
/*
* Tetris (or however it is spelled).
*/
#include <sys/time.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "input.h"
#include "scores.h"
#include "screen.h"
#include "tetris.h"
gid_t gid, egid;
static void elide __P((void));
static void setup_board __P((void));
int main __P((int, char **));
void onintr __P((int)) __attribute__((__noreturn__));
void usage __P((void)) __attribute__((__noreturn__));
/*
* Set up the initial board. The bottom display row is completely set,
* along with another (hidden) row underneath that. Also, the left and
* right edges are set.
*/
static void
setup_board()
{
register int i;
register cell *p;
p = board;
for (i = B_SIZE; i; i--)
*p++ = i <= (2 * B_COLS) || (i % B_COLS) < 2;
}
/*
* Elide any full active rows.
*/
static void
elide()
{
register int i, j, base;
register cell *p;
for (i = A_FIRST; i < A_LAST; i++) {
base = i * B_COLS + 1;
p = &board[base];
for (j = B_COLS - 2; *p++ != 0;) {
if (--j <= 0) {
/* this row is to be elided */
memset(&board[base], 0, B_COLS - 2);
scr_update();
tsleep();
while (--base != 0)
board[base + B_COLS] = board[base];
scr_update();
tsleep();
break;
}
}
}
}
int
main(argc, argv)
int argc;
char *argv[];
{
register int pos, c;
register const char *keys;
register int level = 2;
char key_write[6][10];
int ch, i, j;
int fd;
gid = getgid();
egid = getegid();
setegid(gid);
fd = open("/dev/null", O_RDONLY);
if (fd < 3)
exit(1);
close(fd);
keys = "jkl pq";
while ((ch = getopt(argc, argv, "k:l:ps")) != -1)
switch(ch) {
case 'k':
if (strlen(keys = optarg) != 6)
usage();
break;
case 'l':
level = atoi(optarg);
if (level < MINLEVEL || level > MAXLEVEL) {
(void)fprintf(stderr,
"tetris: level must be from %d to %d\n",
MINLEVEL, MAXLEVEL);
exit(1);
}
break;
case 'p':
showpreview = 1;
break;
case 's':
showscores(0);
exit(0);
case '?':
default:
usage();
}
argc -= optind;
argv += optind;
if (argc)
usage();
fallrate = 1000000 / level;
for (i = 0; i <= 5; i++) {
for (j = i+1; j <= 5; j++) {
if (keys[i] == keys[j]) {
(void)fprintf(stderr,
"%s: duplicate command keys specified.\n",
argv[0]);
exit (1);
}
}
if (keys[i] == ' ')
strcpy(key_write[i], "<space>");
else {
key_write[i][0] = keys[i];
key_write[i][1] = '\0';
}
}
sprintf(key_msg,
"%s - left %s - rotate %s - right %s - drop %s - pause %s - quit",
key_write[0], key_write[1], key_write[2], key_write[3],
key_write[4], key_write[5]);
(void)signal(SIGINT, onintr);
scr_init();
setup_board();
srandom(getpid());
scr_set();
pos = A_FIRST*B_COLS + (B_COLS/2)-1;
nextshape = randshape();
curshape = randshape();
scr_msg(key_msg, 1);
for (;;) {
place(curshape, pos, 1);
scr_update();
place(curshape, pos, 0);
c = tgetchar();
if (c < 0) {
/*
* Timeout. Move down if possible.
*/
if (fits_in(curshape, pos + B_COLS)) {
pos += B_COLS;
continue;
}
/*
* Put up the current shape `permanently',
* bump score, and elide any full rows.
*/
place(curshape, pos, 1);
score++;
elide();
/*
* Choose a new shape. If it does not fit,
* the game is over.
*/
curshape = nextshape;
nextshape = randshape();
pos = A_FIRST*B_COLS + (B_COLS/2)-1;
if (!fits_in(curshape, pos))
break;
continue;
}
/*
* Handle command keys.
*/
if (c == keys[5]) {
/* quit */
break;
}
if (c == keys[4]) {
static char msg[] =
"paused - press RETURN to continue";
place(curshape, pos, 1);
do {
scr_update();
scr_msg(key_msg, 0);
scr_msg(msg, 1);
(void) fflush(stdout);
} while (rwait((struct timeval *)NULL) == -1);
scr_msg(msg, 0);
scr_msg(key_msg, 1);
place(curshape, pos, 0);
continue;
}
if (c == keys[0]) {
/* move left */
if (fits_in(curshape, pos - 1))
pos--;
continue;
}
if (c == keys[1]) {
/* turn */
const struct shape *new = &shapes[curshape->rot];
if (fits_in(new, pos))
curshape = new;
continue;
}
if (c == keys[2]) {
/* move right */
if (fits_in(curshape, pos + 1))
pos++;
continue;
}
if (c == keys[3]) {
/* move to bottom */
while (fits_in(curshape, pos + B_COLS)) {
pos += B_COLS;
score++;
}
continue;
}
if (c == '\f') {
scr_clear();
scr_msg(key_msg, 1);
}
}
scr_clear();
scr_end();
(void)printf("Your score: %d point%s x level %d = %d\n",
score, score == 1 ? "" : "s", level, score * level);
savescore(level);
printf("\nHit RETURN to see high scores, ^C to skip.\n");
while ((i = getchar()) != '\n')
if (i == EOF)
break;
showscores(level);
exit(0);
}
void
onintr(signo)
int signo __attribute__((__unused__));
{
scr_clear();
scr_end();
exit(0);
}
void
usage()
{
(void)fprintf(stderr, "usage: tetris [-ps] [-k keys] [-l level]\n");
exit(1);
}