view rogue4/xstr.c @ 176:db1c9a21a7c3

srogue: prevent overflowing the score file name. If SCOREFILE is not defined, roguehome() is called to find a directory for the score file. It copies up to PATH_MAX-20 bytes from an environment variable to a static buffer. Later these are strcpy()'d to scorefile, which is of size LINLEN. Unfortunately LINLEN is 80 and PATH_MAX is at least 256. On Linux, it happens to be 4096. I haven't yet managed to crash or exploit it, but there are surely no beneficial consequences, so roguehome() has been modified to check the length, and the string it returns is also checked in main().
author John "Elwin" Edwards
date Sun, 02 Aug 2015 12:14:47 -0400
parents 9535a08ddc39
children
line wrap: on
line source

/*
 *
 * Rogue: Exploring the Dungeons of Doom
 * Copyright (C) 1980, 1981, 1982 Michael Toy, Ken Arnold and Glenn Wichman
 * All rights reserved.
 *
 * See the file LICENSE.TXT for full copyright and licensing information.
 */

static char *sccsid = "@(#)xstr.c	4.1 (Berkeley) 10/1/80";
#include <stdio.h>
#include <ctype.h>
#include <sys/types.h>
#include <signal.h>

/*
 * xstr - extract and hash strings in a C program
 *
 * Bill Joy UCB
 * November, 1978
 */

#define	ignore(a)	(a)

char	*calloc();
off_t	tellpt;
off_t	hashit();
char	*mktemp();
void	onintr(int);
char	*savestr();
char	*strcat();
char	*strcpy();
off_t	yankstr();

off_t	mesgpt;
char	*strings =	"strings";

int	cflg;
int	vflg;
int	readstd;

main(argc, argv)
	int argc;
	char *argv[];
{

	argc--, argv++;
	while (argc > 0 && argv[0][0] == '-') {
		register char *cp = &(*argv++)[1];

		argc--;
		if (*cp == 0) {
			readstd++;
			continue;
		}
		do switch (*cp++) {

		case 'c':
			cflg++;
			continue;

		case 'v':
			vflg++;
			continue;

		default:
			fprintf(stderr, "usage: xstr [ -v ] [ -c ] [ - ] [ name ... ]\n");
		} while (*cp);
	}
	if (signal(SIGINT, SIG_IGN) == SIG_DFL)
		signal(SIGINT, onintr);
	if (cflg || argc == 0 && !readstd)
		inithash();
	else
		strings = mktemp(savestr("/tmp/xstrXXXXXX"));
	while (readstd || argc > 0) {
		if (freopen("x.c", "w", stdout) == NULL)
			perror("x.c"), exit(1);
		if (!readstd && freopen(argv[0], "r", stdin) == NULL)
			perror(argv[0]), exit(2);
		process("x.c");
		if (readstd == 0)
			argc--, argv++;
		else
			readstd = 0;
	};
	flushsh();
	if (cflg == 0)
		xsdotc();
	if (strings[0] == '/')
		ignore(md_unlink(strings));
	exit(0);
}

process(name)
	char *name;
{
	char *cp;
	char linebuf[BUFSIZ];
	register int c;
	register int incomm = 0;

	printf("extern char\txstr[];\n");
	for (;;) {
		if (fgets(linebuf, sizeof linebuf, stdin) == NULL) {
			if (ferror(stdin)) {
				perror(name);
				exit(3);
			}
			break;
		}
		if (linebuf[0] == '#') {
			if (linebuf[1] == ' ' && isdigit(linebuf[2]))
				printf("#line%s", &linebuf[1]);
			else
				printf("%s", linebuf);
			continue;
		}
		for (cp = linebuf; c = *cp++;) switch (c) {
			
		case '"':
			if (incomm)
				goto def;
			printf("(&xstr[%d])", (int) yankstr(&cp));
			break;

		case '\'':
			if (incomm)
				goto def;
			putchar(c);
			if (*cp)
				putchar(*cp++);
			break;

		case '/':
			if (incomm || *cp != '*')
				goto def;
			incomm = 1;
			cp++;
			printf("/*");
			continue;

		case '*':
			if (incomm && *cp == '/') {
				incomm = 0;
				cp++;
				printf("*/");
				continue;
			}
			goto def;
		
def:
		default:
			putchar(c);
			break;
		}
	}
	if (ferror(stdout))
		perror("x.c"), onintr(-1);
}

off_t
yankstr(cpp)
	register char **cpp;
{
	register char *cp = *cpp;
	register int c, ch;
	char dbuf[BUFSIZ];
	register char *dp = dbuf;
	register char *tp;

	while (c = *cp++) {
		switch (c) {

		case '"':
			cp++;
			goto out;

		case '\\':
			c = *cp++;
			if (c == 0)
				break;
			if (c == '\n')
				continue;
			for (tp = "b\bt\tr\rn\nf\f\\\\\"\""; ch = *tp++; tp++)
				if (c == ch) {
					c = *tp;
					goto gotc;
				}
			if (!octdigit(c)) {
				*dp++ = '\\';
				break;
			}
			c -= '0';
			if (!octdigit(*cp))
				break;
			c <<= 3, c += *cp++ - '0';
			if (!octdigit(*cp))
				break;
			c <<= 3, c += *cp++ - '0';
			break;
		}
gotc:
		*dp++ = c;
	}
out:
	*cpp = --cp;
	*dp = 0;
	return (hashit(dbuf, 1));
}

octdigit(c)
	char c;
{

	return (isdigit(c) && c != '8' && c != '9');
}

inithash()
{
	char buf[BUFSIZ];
	register FILE *mesgread = fopen(strings, "r");

	if (mesgread == NULL)
		return;
	for (;;) {
		mesgpt = tellpt;
		if (fgetNUL(buf, sizeof buf, mesgread) == 0)
			break;
		hashit(buf, 0);
	}
	ignore(fclose(mesgread));
}

fgetNUL(obuf, rmdr, file)
	char *obuf;
	register int rmdr;
	FILE *file;
{
	register c;
	register char *buf = obuf;

	while (--rmdr > 0 && (c = xgetc(file)) != 0 && c != EOF)
		*buf++ = c;
	*buf++ = 0;
	return ((feof(file) || ferror(file)) ? 0 : 1);
}

xgetc(file)
	FILE *file;
{

	tellpt++;
	return (getc(file));
}

#define	BUCKETS	128

struct	hash {
	off_t	hpt;
	char	*hstr;
	struct	hash *hnext;
	short	hnew;
} bucket[BUCKETS];

off_t
hashit(str, new)
	char *str;
	int new;
{
	int i;
	register struct hash *hp, *hp0;

	hp = hp0 = &bucket[lastchr(str) & 0177];
	while (hp->hnext) {
		hp = hp->hnext;
		i = istail(str, hp->hstr);
		if (i >= 0)
			return (hp->hpt + i);
	}
	hp = (struct hash *) calloc(1, sizeof (*hp));
	hp->hpt = mesgpt;
	hp->hstr = savestr(str);
	mesgpt += strlen(hp->hstr) + 1;
	hp->hnext = hp0->hnext;
	hp->hnew = new;
	hp0->hnext = hp;
	return (hp->hpt);
}

flushsh()
{
	register int i;
	register struct hash *hp;
	register FILE *mesgwrit;
	register int old = 0, new = 0;

	for (i = 0; i < BUCKETS; i++)
		for (hp = bucket[i].hnext; hp != NULL; hp = hp->hnext)
			if (hp->hnew)
				new++;
			else
				old++;
	if (new == 0 && old != 0)
		return;
	mesgwrit = fopen(strings, old ? "a" : "w");
	for (i = 0; i < BUCKETS; i++)
		for (hp = bucket[i].hnext; hp != NULL; hp = hp->hnext) {
			found(hp->hnew, hp->hpt, hp->hstr);
			if (hp->hnew) {
				fseek(mesgwrit, hp->hpt, 0);
				ignore(fwrite(hp->hstr, strlen(hp->hstr) + 1, 1, mesgwrit));
				if (ferror(mesgwrit))
					perror(strings), exit(4);
			}
		}
	ignore(fclose(mesgwrit));
}

found(new, off, str)
	int new;
	off_t off;
	char *str;
{
	if (vflg == 0)
		return;
	if (!new)
		fprintf(stderr, "found at %d:", (int) off);
	else
		fprintf(stderr, "new at %d:", (int) off);
	prstr(str);
	fprintf(stderr, "\n");
}

prstr(cp)
	register char *cp;
{
	register int c;

	while (c = (*cp++ & 0377))
		if (c < ' ')
			fprintf(stderr, "^%c", c + '`');
		else if (c == 0177)
			fprintf(stderr, "^?");
		else if (c > 0200)
			fprintf(stderr, "\\%03o", c);
		else
			fprintf(stderr, "%c", c);
}

xsdotc()
{
	register FILE *strf = fopen(strings, "r");
	register FILE *xdotcf;

	if (strf == NULL)
		perror(strings), exit(5);
	xdotcf = fopen("xs.c", "w");
	if (xdotcf == NULL)
		perror("xs.c"), exit(6);
	fprintf(xdotcf, "char\txstr[] = {\n");
	for (;;) {
		register int i, c;

		for (i = 0; i < 20; i++) {
			c = getc(strf);
			if (ferror(strf)) {
				perror(strings);
				onintr(-1);
			}
			if (feof(strf)) {
				fprintf(xdotcf, "\n");
				goto out;
			}
			fprintf(xdotcf, "%d,", c);
		}
		fprintf(xdotcf, "\n");
	}
out:
	fprintf(xdotcf, "};\n");
	ignore(fclose(xdotcf));
	ignore(fclose(strf));
}

char *
savestr(cp)
	register char *cp;
{
	register char *dp = (char *) calloc(1, strlen(cp) + 1);

	return (strcpy(dp, cp));
}

Ignore(void *a)
{

	a = a;
}

ignorf(a)
void (*a)();
{

	a = a;
}

lastchr(cp)
	register char *cp;
{

	while (cp[0] && cp[1])
		cp++;
	return (*cp);
}

istail(str, of)
	register char *str, *of;
{
	register int d = strlen(of) - strlen(str);

	if (d < 0 || strcmp(&of[d], str) != 0)
		return (-1);
	return (d);
}

void
onintr(int sig)
{

	ignorf(signal(SIGINT, SIG_IGN));
	if (strings[0] == '/')
		ignore(md_unlink(strings));
	ignore(md_unlink("x.c"));
	ignore(md_unlink("xs.c"));
	exit(7);
}