minix/games/adventure/save.c

869 lines
17 KiB
C
Raw Normal View History

/* $NetBSD: save.c,v 1.13 2012/01/08 18:16:00 dholland Exp $ */
/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* The game adventure was originally written in Fortran by Will Crowther
* and Don Woods. It was later translated to C and enhanced by Jim
* Gillogly. This code is derived from software contributed to Berkeley
* by Jim Gillogly at The Rand Corporation.
*
* 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
#if 0
static char sccsid[] = "@(#)save.c 8.1 (Berkeley) 5/31/93";
#else
__RCSID("$NetBSD: save.c,v 1.13 2012/01/08 18:16:00 dholland Exp $");
#endif
#endif /* not lint */
#include <sys/types.h>
#include <sys/time.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <err.h>
#include <assert.h>
#include "hdr.h"
#include "extern.h"
struct savefile {
FILE *f;
const char *name;
bool warned;
unsigned bintextpos;
uint32_t key;
struct crcstate crc;
unsigned char pad[8];
unsigned padpos;
};
#define BINTEXT_WIDTH 60
#define FORMAT_VERSION 2
#define FORMAT_VERSION_NOSUM 1
static const char header[] = "Adventure save file\n";
////////////////////////////////////////////////////////////
// base16 output encoding
/*
* Map 16 plain values into 90 coded values and back.
*/
static const char coding[90] =
"Db.GOyT]7a6zpF(c*5H9oK~0[WVAg&kR)ml,2^q-1Y3v+"
"X/=JirZL$C>_N?:}B{dfnsxU<@MQ%8|P!4h`ESt;euwIj"
;
static int
readletter(char letter, unsigned char *ret)
{
const char *s;
s = strchr(coding, letter);
if (s == NULL) {
return 1;
}
*ret = (s - coding) % 16;
return 0;
}
static char
writeletter(unsigned char nibble)
{
unsigned code;
assert(nibble < 16);
do {
code = (16 * (random() % 6)) + nibble;
} while (code >= 90);
return coding[code];
}
////////////////////////////////////////////////////////////
// savefile
/*
* Open a savefile.
*/
static struct savefile *
savefile_open(const char *name, bool forwrite)
{
struct savefile *sf;
sf = malloc(sizeof(*sf));
if (sf == NULL) {
return NULL;
}
sf->f = fopen(name, forwrite ? "w" : "r");
if (sf->f == NULL) {
free(sf);
fprintf(stderr,
"Hmm. The name \"%s\" appears to be magically blocked.\n",
name);
return NULL;
}
sf->name = name;
sf->warned = false;
sf->bintextpos = 0;
sf->key = 0;
crc_start(&sf->crc);
memset(sf->pad, 0, sizeof(sf->pad));
sf->padpos = 0;
return sf;
}
/*
* Raw read.
*/
static int
savefile_rawread(struct savefile *sf, void *data, size_t len)
{
size_t result;
result = fread(data, 1, len, sf->f);
if (result != len || ferror(sf->f)) {
fprintf(stderr, "Oops: error reading %s.\n", sf->name);
sf->warned = true;
return 1;
}
return 0;
}
/*
* Raw write.
*/
static int
savefile_rawwrite(struct savefile *sf, const void *data, size_t len)
{
size_t result;
result = fwrite(data, 1, len, sf->f);
if (result != len || ferror(sf->f)) {
fprintf(stderr, "Oops: error writing %s.\n", sf->name);
sf->warned = true;
return 1;
}
return 0;
}
/*
* Close a savefile.
*/
static int
savefile_close(struct savefile *sf)
{
int ret;
if (sf->bintextpos > 0) {
savefile_rawwrite(sf, "\n", 1);
}
ret = 0;
if (fclose(sf->f)) {
if (!sf->warned) {
fprintf(stderr, "Oops: error on %s.\n", sf->name);
}
ret = 1;
}
free(sf);
return ret;
}
/*
* Read encoded binary data, discarding any whitespace that appears.
*/
static int
savefile_bintextread(struct savefile *sf, void *data, size_t len)
{
size_t pos;
unsigned char *udata;
int ch;
udata = data;
pos = 0;
while (pos < len) {
ch = fgetc(sf->f);
if (ch == EOF || ferror(sf->f)) {
fprintf(stderr, "Oops: error reading %s.\n", sf->name);
sf->warned = true;
return 1;
}
if (ch == ' ' || ch == '\t' || ch == '\r' || ch == '\n') {
continue;
}
udata[pos++] = ch;
}
return 0;
}
/*
* Read binary data, decoding from text using readletter().
*/
static int
savefile_binread(struct savefile *sf, void *data, size_t len)
{
unsigned char buf[64];
unsigned char *udata;
unsigned char val1, val2;
size_t pos, amt, i;
udata = data;
pos = 0;
while (pos < len) {
amt = len - pos;
if (amt > sizeof(buf) / 2) {
amt = sizeof(buf) / 2;
}
if (savefile_bintextread(sf, buf, amt*2)) {
return 1;
}
for (i=0; i<amt; i++) {
if (readletter(buf[i*2], &val1)) {
return 1;
}
if (readletter(buf[i*2 + 1], &val2)) {
return 1;
}
udata[pos++] = val1 * 16 + val2;
}
}
return 0;
}
/*
* Write encoded binary data, inserting newlines to get a neatly
* formatted block.
*/
static int
savefile_bintextwrite(struct savefile *sf, const void *data, size_t len)
{
size_t pos, amt;
const unsigned char *udata;
udata = data;
pos = 0;
while (pos < len) {
amt = BINTEXT_WIDTH - sf->bintextpos;
if (amt > len - pos) {
amt = len - pos;
}
if (savefile_rawwrite(sf, udata + pos, amt)) {
return 1;
}
pos += amt;
sf->bintextpos += amt;
if (sf->bintextpos >= BINTEXT_WIDTH) {
savefile_rawwrite(sf, "\n", 1);
sf->bintextpos = 0;
}
}
return 0;
}
/*
* Write binary data, encoding as text using writeletter().
*/
static int
savefile_binwrite(struct savefile *sf, const void *data, size_t len)
{
unsigned char buf[64];
const unsigned char *udata;
size_t pos, bpos;
unsigned char byte;
udata = data;
pos = 0;
bpos = 0;
while (pos < len) {
byte = udata[pos++];
buf[bpos++] = writeletter(byte >> 4);
buf[bpos++] = writeletter(byte & 0xf);
if (bpos >= sizeof(buf)) {
if (savefile_bintextwrite(sf, buf, bpos)) {
return 1;
}
bpos = 0;
}
}
if (savefile_bintextwrite(sf, buf, bpos)) {
return 1;
}
return 0;
}
/*
* Lightweight "encryption" for save files. This is not meant to
* be secure and wouldn't be even if we didn't write the decrypt
* key to the beginning of the save file; it's just meant to be
* enough to discourage casual cheating.
*/
/*
* Make cheesy hash of buf[0..buflen]. Note: buf and outhash may overlap.
*/
static void
hash(const void *data, size_t datalen, unsigned char *out, size_t outlen)
{
const unsigned char *udata;
size_t i;
uint64_t val;
const unsigned char *uval;
size_t valpos;
udata = data;
val = 0;
for (i=0; i<datalen; i++) {
val = val ^ 0xbadc0ffee;
val = (val << 4) | (val >> 60);
val += udata[i] ^ 0xbeef;
}
uval = (unsigned char *)&val;
valpos = 0;
for (i=0; i<outlen; i++) {
out[i] = uval[valpos++];
if (valpos >= sizeof(val)) {
valpos = 0;
}
}
}
/*
* Set the "encryption" key.
*/
static void
savefile_key(struct savefile *sf, uint32_t key)
{
sf->key = 0;
crc_start(&sf->crc);
hash(&sf->key, sizeof(sf->key), sf->pad, sizeof(sf->pad));
sf->padpos = 0;
}
/*
* Get an "encryption" pad byte. This forms a stream "cipher" that we
* xor with the plaintext save data.
*/
static unsigned char
savefile_getpad(struct savefile *sf)
{
unsigned char ret;
ret = sf->pad[sf->padpos++];
if (sf->padpos >= sizeof(sf->pad)) {
hash(sf->pad, sizeof(sf->pad), sf->pad, sizeof(sf->pad));
sf->padpos = 0;
}
return ret;
}
/*
* Read "encrypted" data.
*/
static int
savefile_cread(struct savefile *sf, void *data, size_t len)
{
char buf[64];
unsigned char *udata;
size_t pos, amt, i;
unsigned char ch;
udata = data;
pos = 0;
while (pos < len) {
amt = len - pos;
if (amt > sizeof(buf)) {
amt = sizeof(buf);
}
if (savefile_binread(sf, buf, amt)) {
return 1;
}
for (i=0; i<amt; i++) {
ch = buf[i];
ch ^= savefile_getpad(sf);
udata[pos + i] = ch;
}
pos += amt;
}
crc_add(&sf->crc, data, len);
return 0;
}
/*
* Write "encrypted" data.
*/
static int
savefile_cwrite(struct savefile *sf, const void *data, size_t len)
{
char buf[64];
const unsigned char *udata;
size_t pos, amt, i;
unsigned char ch;
udata = data;
pos = 0;
while (pos < len) {
amt = len - pos;
if (amt > sizeof(buf)) {
amt = sizeof(buf);
}
for (i=0; i<amt; i++) {
ch = udata[pos + i];
ch ^= savefile_getpad(sf);
buf[i] = ch;
}
if (savefile_binwrite(sf, buf, amt)) {
return 1;
}
pos += amt;
}
crc_add(&sf->crc, data, len);
return 0;
}
////////////////////////////////////////////////////////////
// compat for old save files
struct compat_saveinfo {
void *address;
int width;
};
static const struct compat_saveinfo compat_savearray[] =
{
{&abbnum, sizeof(abbnum)},
{&attack, sizeof(attack)},
{&blklin, sizeof(blklin)},
{&bonus, sizeof(bonus)},
{&chloc, sizeof(chloc)},
{&chloc2, sizeof(chloc2)},
{&clock1, sizeof(clock1)},
{&clock2, sizeof(clock2)},
{&closed, sizeof(closed)},
{&isclosing, sizeof(isclosing)},
{&daltloc, sizeof(daltloc)},
{&demo, sizeof(demo)},
{&detail, sizeof(detail)},
{&dflag, sizeof(dflag)},
{&dkill, sizeof(dkill)},
{&dtotal, sizeof(dtotal)},
{&foobar, sizeof(foobar)},
{&gaveup, sizeof(gaveup)},
{&holding, sizeof(holding)},
{&iwest, sizeof(iwest)},
{&k, sizeof(k)},
{&k2, sizeof(k2)},
{&knfloc, sizeof(knfloc)},
{&kq, sizeof(kq)},
{&latency, sizeof(latency)},
{&limit, sizeof(limit)},
{&lmwarn, sizeof(lmwarn)},
{&loc, sizeof(loc)},
{&maxdie, sizeof(maxdie)},
{&maxscore, sizeof(maxscore)},
{&newloc, sizeof(newloc)},
{&numdie, sizeof(numdie)},
{&obj, sizeof(obj)},
{&oldloc2, sizeof(oldloc2)},
{&oldloc, sizeof(oldloc)},
{&panic, sizeof(panic)},
{&saveday, sizeof(saveday)},
{&savet, sizeof(savet)},
{&scoring, sizeof(scoring)},
{&spk, sizeof(spk)},
{&stick, sizeof(stick)},
{&tally, sizeof(tally)},
{&tally2, sizeof(tally2)},
{&tkk, sizeof(tkk)},
{&turns, sizeof(turns)},
{&verb, sizeof(verb)},
{&wd1, sizeof(wd1)},
{&wd2, sizeof(wd2)},
{&wasdark, sizeof(wasdark)},
{&yea, sizeof(yea)},
{atloc, sizeof(atloc)},
{dloc, sizeof(dloc)},
{dseen, sizeof(dseen)},
{fixed, sizeof(fixed)},
{hinted, sizeof(hinted)},
{links, sizeof(links)},
{odloc, sizeof(odloc)},
{place, sizeof(place)},
{prop, sizeof(prop)},
{tk, sizeof(tk)},
{NULL, 0}
};
static int
compat_restore(const char *infile)
{
FILE *in;
const struct compat_saveinfo *p;
char *s;
long sum, cksum = 0;
int i;
struct crcstate crc;
if ((in = fopen(infile, "rb")) == NULL) {
fprintf(stderr,
"Hmm. The file \"%s\" appears to be magically blocked.\n",
infile);
return 1;
}
fread(&sum, sizeof(sum), 1, in); /* Get the seed */
srandom((int) sum);
for (p = compat_savearray; p->address != NULL; p++) {
fread(p->address, p->width, 1, in);
for (s = p->address, i = 0; i < p->width; i++, s++)
*s = (*s ^ random()) & 0xFF; /* Lightly decrypt */
}
fclose(in);
crc_start(&crc); /* See if she cheated */
for (p = compat_savearray; p->address != NULL; p++)
crc_add(&crc, p->address, p->width);
cksum = crc_get(&crc);
if (sum != cksum) /* Tsk tsk */
return 2; /* Altered the file */
/* We successfully restored, so this really was a save file */
/*
* The above code loads these from disk even though they're
* pointers. Null them out and hope we don't crash on them
* later; that's better than having them be garbage.
*/
tkk = NULL;
wd1 = NULL;
wd2 = NULL;
return 0;
}
////////////////////////////////////////////////////////////
// save + restore
static int *const save_ints[] = {
&abbnum,
&attack,
&blklin,
&bonus,
&chloc,
&chloc2,
&clock1,
&clock2,
&closed,
&isclosing,
&daltloc,
&demo,
&detail,
&dflag,
&dkill,
&dtotal,
&foobar,
&gaveup,
&holding,
&iwest,
&k,
&k2,
&knfloc,
&kq,
&latency,
&limit,
&lmwarn,
&loc,
&maxdie,
&maxscore,
&newloc,
&numdie,
&obj,
&oldloc2,
&oldloc,
&panic,
&saveday,
&savet,
&scoring,
&spk,
&stick,
&tally,
&tally2,
&turns,
&verb,
&wasdark,
&yea,
};
static const unsigned num_save_ints = __arraycount(save_ints);
#define INTARRAY(sym) { sym, __arraycount(sym) }
static const struct {
int *ptr;
unsigned num;
} save_intarrays[] = {
INTARRAY(atloc),
INTARRAY(dseen),
INTARRAY(dloc),
INTARRAY(odloc),
INTARRAY(fixed),
INTARRAY(hinted),
INTARRAY(links),
INTARRAY(place),
INTARRAY(prop),
INTARRAY(tk),
};
static const unsigned num_save_intarrays = __arraycount(save_intarrays);
#undef INTARRAY
#if 0
static const struct {
void *ptr;
size_t len;
} save_blobs[] = {
{ &wd1, sizeof(wd1) },
{ &wd2, sizeof(wd2) },
{ &tkk, sizeof(tkk) },
};
static const unsigned num_save_blobs = __arraycount(save_blobs);
#endif
/*
* Write out a save file. Returns nonzero on error.
*/
int
save(const char *outfile)
{
struct savefile *sf;
struct timespec now;
uint32_t key, writeable_key;
uint32_t version;
unsigned i, j, n;
uint32_t val, sum;
sf = savefile_open(outfile, true);
if (sf == NULL) {
return 1;
}
if (savefile_rawwrite(sf, header, strlen(header))) {
savefile_close(sf);
return 1;
}
version = htonl(FORMAT_VERSION);
if (savefile_binwrite(sf, &version, sizeof(version))) {
savefile_close(sf);
return 1;
}
clock_gettime(CLOCK_REALTIME, &now);
key = (uint32_t)(now.tv_sec & 0xffffffff) ^ (uint32_t)(now.tv_nsec);
writeable_key = htonl(key);
if (savefile_binwrite(sf, &writeable_key, sizeof(writeable_key))) {
savefile_close(sf);
return 1;
}
/* other parts of the code may depend on us doing this here */
srandom(key);
savefile_key(sf, key);
/*
* Integers
*/
for (i=0; i<num_save_ints; i++) {
val = *(save_ints[i]);
val = htonl(val);
if (savefile_cwrite(sf, &val, sizeof(val))) {
savefile_close(sf);
return 1;
}
}
/*
* Arrays of integers
*/
for (i=0; i<num_save_intarrays; i++) {
n = save_intarrays[i].num;
for (j=0; j<n; j++) {
val = save_intarrays[i].ptr[j];
val = htonl(val);
if (savefile_cwrite(sf, &val, sizeof(val))) {
savefile_close(sf);
return 1;
}
}
}
#if 0
/*
* Blobs
*/
for (i=0; i<num_save_blobs; i++) {
if (savefile_cwrite(sf, save_blobs[i].ptr, save_blobs[i].len)) {
savefile_close(sf);
return 1;
}
}
#endif
sum = htonl(crc_get(&sf->crc));
if (savefile_binwrite(sf, &sum, sizeof(&sum))) {
savefile_close(sf);
return 1;
}
savefile_close(sf);
return 0;
}
/*
* Read in a save file. Returns nonzero on error.
*/
int
restore(const char *infile)
{
struct savefile *sf;
char buf[sizeof(header)];
size_t headersize = strlen(header);
uint32_t version, key, sum;
unsigned i, j, n;
uint32_t val;
bool skipsum = false;
sf = savefile_open(infile, false);
if (sf == NULL) {
return 1;
}
if (savefile_rawread(sf, buf, headersize)) {
savefile_close(sf);
return 1;
}
buf[headersize] = 0;
if (strcmp(buf, header) != 0) {
savefile_close(sf);
fprintf(stderr, "Oh dear, that isn't one of my save files.\n");
fprintf(stderr,
"Trying the Olde Waye; this myte notte Worke.\n");
return compat_restore(infile);
}
if (savefile_binread(sf, &version, sizeof(version))) {
savefile_close(sf);
return 1;
}
version = ntohl(version);
switch (version) {
case FORMAT_VERSION:
break;
case FORMAT_VERSION_NOSUM:
skipsum = true;
break;
default:
savefile_close(sf);
fprintf(stderr,
"Oh dear, that file must be from the future. I don't know"
" how to read it!\n");
return 1;
}
if (savefile_binread(sf, &key, sizeof(key))) {
savefile_close(sf);
return 1;
}
key = ntohl(key);
savefile_key(sf, key);
/* other parts of the code may depend on us doing this here */
srandom(key);
/*
* Integers
*/
for (i=0; i<num_save_ints; i++) {
if (savefile_cread(sf, &val, sizeof(val))) {
savefile_close(sf);
return 1;
}
val = ntohl(val);
*(save_ints[i]) = val;
}
/*
* Arrays of integers
*/
for (i=0; i<num_save_intarrays; i++) {
n = save_intarrays[i].num;
for (j=0; j<n; j++) {
if (savefile_cread(sf, &val, sizeof(val))) {
savefile_close(sf);
return 1;
}
val = ntohl(val);
save_intarrays[i].ptr[j] = val;
}
}
#if 0
/*
* Blobs
*/
for (i=0; i<num_save_blobs; i++) {
if (savefile_cread(sf, save_blobs[i].ptr, save_blobs[i].len)) {
savefile_close(sf);
return 1;
}
}
#endif
if (savefile_binread(sf, &sum, sizeof(&sum))) {
savefile_close(sf);
return 1;
}
sum = ntohl(sum);
/* See if she cheated */
if (!skipsum && sum != crc_get(&sf->crc)) {
/* Tsk tsk, altered the file */
savefile_close(sf);
return 2;
}
savefile_close(sf);
/* Load theoretically invalidates these */
tkk = NULL;
wd1 = NULL;
wd2 = NULL;
return 0;
}