view arogue5/save.c @ 110:5f51f7d9805f

arogue5: fix some save/restore-related crashes. The save/restore code took the pointer intended as an argument for the doctor() daemon and wrote it to the savefile as an int. I don't know why it took so long to fail horribly. The problem has been avoided by replacing the value with &player when restoring. That seems to be the only argument ever actually used. The code also writes only four bytes for an unsigned long; if sizeof(long) == 8, it casts to unsigned int first. It failed to do the cast when reading back, with the result that four bytes were read and the other half of the number was effectively uninitialized. It apparently works now, but the save/restore code ought still to be regarded as decidedly unfortunate.
author John "Elwin" Edwards
date Mon, 06 Jan 2014 15:57:17 -0500
parents d852b8f088c5
children 7795b0938921
line wrap: on
line source

/*
 * save and restore routines
 *
 * Advanced Rogue
 * Copyright (C) 1984, 1985 Michael Morgan, Ken Dalka and AT&T
 * All rights reserved.
 *
 * Based on "Rogue: Exploring the Dungeons of Doom"
 * Copyright (C) 1980, 1981 Michael Toy, Ken Arnold and Glenn Wichman
 * All rights reserved.
 *
 * See the file LICENSE.TXT for full copyright and licensing information.
 */

#include "curses.h"
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <signal.h>
#include "rogue.h"

typedef struct stat STAT;

extern char version[], encstr[];
/* extern bool _endwin; */

STAT sbuf;

bool
save_game()
{
    register FILE *savef;
    register int c;
    char buf[LINELEN];

    /*
     * get file name
     */
    mpos = 0;
    if (file_name[0] != '\0')
    {
        if (use_savedir)
	    msg("Save game? ");
        else
	    msg("Save file (%s)? ", file_name);
	do
	{
	    c = readchar();
	    if (c == ESCAPE) return(0);
	} while (c != 'n' && c != 'N' && c != 'y' && c != 'Y');
	mpos = 0;
	if (c == 'y' || c == 'Y')
	{
	    msg("File name: %s", file_name);
	    goto gotfile;
	}
        if (use_savedir) {
            msg("");
	    return FALSE;
        }
    }

    do
    {
	msg("File name: ");
	mpos = 0;
	buf[0] = '\0';
	if (get_str(buf, msgw) == QUIT)
	{
	    msg("");
	    return FALSE;
	}
        msg("");
	strcpy(file_name, buf);
gotfile:
	if ((savef = fopen(file_name, "w")) == NULL)
        {
	    msg(strerror(errno));	/* fake perror() */
            if (use_savedir)
	        return FALSE;
        }
    } while (savef == NULL);

    /*
     * write out encrpyted file (after a stat)
     * The fwrite is to force allocation of the buffer before the write
     */
    if (save_file(savef) != 0) {
	msg("Cannot create save file.");
	unlink(file_name);
	return(FALSE);
    }
    else return(TRUE);
}

/*
 * automatically save a file.  This is used if a HUP signal is
 * recieved
 */
void
auto_save(int sig)
{
    register FILE *savef;
    register int i;

    NOOP(sig);

    for (i = 0; i < NSIG; i++)
	signal(i, SIG_IGN);
    if (file_name[0] != '\0'	&& 
	pstats.s_hpt > 0	&&
	(savef = fopen(file_name, "w")) != NULL)
	save_file(savef);
    exit(1);
}

/*
 * write the saved game on the file
 */
bool
save_file(savef)
register FILE *savef;
{
    int ret;
    int slines = LINES;
    int scols  = COLS;

    wmove(cw, LINES-1, 0);
    draw(cw);
    fwrite("junk", 1, 5, savef);
    fseek(savef, 0L, 0);
    /* _endwin = TRUE; */
    fstat(fileno(savef), &sbuf);

    encwrite(version,strlen(version)+1,savef);
    sprintf(prbuf,"%d x %d\n", LINES, COLS);
    encwrite(prbuf,80,savef);

    msg("");
    ret = rs_save_file(savef);

    fclose(savef);
 
    return(ret);
}

restore(file, envp)
register char *file;
char **envp;
{
    register int inf;
#ifndef _AIX
    extern char **environ;
#endif
    char buf[LINELEN];
    STAT sbuf2;
    int oldcol, oldline;	/* Old number of columns and lines */

    if (strcmp(file, "-r") == 0)
	file = file_name;

    if ((inf = open(file, O_RDONLY)) < 0)
    {
        if (use_savedir && errno == ENOENT)
        {
            /* No such game in SAVEDIR */
            return TRUE;
        }
	perror(file);
	return FALSE;
    }

    fflush(stdout);

    encread(buf, strlen(version) + 1, inf);

    if (strcmp(buf, version) != 0)
    {
	printf("Sorry, saved game is out of date.\n");
	return FALSE;
    }

    /*
     * Get the lines and columns from the previous game
     */

    encread(buf, 80, inf);
    sscanf(buf, "%d x %d\n", &oldline, &oldcol);
    fstat(inf, &sbuf2);
    fflush(stdout);

    /*
     * Set the new terminal and make sure we aren't going to a smaller screen.
     */

    initscr();
   
    if (COLS < oldcol || LINES < oldline) {
        endwin();
	printf("\nCannot restart the game on a smaller screen.\n");
	return FALSE;
    }

    cw = newwin(LINES, COLS, 0, 0);
    mw = newwin(LINES, COLS, 0, 0);
    hw = newwin(LINES, COLS, 0, 0);
    msgw = newwin(4, COLS, 0, 0);
    keypad(cw,1);
    keypad(msgw,1);

    mpos = 0;
    mvwprintw(cw, 0, 0, "%s: %s", file, ctime(&sbuf2.st_mtime));

    /*
     * defeat multiple restarting from the same place
     */
    if (!wizard) {
	if (sbuf2.st_nlink != 1) {
            endwin();
	    printf("\nCannot restore from a linked file\n");
	    return FALSE;
	}
    }

    if (rs_restore_file(inf) != 0)
    {
        endwin();
        printf("\nCannot restore file\n");
        return(FALSE);
    }

    if (!wizard)
    {
	if (unlink(file) < 0) {
            close(inf); /* only close if system insists */
            if (unlink(file) < 0) {
                endwin();
	        printf("\nCannot unlink file\n");
	        return FALSE;
            }
	}
    }

    if (pstats.s_hpt <= 0) {
        endwin();
        printf("This character is already dead.\n");
        return FALSE;
    }

    environ = envp;
    strcpy(file_name, file);
    setup();
    clearok(curscr, TRUE);
    touchwin(cw);
    srand(getpid());
    playit();
    /*NOTREACHED*/ 
    return(FALSE);
}

/*
 * perform an encrypted write
 */
encwrite(start, size, outf)
register char *start;
register unsigned size;
register FILE *outf;
{
    register char *ep;
    register num_written = 0;

    ep = encstr;

    while (size--)
    {
	if (putc(*start++ ^ *ep++, outf) == EOF && ferror(outf))
	    return(num_written);
	num_written++;
	if (*ep == '\0')
	    ep = encstr;
    }
    return(num_written);
}

/*
 * perform an encrypted read
 */
encread(start, size, inf)
register char *start;
register unsigned size;
register int inf;
{
    register char *ep;
    register int read_size;

    if ((read_size = read(inf, start, size)) == -1 || read_size == 0)
	return read_size;

    ep = encstr;

    size = read_size;
    while (size--)
    {
	*start++ ^= *ep++;
	if (*ep == '\0')
	    ep = encstr;
    }
    return read_size;
}