nkeynes@102: /**
nkeynes@561:  * $Id$
nkeynes@102:  * 
nkeynes@102:  * DC-load syscall implementation.
nkeynes@102:  *
nkeynes@102:  * Copyright (c) 2005 Nathan Keynes.
nkeynes@102:  *
nkeynes@102:  * This program is free software; you can redistribute it and/or modify
nkeynes@102:  * it under the terms of the GNU General Public License as published by
nkeynes@102:  * the Free Software Foundation; either version 2 of the License, or
nkeynes@102:  * (at your option) any later version.
nkeynes@102:  *
nkeynes@102:  * This program is distributed in the hope that it will be useful,
nkeynes@102:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
nkeynes@102:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nkeynes@102:  * GNU General Public License for more details.
nkeynes@102:  */
nkeynes@102: 
nkeynes@102: #include <stdio.h>
nkeynes@422: #include <unistd.h>
nkeynes@422: #include <fcntl.h>
nkeynes@422: 
nkeynes@102: #include "dream.h"
nkeynes@422: #include "mem.h"
nkeynes@182: #include "dreamcast.h"
nkeynes@102: #include "syscall.h"
nkeynes@564: #include "sh4/sh4.h"
nkeynes@102: 
nkeynes@102: #define SYS_READ 0
nkeynes@102: #define SYS_WRITE 1
nkeynes@102: #define SYS_OPEN 2
nkeynes@102: #define SYS_CLOSE 3
nkeynes@102: #define SYS_CREAT 4
nkeynes@102: #define SYS_LINK 5
nkeynes@102: #define SYS_UNLINK 6
nkeynes@102: #define SYS_CHDIR 7
nkeynes@102: #define SYS_CHMOD 8
nkeynes@102: #define SYS_LSEEK 9
nkeynes@102: #define SYS_FSTAT 10
nkeynes@102: #define SYS_TIME 11
nkeynes@102: #define SYS_STAT 12
nkeynes@102: #define SYS_UTIME 13
nkeynes@102: #define SYS_ASSIGNWRKMEM 14
nkeynes@102: #define SYS_EXIT 15
nkeynes@102: #define SYS_OPENDIR 16
nkeynes@102: #define SYS_CLOSEDIR 17
nkeynes@102: #define SYS_READDIR 18
nkeynes@102: #define SYS_GETHOSTINFO 19
nkeynes@102: 
nkeynes@102: #define SYS_MAGIC 0xDEADBEEF
nkeynes@102: #define SYS_MAGIC_ADDR 0x8c004004
nkeynes@102: #define SYSCALL_ADDR 0x8c004008
nkeynes@102: 
nkeynes@209: static gboolean dcload_allow_unsafe = FALSE;
nkeynes@182: 
nkeynes@209: void dcload_set_allow_unsafe( gboolean allow )
nkeynes@182: {
nkeynes@209:     dcload_allow_unsafe = allow;
nkeynes@209: }
nkeynes@209: 
nkeynes@209: #define MAX_OPEN_FDS 16
nkeynes@209: /**
nkeynes@209:  * Mapping from emulator fd to real fd (so we can limit read/write
nkeynes@209:  * to only fds we've explicitly granted access to).
nkeynes@209:  */
nkeynes@209: int open_fds[MAX_OPEN_FDS];
nkeynes@209: 
nkeynes@209: int dcload_alloc_fd() 
nkeynes@209: {
nkeynes@209:     int i;
nkeynes@209:     for( i=0; i<MAX_OPEN_FDS; i++ ) {
nkeynes@736:         if( open_fds[i] == -1 ) {
nkeynes@736:             return i;
nkeynes@736:         }
nkeynes@209:     }
nkeynes@209:     return -1;
nkeynes@182: }
nkeynes@182: 
nkeynes@102: void dcload_syscall( uint32_t syscall_id ) 
nkeynes@102: {
nkeynes@422:     // uint32_t syscall = sh4r.r[4];
nkeynes@209:     int fd;
nkeynes@102:     switch( sh4r.r[4] ) {
nkeynes@102:     case SYS_READ:
nkeynes@736:         fd = sh4r.r[5];
nkeynes@736:         if( fd < 0 || fd >= MAX_OPEN_FDS || open_fds[fd] == -1 ) {
nkeynes@736:             sh4r.r[0] = -1;
nkeynes@736:         } else {
nkeynes@736:             sh4ptr_t buf = mem_get_region( sh4r.r[6] );
nkeynes@736:             int length = sh4r.r[7];
nkeynes@736:             sh4r.r[0] = read( open_fds[fd], buf, length );
nkeynes@736:         }
nkeynes@736:         break;
nkeynes@209:     case SYS_WRITE:
nkeynes@736:         fd = sh4r.r[5];
nkeynes@736:         if( fd < 0 || fd >= MAX_OPEN_FDS || open_fds[fd] == -1 ) {
nkeynes@736:             sh4r.r[0] = -1;
nkeynes@736:         } else {
nkeynes@736:             sh4ptr_t buf = mem_get_region( sh4r.r[6] );
nkeynes@736:             int length = sh4r.r[7];
nkeynes@736:             sh4r.r[0] = write( open_fds[fd], buf, length );
nkeynes@736:         }
nkeynes@736:         break;
nkeynes@209:     case SYS_LSEEK:
nkeynes@736:         fd = sh4r.r[5];
nkeynes@736:         if( fd < 0 || fd >= MAX_OPEN_FDS || open_fds[fd] == -1 ) {
nkeynes@736:             sh4r.r[0] = -1;
nkeynes@736:         } else {
nkeynes@736:             sh4r.r[0] = lseek( open_fds[fd], sh4r.r[6], sh4r.r[7] );
nkeynes@736:         }
nkeynes@736:         break;
nkeynes@209: 
nkeynes@736:         /* Secure access only */
nkeynes@209:     case SYS_OPEN:
nkeynes@736:         if( dcload_allow_unsafe ) {
nkeynes@736:             fd = dcload_alloc_fd();
nkeynes@736:             if( fd == -1 ) {
nkeynes@736:                 sh4r.r[0] = -1;
nkeynes@736:             } else {
nkeynes@736:                 char *filename = (char *)mem_get_region( sh4r.r[5] );
nkeynes@736:                 int realfd = open( filename, sh4r.r[6] );
nkeynes@736:                 open_fds[fd] = realfd;
nkeynes@736:                 sh4r.r[0] = realfd;
nkeynes@736:             }
nkeynes@736:         } else {
nkeynes@736:             ERROR( "Denying access to local filesystem" );
nkeynes@736:             sh4r.r[0] = -1;
nkeynes@736:         }
nkeynes@736:         break;
nkeynes@209:     case SYS_CLOSE:
nkeynes@736:         if( dcload_allow_unsafe ) {
nkeynes@736:             fd = sh4r.r[5];
nkeynes@736:             if( fd < 0 || fd >= MAX_OPEN_FDS || open_fds[fd] == -1 ) {
nkeynes@736:                 sh4r.r[0] = -1;
nkeynes@736:             } else {
nkeynes@736:                 if( open_fds[fd] > 2 ) {
nkeynes@736:                     sh4r.r[0] = close( open_fds[fd] );
nkeynes@736:                 } else {
nkeynes@736:                     /* Don't actually close real fds 0-2 */
nkeynes@736:                     sh4r.r[0] = 0;
nkeynes@736:                 }
nkeynes@736:                 open_fds[fd] = -1;
nkeynes@736:             }
nkeynes@736:         }
nkeynes@736:         break;
nkeynes@102:     case SYS_EXIT:
nkeynes@736:         if( dcload_allow_unsafe ) {
nkeynes@736:             dreamcast_shutdown();
nkeynes@736:             exit( sh4r.r[5] );
nkeynes@736:         } else {
nkeynes@736:             dreamcast_stop();
nkeynes@736:         }
nkeynes@102:     default:
nkeynes@736:         sh4r.r[0] = -1;
nkeynes@102:     }
nkeynes@102: 
nkeynes@102: }
nkeynes@102: 
nkeynes@102: void dcload_install() 
nkeynes@102: {
nkeynes@209:     memset( &open_fds, -1, sizeof(open_fds) );
nkeynes@209:     open_fds[0] = 0;
nkeynes@209:     open_fds[1] = 1;
nkeynes@209:     open_fds[2] = 2;
nkeynes@102:     syscall_add_hook_vector( 0xF0, SYSCALL_ADDR, dcload_syscall );
nkeynes@669:     mem_write_long( SYS_MAGIC_ADDR, SYS_MAGIC );
nkeynes@102: }