ilo-vm/source/ilo-safer.c

221 lines
6.3 KiB
C

/***************************************************************
crc's _ _
(_) | ___
| | |/ _ \ a tiny virtual computer
| | | (_) | 64kw RAM, 32-bit, Dual Stack, MISC
|_|_|\___/ ilo.c (c) charles childers
**************************************************************/
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#define T ds[sp] /* Top of Data Stack */
#define N ds[sp-1] /* Next on Data Stack */
#define R as[rp] /* Top of Address Stack */
#define V void
#define I int
#define C char
I ip, /* instruction pointer */
sp, /* data stack pointer */
rp, /* address stack pointer */
ds[33], /* data stack */
as[257], /* address stack */
m[65536]; /* memory */
C *blocks, /* name of block file (ilo.blocks) */
*rom; /* name of image (ilo.rom) */
/* the other variables are used by the various
functions for misc. purposes */
I a, b, f, s, d, l;
C i[1];
struct termios ot, nt;
V it() {
tcgetattr(STDIN_FILENO, &ot);
nt = ot;
nt.c_lflag &=(~ICANON & ~ECHO);
tcsetattr(STDIN_FILENO, TCSANOW, &nt);
}
V rt() { tcsetattr(STDIN_FILENO, TCSANOW, &ot); }
V p(char *s) { while(*s) putchar(*s++); }
V e(char *s) { p("E:"); p(s); p("\n"); exit(1); }
V dso() { if ((sp + 1) > 32) { e("DSO"); } }
V dsu() { if ((sp - 1) < 0) { e("DSU"); } }
V rso() { if ((rp + 1) > 256) { e("RSO"); } }
V rsu() { if ((rp - 1) < 0) { e("RSU"); } }
V dbz() { if (T == 0) { e("DBZ"); } }
V mem() { if (T < 0 || T > 65535) { e("MEM"); } }
V uli() { if (f == -1) { e("ULI"); } }
V usi() { if (f == -1) { e("URI"); } }
V urb() { if (f == -1) { e("URB"); } }
V uwb() { if (f == -1) { e("UWB"); } }
V push(I v) { dso(); ds[sp + 1] = v; sp += 1; }
I pop() { dsu(); sp -= 1; return ds[sp + 1]; }
V load_image() {
f = open(rom, O_RDONLY, 0666);
uli();
if (read(f, &m, 65536 * 4) < 0) { uli(); }
close(f);
ip = sp = rp = 0;
}
V save_image() {
f = open(rom, O_WRONLY, 0666);
usi();
if (write(f, &m, 65536 * 4) < 0) { usi(); }
close(f);
}
V block_common() {
b = pop(); /* block buffer */
a = pop(); /* block number */
if (lseek(f, 4096 * a, SEEK_SET) < 0) { e("LSEEK"); };
}
V read_block() {
f = open(blocks, O_RDONLY, 0666);
urb();
block_common();
if (read(f, m + b, 4096) < 0) { urb(); }
close(f);
}
V write_block() {
f = open(blocks, O_WRONLY, 0666);
uwb();
block_common();
if (write(f, m + b, 4096) < 0) { uwb(); }
close(f);
}
V save_ip() { rso(); rp += 1; R = ip; }
V symmetric() { if (b >= 0 && N < 0) { T += 1; N -= b; } }
V emit() { if (write(1, &i, 1) < 0) { exit(1); }; }
V bs() { i[0] = '\b'; emit();
i[0] = ' '; emit();
i[0] = '\b'; emit(); }
V li() { ip += 1; push(m[ip]); }
V du() { push(T); }
V dr() { ds[sp] = 0; sp -= 1; }
V sw() { a = T; T = N; N = a; }
V pu() { rso(); rp += 1; R = pop(); }
V po() { rsu(); push(R); rp -= 1; }
V ju() { ip = pop() - 1; }
V ca() { save_ip(); ip = pop() - 1; }
V cc() { a = pop(); if (pop()) { save_ip(); ip = a - 1; } }
V cj() { a = pop(); if (pop()) { ip = a - 1; } }
V re() { rsu(); ip = R; rp -= 1; }
V eq() { N = (N == T) ? -1 : 0; sp -= 1; }
V ne() { N = (N != T) ? -1 : 0; sp -= 1; }
V lt() { N = (N < T) ? -1 : 0; sp -= 1; }
V gt() { N = (N > T) ? -1 : 0; sp -= 1; }
V fe() { mem(); T = m[T]; }
V st() { mem(); m[T] = N; sp -= 2; }
V ad() { N += T; sp -= 1; }
V su() { N -= T; sp -= 1; }
V mu() { N *= T; sp -= 1; }
V di() { dbz();
a = T; b = N; T = b / a; N = b % a; symmetric(); }
V an() { N = T & N; sp -= 1; }
V or() { N = T | N; sp -= 1; }
V xo() { N = T ^ N; sp -= 1; }
V sl() { N = N << T; sp -= 1; }
V sr() { N = N >> T; sp -= 1; }
V cp() { size_t l = pop() * 4;
void *d = m + pop();
void *s = m + pop();
push((memcmp(s, d, l) == 0) ? -1 : 0);
}
V cy() { size_t l = pop() * 4;
void *d = m + pop();
void *s = m + pop();
memmove(d, s, l);
}
V ioa() { i[0] = (char)pop(); emit(); }
V iob() { if (read(0, &i, 1) < 0) { rt(); exit(1); }; push(i[0]);
(i[0] == 8 || i[0] == 127) ? bs() : emit(); }
V ioc() { read_block(); }
V iod() { write_block(); }
V ioe() { save_image(); }
V iof() { load_image(); ip = -1; }
V iog() { ip = 65536; }
V ioh() { push(sp); push(rp); }
V io() {
switch (pop()) {
case 0: ioa(); break; case 1: iob(); break;
case 2: ioc(); break; case 3: iod(); break;
case 4: ioe(); break; case 5: iof(); break;
case 6: iog(); break; case 7: ioh(); break;
default: break;
}
}
/* Using a switch here instead of a jump table to avoid */
/* some issues w/relocation stuff when building w/o libc */
V process(I o) {
switch (o) {
case 0: break; case 1: li(); break;
case 2: du(); break; case 3: dr(); break;
case 4: sw(); break; case 5: pu(); break;
case 6: po(); break; case 7: ju(); break;
case 8: ca(); break; case 9: cc(); break;
case 10: cj(); break; case 11: re(); break;
case 12: eq(); break; case 13: ne(); break;
case 14: lt(); break; case 15: gt(); break;
case 16: fe(); break; case 17: st(); break;
case 18: ad(); break; case 19: su(); break;
case 20: mu(); break; case 21: di(); break;
case 22: an(); break; case 23: or(); break;
case 24: xo(); break; case 25: sl(); break;
case 26: sr(); break; case 27: cp(); break;
case 28: cy(); break; case 29: io(); break;
default: break;
}
}
#define INST(n) ((opcode >> n) & 0xFF) != 0
V process_bundle(I opcode) {
if (INST(0)) process(opcode & 0xFF);
if (INST(8)) process((opcode >> 8) & 0xFF);
if (INST(16)) process((opcode >> 16) & 0xFF);
if (INST(24)) process((opcode >> 24) & 0xFF);
}
V execute() {
while (ip < 65536) {
process_bundle(m[ip]);
ip += 1;
}
}
V add_restrictions() {
#ifdef __OpenBSD__
unveil(blocks, "rw");
unveil(rom, "rw");
unveil(NULL, NULL);
pledge("stdio rpath wpath tty", NULL);
#endif
}
I main(I argc, C **argv) {
blocks = (argc > 1) ? argv[1] : "ilo.blocks";
rom = (argc > 2) ? argv[2] : "ilo.rom";
add_restrictions();
it(); load_image(); execute(); rt();
return 0;
}