/*
* 2ooM: The Master of Orion II Reverse Engineering Project
* Library for working with LBX archive files.
* Copyright (C) 2006-2008 Nick Bowler
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see .
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include
#include
#include
#include
#include
#include
#include
#include
#include "byteorder.h"
#include "misc.h"
#include "lbx.h"
#define LBX_MAGIC 0x0000fead
int lbx_errno = 0;
struct lbx_state {
const char *name;
unsigned char *mem;
size_t memsize;
FILE *f;
long foff;
uint16_t nfiles;
uint32_t offsets[];
};
struct lbx_state *lbx_fopen(FILE *f, const char *name)
{
struct lbx_state *new = NULL;
uint16_t nfiles, version;
uint32_t magic;
if (fread(&nfiles, sizeof nfiles, 1, f) != 1) goto readerr;
if (fread(&magic, sizeof magic, 1, f) != 1) goto readerr;
if (fread(&version, sizeof version, 1, f) != 1) goto readerr;
nfiles = letohs(nfiles);
magic = letohl(magic);
version = letohs(version);
if (magic != LBX_MAGIC) {
lbx_errno = LBX_EMAGIC;
return NULL;
}
new = malloc(sizeof *new + (nfiles+1)*(sizeof *new->offsets));
if (!new) {
lbx_errno = -errno;
return NULL;
}
*new = (struct lbx_state){
.name = name,
.nfiles = nfiles,
.f = f,
.foff = sizeof nfiles + sizeof magic + sizeof version,
};
if (fread(new->offsets, sizeof *new->offsets, nfiles+1, f) != nfiles+1)
goto readerr;
new->foff += sizeof *new->offsets * (nfiles+1);
return new;
readerr:
if (feof(f)) {
lbx_errno = LBX_EEOF;
} else {
lbx_errno = -errno;
}
free(new);
return NULL;
}
static int _lbx_memcpy(void *dest, struct lbx_state *src, size_t size)
{
if (src->foff + size > src->memsize)
return -1;
memcpy(dest, src->mem + src->foff, size);
src->foff += size;
return 0;
}
struct lbx_state *lbx_mopen(void *_mem, size_t size, const char *name)
{
struct lbx_state *new = NULL;
struct lbx_state tmp = { .mem = _mem, .memsize = size };
uint16_t nfiles, version;
uint32_t magic;
if (_lbx_memcpy(&nfiles, &tmp, sizeof nfiles) == -1) goto eof;
if (_lbx_memcpy(&magic, &tmp, sizeof magic) == -1) goto eof;
if (_lbx_memcpy(&version, &tmp, sizeof version) == -1) goto eof;
nfiles = letohs(nfiles);
magic = letohl(magic);
version = letohs(version);
if (magic != LBX_MAGIC) {
lbx_errno = LBX_EMAGIC;
return NULL;
}
new = malloc(sizeof *new + (nfiles+1)*(sizeof *new->offsets));
if (!new) {
lbx_errno = -errno;
return NULL;
}
*new = (struct lbx_state){
.name = name,
.nfiles = nfiles,
.mem = _mem,
.memsize = size,
.foff = tmp.foff,
};
if (_lbx_memcpy(new->offsets, new, (nfiles+1)*(sizeof *new->offsets)))
goto eof;
return new;
eof:
free(new);
lbx_errno = LBX_EEOF;
return NULL;
}
struct lbx_state *lbx_open(const char *path)
{
struct lbx_state *new = NULL;
FILE *f;
if ((f = fopen(path, "rb"))) {
const char *name = strrchr(path, '/');
new = lbx_fopen(f, name ? name+1 : path);
} else {
lbx_errno = -errno;
}
return new;
}
size_t lbx_numfiles(struct lbx_state *lbx)
{
return lbx->nfiles;
}
int lbx_stat(struct lbx_state *lbx, size_t index, struct lbx_statbuf *buf)
{
static char str[256]; /* FIXME */
if (index >= lbx->nfiles) {
buf->name = NULL;
lbx_errno = LBX_ERANGE;
return -1;
}
snprintf(str, sizeof str, "%s.%03d", lbx->name, index);
buf->name = str;
buf->size = lbx->offsets[index+1] - lbx->offsets[index];
return 0;
}
static size_t
_lbx_mextract(struct lbx_state *lbx, size_t base, size_t len, FILE *of)
{
size_t rc;
assert(lbx->mem);
assert(base + len <= lbx->memsize);
rc = fwrite(lbx->mem + base, 1, len, of);
if (rc < len)
lbx_errno = -errno;
return rc;
}
static size_t
_lbx_fextract(struct lbx_state *lbx, size_t base, size_t len, FILE *of)
{
unsigned char buf[1024];
size_t rc, written = 0;
assert(lbx->f);
if (_lbx_fseek(lbx->f, &lbx->foff, base) == -1)
return 0;
while (len) {
size_t amt = MIN(len, sizeof buf);
rc = fread(buf, 1, amt, lbx->f);
lbx->foff += rc;
len -= rc;
if (rc < amt) {
if (feof(lbx->f)) lbx_errno = LBX_EEOF;
else lbx_errno = -errno;
break;
}
rc = fwrite(buf, 1, amt, of);
written += rc;
if (rc < amt) {
lbx_errno = -errno;
break;
}
}
return written;
}
size_t lbx_extract(struct lbx_state *lbx, size_t index, FILE *of)
{
size_t base, len;
if (index >= lbx->nfiles) {
lbx_errno = LBX_ERANGE;
return 0;
}
base = lbx->offsets[index];
len = lbx->offsets[index+1] - lbx->offsets[index];
if (lbx->mem)
return _lbx_mextract(lbx, base, len, of);
return _lbx_fextract(lbx, base, len, of);
}
void *lbx_mmap(struct lbx_state *lbx, size_t index, size_t *len)
{
unsigned char *mapping;
struct stat statbuf;
size_t base;
if (index >= lbx->nfiles) {
lbx_errno = LBX_ERANGE;
return NULL;
}
base = lbx->offsets[index];
*len = lbx->offsets[index+1] - lbx->offsets[index];
if (lbx->mem)
return lbx->mem + base;
if (fstat(fileno(lbx->f), &statbuf) == -1) {
lbx_errno = -errno;
return NULL;
}
mapping = mmap(NULL, statbuf.st_size, PROT_READ, 0, fileno(lbx->f), 0);
if (mapping == MAP_FAILED) {
lbx_errno = -errno;
return NULL;
}
lbx->mem = mapping;
lbx->memsize = statbuf.st_size;
return mapping + base;
}
void lbx_close(struct lbx_state *lbx)
{
if (!lbx) return;
if (lbx->f) {
fclose(lbx->f);
if (lbx->mem) {
munmap(lbx->mem, lbx->memsize);
}
}
free(lbx);
}
const char *lbx_strerror(void)
{
if (lbx_errno < 0)
return strerror(-lbx_errno);
switch (lbx_errno) {
case LBX_ESUCCESS: return "Success";
case LBX_EMAGIC: return "Bad magic number";
case LBX_EEOF: return "Unexpected end-of-file";
case LBX_ERANGE: return "Index out of range";
case LBX_EFORMAT: return "Invalid file format";
}
return "Unknown error";
}