| dc2e0dc7 |
/* WARNING: This version also supports dopen for descriptor opening and
* is not compatible with the original version. -- T. Kojm
*
* This file is part of libmspack.
* (C) 2003-2004 Stuart Caie.
*
* libmspack is free software; you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License (LGPL) version 2.1
*
* For further details, see the file COPYING.LIB distributed with libmspack
*/
/* Cabinet (.CAB) files are a form of file archive. Each cabinet contains
* "folders", which are compressed spans of data. Each cabinet has
* "files", whose metadata is in the cabinet header, but whose actual data
* is stored compressed in one of the "folders". Cabinets can span more
* than one physical file on disk, in which case they are a "cabinet set",
* and usually the last folder of each cabinet extends into the next
* cabinet.
*
* For a complete description of the format, get the official Microsoft
* CAB SDK. It can be found at the following URL:
*
* http://msdn.microsoft.com/library/en-us/dncabsdk/html/cabdl.asp
*
* It is a self-extracting ZIP file, which can be extracted with the unzip
* command.
*/
/* CAB decompression implementation */
#if HAVE_CONFIG_H
#include "clamav-config.h"
#endif
#include <mspack.h>
#include <system.h>
#include <cab.h>
/* Notes on compliance with cabinet specification:
*
* One of the main changes between cabextract 0.6 and libmspack's cab
* decompressor is the move from block-oriented decompression to
* stream-oriented decompression.
*
* cabextract would read one data block from disk, decompress it with the
* appropriate method, then write the decompressed data. The CAB
* specification is specifically designed to work like this, as it ensures
* compression matches do not span the maximum decompressed block size
* limit of 32kb.
*
* However, the compression algorithms used are stream oriented, with
* specific hacks added to them to enforce the "individual 32kb blocks"
* rule in CABs. In other file formats, they do not have this limitation.
*
* In order to make more generalised decompressors, libmspack's CAB
* decompressor has moved from being block-oriented to more stream
* oriented. This also makes decompression slightly faster.
*
* However, this leads to incompliance with the CAB specification. The
* CAB controller can no longer ensure each block of input given to the
* decompressors is matched with their output. The "decompressed size" of
* each individual block is thrown away.
*
* Each CAB block is supposed to be seen as individually compressed. This
* means each consecutive data block can have completely different
* "uncompressed" sizes, ranging from 1 to 32768 bytes. However, in
* reality, all data blocks in a folder decompress to exactly 32768 bytes,
* excepting the final block.
*
* Given this situation, the decompression algorithms are designed to
* realign their input bitstreams on 32768 output-byte boundaries, and
* various other special cases have been made. libmspack will not
* correctly decompress LZX or Quantum compressed folders where the blocks
* do not follow this "32768 bytes until last block" pattern. It could be
* implemented if needed, but hopefully this is not necessary -- it has
* not been seen in over 3Gb of CAB archives.
*/
/* prototypes */
static struct mscabd_cabinet * cabd_open(
struct mscab_decompressor *base, char *filename);
static struct mscabd_cabinet * cabd_dopen(
struct mscab_decompressor *base, int desc);
static void cabd_close(
struct mscab_decompressor *base, struct mscabd_cabinet *origcab);
static int cabd_read_headers(
struct mspack_system *sys, struct mspack_file *fh,
struct mscabd_cabinet_p *cab, off_t offset, int quiet);
static char *cabd_read_string(
struct mspack_system *sys, struct mspack_file *fh,
struct mscabd_cabinet_p *cab, int *error);
static struct mscabd_cabinet *cabd_search(
struct mscab_decompressor *base, char *filename);
static struct mscabd_cabinet *cabd_dsearch(
struct mscab_decompressor *base, int desc);
static int cabd_find(
struct mscab_decompressor_p *this, unsigned char *buf,
struct mspack_file *fh, char *filename, int desc, off_t flen,
unsigned int *firstlen, struct mscabd_cabinet_p **firstcab);
static int cabd_prepend(
struct mscab_decompressor *base, struct mscabd_cabinet *cab,
struct mscabd_cabinet *prevcab);
static int cabd_append(
struct mscab_decompressor *base, struct mscabd_cabinet *cab,
struct mscabd_cabinet *nextcab);
static int cabd_merge(
struct mscab_decompressor *base, struct mscabd_cabinet *lcab,
struct mscabd_cabinet *rcab);
static int cabd_extract(
struct mscab_decompressor *base, struct mscabd_file *file, char *filename);
static int cabd_init_decomp(
struct mscab_decompressor_p *this, unsigned int ct);
static void cabd_free_decomp(
struct mscab_decompressor_p *this);
static int cabd_sys_read(
struct mspack_file *file, void *buffer, int bytes);
static int cabd_sys_write(
struct mspack_file *file, void *buffer, int bytes);
static int cabd_sys_read_block(
struct mspack_system *sys, struct mscabd_decompress_state *d, int *out,
int ignore_cksum);
static unsigned int cabd_checksum(
unsigned char *data, unsigned int bytes, unsigned int cksum);
static struct noned_state *noned_init(
struct mspack_system *sys, struct mspack_file *in, struct mspack_file *out,
int bufsize);
static int noned_decompress(
struct noned_state *s, off_t bytes);
static void noned_free(
struct noned_state *state);
static int cabd_param(
struct mscab_decompressor *base, int param, int value);
static int cabd_error(
struct mscab_decompressor *base);
/***************************************
* MSPACK_CREATE_CAB_DECOMPRESSOR
***************************************
* constructor
*/
struct mscab_decompressor *
mspack_create_cab_decompressor(struct mspack_system *sys)
{
struct mscab_decompressor_p *this = NULL;
if (!sys) sys = mspack_default_system;
if (!mspack_valid_system(sys)) return NULL;
if ((this = sys->alloc(sys, sizeof(struct mscab_decompressor_p)))) {
this->base.open = &cabd_open;
this->base.dopen = &cabd_dopen;
this->base.close = &cabd_close;
this->base.search = &cabd_search;
this->base.dsearch = &cabd_dsearch;
this->base.extract = &cabd_extract;
this->base.prepend = &cabd_prepend;
this->base.append = &cabd_append;
this->base.set_param = &cabd_param;
this->base.last_error = &cabd_error;
this->system = sys;
this->d = NULL;
this->error = MSPACK_ERR_OK;
this->param[MSCABD_PARAM_SEARCHBUF] = 32768;
this->param[MSCABD_PARAM_FIXMSZIP] = 0;
this->param[MSCABD_PARAM_DECOMPBUF] = 4096;
}
return (struct mscab_decompressor *) this;
}
/***************************************
* MSPACK_DESTROY_CAB_DECOMPRESSOR
***************************************
* destructor
*/
void mspack_destroy_cab_decompressor(struct mscab_decompressor *base) {
struct mscab_decompressor_p *this = (struct mscab_decompressor_p *) base;
if (this) {
struct mspack_system *sys = this->system;
cabd_free_decomp(this);
if (this->d) {
if (this->d->infh) sys->close(this->d->infh);
sys->free(this->d);
}
sys->free(this);
}
}
/***************************************
* CABD_OPEN
***************************************
* opens a file and tries to read it as a cabinet file
*/
static struct mscabd_cabinet *cabd_open(struct mscab_decompressor *base,
char *filename)
{
struct mscab_decompressor_p *this = (struct mscab_decompressor_p *) base;
struct mscabd_cabinet_p *cab = NULL;
struct mspack_system *sys;
struct mspack_file *fh;
int error;
if (!base) return NULL;
sys = this->system;
if ((fh = sys->open(sys, filename, MSPACK_SYS_OPEN_READ))) {
if ((cab = sys->alloc(sys, sizeof(struct mscabd_cabinet_p)))) {
cab->base.filename = filename;
/* cab->base.desc = 0; */
error = cabd_read_headers(sys, fh, cab, (off_t) 0, 0);
if (error) {
cabd_close(base, (struct mscabd_cabinet *) cab);
cab = NULL;
}
this->error = error;
}
else {
this->error = MSPACK_ERR_NOMEMORY;
}
sys->close(fh);
}
else {
this->error = MSPACK_ERR_OPEN;
}
return (struct mscabd_cabinet *) cab;
}
static struct mscabd_cabinet *cabd_dopen(struct mscab_decompressor *base,
int desc)
{
struct mscab_decompressor_p *this = (struct mscab_decompressor_p *) base;
struct mscabd_cabinet_p *cab = NULL;
struct mspack_system *sys;
struct mspack_file *fh;
int error;
if (!base) return NULL;
sys = this->system;
if ((fh = sys->dopen(sys, desc, MSPACK_SYS_OPEN_READ))) {
if ((cab = sys->alloc(sys, sizeof(struct mscabd_cabinet_p)))) {
cab->base.filename = "descriptor"; |
| dc2e0dc7 |
error = cabd_read_headers(sys, fh, cab, (off_t) 0, 0);
if (error) {
cabd_close(base, (struct mscabd_cabinet *) cab);
cab = NULL;
}
this->error = error;
}
else {
this->error = MSPACK_ERR_NOMEMORY;
}
sys->close(fh);
}
else {
this->error = MSPACK_ERR_OPEN;
}
return (struct mscabd_cabinet *) cab;
}
/***************************************
* CABD_CLOSE
***************************************
* frees all memory associated with a given mscabd_cabinet.
*/
static void cabd_close(struct mscab_decompressor *base,
struct mscabd_cabinet *origcab)
{
struct mscab_decompressor_p *this = (struct mscab_decompressor_p *) base;
struct mscabd_folder_data *dat, *ndat;
struct mscabd_cabinet *cab, *ncab;
struct mscabd_folder *fol, *nfol;
struct mscabd_file *fi, *nfi;
struct mspack_system *sys;
if (!base) return;
sys = this->system;
this->error = MSPACK_ERR_OK;
while (origcab) {
/* free files */
for (fi = origcab->files; fi; fi = nfi) {
nfi = fi->next;
sys->free(fi->filename);
sys->free(fi);
}
/* free folders */
for (fol = origcab->folders; fol; fol = nfol) {
nfol = fol->next;
/* free folder decompression state if it has been decompressed */
if (this->d && (this->d->folder == (struct mscabd_folder_p *) fol)) {
if (this->d->infh) sys->close(this->d->infh);
cabd_free_decomp(this);
sys->free(this->d);
this->d = NULL;
}
/* free folder data segments */
for (dat = ((struct mscabd_folder_p *)fol)->data.next; dat; dat = ndat) {
ndat = dat->next;
sys->free(dat);
}
sys->free(fol);
}
/* free predecessor cabinets (and the original cabinet's strings) */
for (cab = origcab; cab; cab = ncab) {
ncab = cab->prevcab;
sys->free(cab->prevname);
sys->free(cab->nextname);
sys->free(cab->previnfo);
sys->free(cab->nextinfo);
if (cab != origcab) sys->free(cab);
}
/* free successor cabinets */
for (cab = origcab->nextcab; cab; cab = ncab) {
ncab = cab->nextcab;
sys->free(cab->prevname);
sys->free(cab->nextname);
sys->free(cab->previnfo);
sys->free(cab->nextinfo);
sys->free(cab);
}
/* free actual cabinet structure */
cab = origcab->next;
sys->free(origcab);
/* repeat full procedure again with the cab->next pointer (if set) */
origcab = cab;
}
}
/***************************************
* CABD_READ_HEADERS
***************************************
* reads the cabinet file header, folder list and file list.
* fills out a pre-existing mscabd_cabinet structure, allocates memory
* for folders and files as necessary
*/
static int cabd_read_headers(struct mspack_system *sys,
struct mspack_file *fh,
struct mscabd_cabinet_p *cab,
off_t offset, int quiet)
{
int num_folders, num_files, folder_resv, i, x;
struct mscabd_folder_p *fol, *linkfol = NULL;
struct mscabd_file *file, *linkfile = NULL;
unsigned char buf[64];
/* initialise pointers */
cab->base.next = NULL;
cab->base.files = NULL;
cab->base.folders = NULL;
cab->base.prevcab = cab->base.nextcab = NULL;
cab->base.prevname = cab->base.nextname = NULL;
cab->base.previnfo = cab->base.nextinfo = NULL;
cab->base.base_offset = offset;
/* seek to CFHEADER */
if (sys->seek(fh, offset, MSPACK_SYS_SEEK_START)) {
return MSPACK_ERR_SEEK;
}
/* read in the CFHEADER */
if (sys->read(fh, &buf[0], cfhead_SIZEOF) != cfhead_SIZEOF) {
return MSPACK_ERR_READ;
}
/* check for "MSCF" signature */
if (EndGetI32(&buf[cfhead_Signature]) != 0x4643534D) {
return MSPACK_ERR_SIGNATURE;
}
/* some basic header fields */
cab->base.length = EndGetI32(&buf[cfhead_CabinetSize]);
cab->base.set_id = EndGetI16(&buf[cfhead_SetID]);
cab->base.set_index = EndGetI16(&buf[cfhead_CabinetIndex]);
/* get the number of folders */
num_folders = EndGetI16(&buf[cfhead_NumFolders]);
if (num_folders == 0) {
if (!quiet) sys->message(fh, "no folders in cabinet.");
return MSPACK_ERR_DATAFORMAT;
}
/* get the number of files */
num_files = EndGetI16(&buf[cfhead_NumFiles]);
if (num_files == 0) {
if (!quiet) sys->message(fh, "no files in cabinet.");
return MSPACK_ERR_DATAFORMAT;
}
/* check cabinet version */
if ((buf[cfhead_MajorVersion] != 1) && (buf[cfhead_MinorVersion] != 3)) {
if (!quiet) sys->message(fh, "WARNING; cabinet version is not 1.3");
}
/* read the reserved-sizes part of header, if present */
cab->base.flags = EndGetI16(&buf[cfhead_Flags]);
if (cab->base.flags & cfheadRESERVE_PRESENT) {
if (sys->read(fh, &buf[0], cfheadext_SIZEOF) != cfheadext_SIZEOF) {
return MSPACK_ERR_READ;
}
cab->base.header_resv = EndGetI16(&buf[cfheadext_HeaderReserved]);
folder_resv = buf[cfheadext_FolderReserved];
cab->block_resv = buf[cfheadext_DataReserved];
if (cab->base.header_resv > 60000) {
if (!quiet) sys->message(fh, "WARNING; reserved header > 60000.");
}
/* skip the reserved header */
if (cab->base.header_resv) {
if (sys->seek(fh, (off_t) cab->base.header_resv, MSPACK_SYS_SEEK_CUR)) {
return MSPACK_ERR_SEEK;
}
}
}
else {
cab->base.header_resv = 0;
folder_resv = 0;
cab->block_resv = 0;
}
/* read name and info of preceeding cabinet in set, if present */
if (cab->base.flags & cfheadPREV_CABINET) {
cab->base.prevname = cabd_read_string(sys, fh, cab, &x); if (x) return x;
cab->base.previnfo = cabd_read_string(sys, fh, cab, &x); if (x) return x;
}
/* read name and info of next cabinet in set, if present */
if (cab->base.flags & cfheadNEXT_CABINET) {
cab->base.nextname = cabd_read_string(sys, fh, cab, &x); if (x) return x;
cab->base.nextinfo = cabd_read_string(sys, fh, cab, &x); if (x) return x;
}
/* read folders */
for (i = 0; i < num_folders; i++) {
if (sys->read(fh, &buf[0], cffold_SIZEOF) != cffold_SIZEOF) {
return MSPACK_ERR_READ;
}
if (folder_resv) {
if (sys->seek(fh, (off_t) folder_resv, MSPACK_SYS_SEEK_CUR)) {
return MSPACK_ERR_SEEK;
}
}
if (!(fol = sys->alloc(sys, sizeof(struct mscabd_folder_p)))) {
return MSPACK_ERR_NOMEMORY;
}
fol->base.next = NULL;
fol->base.comp_type = EndGetI16(&buf[cffold_CompType]);
fol->base.num_blocks = EndGetI16(&buf[cffold_NumBlocks]);
fol->data.next = NULL;
fol->data.cab = (struct mscabd_cabinet_p *) cab;
fol->data.offset = offset + (off_t)
( (unsigned int) EndGetI32(&buf[cffold_DataOffset]) );
fol->merge_prev = NULL;
fol->merge_next = NULL;
/* link folder into list of folders */
if (!linkfol) cab->base.folders = (struct mscabd_folder *) fol;
else linkfol->base.next = (struct mscabd_folder *) fol;
linkfol = fol;
}
/* read files */
for (i = 0; i < num_files; i++) {
if (sys->read(fh, &buf[0], cffile_SIZEOF) != cffile_SIZEOF) {
return MSPACK_ERR_READ;
}
if (!(file = sys->alloc(sys, sizeof(struct mscabd_file)))) {
return MSPACK_ERR_NOMEMORY;
}
file->next = NULL;
file->length = EndGetI32(&buf[cffile_UncompressedSize]);
file->attribs = EndGetI16(&buf[cffile_Attribs]);
file->offset = EndGetI32(&buf[cffile_FolderOffset]);
/* set folder pointer */
x = EndGetI16(&buf[cffile_FolderIndex]);
if (x < cffileCONTINUED_FROM_PREV) {
/* normal folder index; count up to the correct folder. the folder
* pointer will be NULL if folder index is invalid */
struct mscabd_folder *ifol = cab->base.folders;
while (x--) if (ifol) ifol = ifol->next;
file->folder = ifol;
if (!ifol) {
sys->free(file);
D(("invalid folder index"))
return MSPACK_ERR_DATAFORMAT;
}
}
else {
/* either CONTINUED_TO_NEXT, CONTINUED_FROM_PREV or
* CONTINUED_PREV_AND_NEXT */
if ((x == cffileCONTINUED_TO_NEXT) ||
(x == cffileCONTINUED_PREV_AND_NEXT))
{
/* get last folder */
struct mscabd_folder *ifol = cab->base.folders;
while (ifol->next) ifol = ifol->next;
file->folder = ifol;
/* set "merge next" pointer */
fol = (struct mscabd_folder_p *) ifol;
if (!fol->merge_next) fol->merge_next = file;
}
if ((x == cffileCONTINUED_FROM_PREV) ||
(x == cffileCONTINUED_PREV_AND_NEXT))
{
/* get first folder */
file->folder = cab->base.folders;
/* set "merge prev" pointer */
fol = (struct mscabd_folder_p *) file->folder;
if (!fol->merge_prev) fol->merge_prev = file;
}
}
/* get time */
x = EndGetI16(&buf[cffile_Time]);
file->time_h = x >> 11;
file->time_m = (x >> 5) & 0x3F;
file->time_s = (x << 1) & 0x3E;
/* get date */
x = EndGetI16(&buf[cffile_Date]);
file->date_d = x & 0x1F;
file->date_m = (x >> 5) & 0xF;
file->date_y = (x >> 9) + 1980;
/* get filename */
file->filename = cabd_read_string(sys, fh, cab, &x);
if (x) {
sys->free(file);
return x;
}
/* link file entry into file list */
if (!linkfile) cab->base.files = file;
else linkfile->next = file;
linkfile = file;
}
return MSPACK_ERR_OK;
}
static char *cabd_read_string(struct mspack_system *sys,
struct mspack_file *fh,
struct mscabd_cabinet_p *cab, int *error)
{
off_t base = sys->tell(fh);
char buf[256], *str;
unsigned int len, i, ok;
/* read up to 256 bytes */
len = sys->read(fh, &buf[0], 256);
/* search for a null terminator in the buffer */
for (i = 0, ok = 0; i < len; i++) if (!buf[i]) { ok = 1; break; }
if (!ok) {
*error = MSPACK_ERR_DATAFORMAT;
return NULL;
}
len = i + 1;
/* set the data stream to just after the string and return */
if (sys->seek(fh, base + (off_t)len, MSPACK_SYS_SEEK_START)) {
*error = MSPACK_ERR_SEEK;
return NULL;
}
if (!(str = sys->alloc(sys, len))) {
*error = MSPACK_ERR_NOMEMORY;
return NULL;
}
sys->copy(&buf[0], str, len);
*error = MSPACK_ERR_OK;
return str;
}
/***************************************
* CABD_SEARCH, CABD_FIND
***************************************
* cabd_search opens a file, finds its extent, allocates a search buffer,
* then reads through the whole file looking for possible cabinet headers.
* if it finds any, it tries to read them as real cabinets. returns a linked
* list of results
*
* cabd_find is the inner loop of cabd_search, to make it easier to
* break out of the loop and be sure that all resources are freed
*/
static struct mscabd_cabinet *cabd_search(struct mscab_decompressor *base,
char *filename)
{
struct mscab_decompressor_p *this = (struct mscab_decompressor_p *) base;
struct mscabd_cabinet_p *cab = NULL;
struct mspack_system *sys;
unsigned char *search_buf;
struct mspack_file *fh;
unsigned int firstlen = 0;
off_t filelen;
if (!base) return NULL;
sys = this->system;
/* allocate a search buffer */
search_buf = sys->alloc(sys, (size_t) this->param[MSCABD_PARAM_SEARCHBUF]);
if (!search_buf) {
this->error = MSPACK_ERR_NOMEMORY;
return NULL;
}
/* open file and get its full file length */
if ((fh = sys->open(sys, filename, MSPACK_SYS_OPEN_READ))) {
if (!(this->error = mspack_sys_filelen(sys, fh, &filelen))) {
this->error = cabd_find(this, search_buf, fh, filename, 0,
filelen, &firstlen, &cab);
}
/* truncated / extraneous data warning: */
if (firstlen && (firstlen != filelen) &&
(!cab || (cab->base.base_offset == 0)))
{
if (firstlen < filelen) {
sys->message(fh, "WARNING; possible %u extra bytes at end of file.",
(unsigned int) (filelen - firstlen));
}
else {
sys->message(fh, "WARNING; file possibly truncated by %u bytes.",
(unsigned int) (firstlen - filelen));
}
}
sys->close(fh);
}
else {
this->error = MSPACK_ERR_OPEN;
}
/* free the search buffer */
sys->free(search_buf);
return (struct mscabd_cabinet *) cab;
}
static struct mscabd_cabinet *cabd_dsearch(struct mscab_decompressor *base,
int desc)
{
struct mscab_decompressor_p *this = (struct mscab_decompressor_p *) base;
struct mscabd_cabinet_p *cab = NULL;
struct mspack_system *sys;
unsigned char *search_buf;
struct mspack_file *fh;
unsigned int firstlen = 0;
off_t filelen; |
| dc2e0dc7 |
}
else {
this->error = MSPACK_ERR_OPEN;
}
/* free the search buffer */
sys->free(search_buf);
return (struct mscabd_cabinet *) cab;
}
static int cabd_find(struct mscab_decompressor_p *this, unsigned char *buf,
struct mspack_file *fh, char *filename, int desc, off_t flen,
unsigned int *firstlen,
struct mscabd_cabinet_p **firstcab)
{
struct mscabd_cabinet_p *cab, *link = NULL;
off_t caboff, offset, foffset=0, cablen=0;
struct mspack_system *sys = this->system;
unsigned char *p, *pend, state = 0;
int false_cabs = 0, length;
/* search through the full file length */
for (offset = 0; offset < flen; offset += length) {
/* search length is either the full length of the search buffer, or the
* amount of data remaining to the end of the file, whichever is less. */
length = flen - offset;
if (length > this->param[MSCABD_PARAM_SEARCHBUF]) {
length = this->param[MSCABD_PARAM_SEARCHBUF];
}
/* fill the search buffer with data from disk */
if (sys->read(fh, &buf[0], length) != length) {
return MSPACK_ERR_READ;
}
/* FAQ avoidance strategy */
if ((offset == 0) && (EndGetI32(&buf[0]) == 0x28635349)) {
sys->message(fh, "WARNING; found InstallShield header. "
"This is probably an InstallShield file. "
"Use UNSHIELD (http://synce.sf.net) to unpack it.");
}
/* read through the entire buffer. */
for (p = &buf[0], pend = &buf[length]; p < pend; ) {
switch (state) {
/* starting state */
case 0:
/* we spend most of our time in this while loop, looking for
* a leading 'M' of the 'MSCF' signature */
while (p < pend && *p != 0x4D) p++;
/* if we found tht 'M', advance state */
if (p++ < pend) state = 1;
break;
/* verify that the next 3 bytes are 'S', 'C' and 'F' */
case 1: state = (*p++ == 0x53) ? 2 : 0; break;
case 2: state = (*p++ == 0x43) ? 3 : 0; break;
case 3: state = (*p++ == 0x46) ? 4 : 0; break;
/* we don't care about bytes 4-7 (see default: for action) */
/* bytes 8-11 are the overall length of the cabinet */
case 8: cablen = *p++; state++; break;
case 9: cablen |= *p++ << 8; state++; break;
case 10: cablen |= *p++ << 16; state++; break;
case 11: cablen |= *p++ << 24; state++; break;
/* we don't care about bytes 12-15 (see default: for action) */
/* bytes 16-19 are the offset within the cabinet of the filedata */
case 16: foffset = *p++; state++; break;
case 17: foffset |= *p++ << 8; state++; break;
case 18: foffset |= *p++ << 16; state++; break;
case 19: foffset |= *p++ << 24;
/* now we have recieved 20 bytes of potential cab header. work out
* the offset in the file of this potential cabinet */
caboff = offset + (p - &buf[0]) - 20;
/* should reading cabinet fail, restart search just after 'MSCF' */
offset = caboff + 4;
/* capture the "length of cabinet" field if there is a cabinet at
* offset 0 in the file, regardless of whether the cabinet can be
* read correctly or not */
if (caboff == 0) *firstlen = cablen;
/* check that the files offset is less than the alleged length of
* the cabinet, and that the offset + the alleged length are
* 'roughly' within the end of overall file length */
if ((foffset < cablen) &&
((caboff + foffset) < (flen + 32)) &&
((caboff + cablen) < (flen + 32)) )
{
/* likely cabinet found -- try reading it */
if (!(cab = sys->alloc(sys, sizeof(struct mscabd_cabinet_p)))) {
return MSPACK_ERR_NOMEMORY;
}
cab->base.filename = filename; |
| dc2e0dc7 |
if (cabd_read_headers(sys, fh, cab, caboff, 1)) {
/* destroy the failed cabinet */
cabd_close((struct mscab_decompressor *) this,
(struct mscabd_cabinet *) cab);
false_cabs++;
}
else {
/* cabinet read correctly! */
/* cause the search to restart after this cab's data. */
offset = caboff + cablen;
/* link the cab into the list */
if (!link) *firstcab = cab;
else link->base.next = (struct mscabd_cabinet *) cab;
link = cab;
}
}
/* restart search */
if (offset >= flen) return MSPACK_ERR_OK;
if (sys->seek(fh, offset, MSPACK_SYS_SEEK_START))
return MSPACK_ERR_SEEK;
length = 0;
p = pend;
state = 0;
break;
/* for bytes 4-7 and 12-15, just advance state/pointer */
default:
p++, state++;
} /* switch(state) */
} /* for (... p < pend ...) */
} /* for (... offset < length ...) */
if (false_cabs) {
D(("%d false cabinets found", false_cabs))
}
return MSPACK_ERR_OK;
}
/***************************************
* CABD_MERGE, CABD_PREPEND, CABD_APPEND
***************************************
* joins cabinets together, also merges split folders between these two
* cabinets only. this includes freeing the duplicate folder and file(s)
* and allocating a further mscabd_folder_data structure to append to the
* merged folder's data parts list.
*/
static int cabd_prepend(struct mscab_decompressor *base,
struct mscabd_cabinet *cab,
struct mscabd_cabinet *prevcab)
{
return cabd_merge(base, prevcab, cab);
}
static int cabd_append(struct mscab_decompressor *base,
struct mscabd_cabinet *cab,
struct mscabd_cabinet *nextcab)
{
return cabd_merge(base, cab, nextcab);
}
static int cabd_merge(struct mscab_decompressor *base,
struct mscabd_cabinet *lcab,
struct mscabd_cabinet *rcab)
{
struct mscab_decompressor_p *this = (struct mscab_decompressor_p *) base;
struct mscabd_folder_data *data, *ndata;
struct mscabd_folder_p *lfol, *rfol;
struct mscabd_file *fi, *rfi, *lfi;
struct mscabd_cabinet *cab;
struct mspack_system *sys;
if (!this) return MSPACK_ERR_ARGS;
sys = this->system;
/* basic args check */
if (!lcab || !rcab || (lcab == rcab)) {
D(("lcab NULL, rcab NULL or lcab = rcab"))
return this->error = MSPACK_ERR_ARGS;
}
/* check there's not already a cabinet attached */
if (lcab->nextcab || rcab->prevcab) {
D(("cabs already joined"))
return this->error = MSPACK_ERR_ARGS;
}
/* do not create circular cabinet chains */
for (cab = lcab->prevcab; cab; cab = cab->prevcab) {
if (cab == rcab) {D(("circular!")) return this->error = MSPACK_ERR_ARGS;}
}
for (cab = rcab->nextcab; cab; cab = cab->nextcab) {
if (cab == lcab) {D(("circular!")) return this->error = MSPACK_ERR_ARGS;}
}
/* warn about odd set IDs or indices */
if (lcab->set_id != rcab->set_id) {
sys->message(NULL, "WARNING; merged cabinets with differing Set IDs.");
}
if (lcab->set_index > rcab->set_index) {
sys->message(NULL, "WARNING; merged cabinets with odd order.");
}
/* merging the last folder in lcab with the first folder in rcab */
lfol = (struct mscabd_folder_p *) lcab->folders;
rfol = (struct mscabd_folder_p *) rcab->folders;
while (lfol->base.next) lfol = (struct mscabd_folder_p *) lfol->base.next;
/* do we need to merge folders? */
if (!lfol->merge_next && !rfol->merge_prev) {
/* no, at least one of the folders is not for merging */
/* attach cabs */
lcab->nextcab = rcab;
rcab->prevcab = lcab;
/* attach folders */
lfol->base.next = (struct mscabd_folder *) rfol;
/* attach files */
fi = lcab->files;
while (fi->next) fi = fi->next;
fi->next = rcab->files;
}
else {
/* folder merge required */
if (!lfol->merge_next) {
D(("rcab has merge files, lcab doesn't"))
return this->error = MSPACK_ERR_DATAFORMAT;
}
if (!rfol->merge_prev) {
D(("lcab has merge files, rcab doesn't"))
return this->error = MSPACK_ERR_DATAFORMAT;
}
/* check that both folders use the same compression method/settings */
if (lfol->base.comp_type != rfol->base.comp_type) {
D(("compression type mismatch"))
return this->error = MSPACK_ERR_DATAFORMAT;
}
/* for all files in lfol (which is the last folder in whichever cab),
* compare them to the files from rfol. they should be identical in
* number and order. to verify this, check the OFFSETS of each file. */
lfi = lfol->merge_next;
rfi = rfol->merge_prev;
while (lfi) {
if (!rfi || (lfi->offset != rfi->offset)) {
D(("folder merge mismatch"))
return this->error = MSPACK_ERR_DATAFORMAT;
}
lfi = lfi->next;
rfi = rfi->next;
}
/* allocate a new folder data structure */
if (!(data = sys->alloc(sys, sizeof(struct mscabd_folder_data)))) {
return this->error = MSPACK_ERR_NOMEMORY;
}
/* attach cabs */
lcab->nextcab = rcab;
rcab->prevcab = lcab;
/* append rfol's data to lfol */
ndata = &lfol->data;
while (ndata->next) ndata = ndata->next;
ndata->next = data;
*data = rfol->data;
rfol->data.next = NULL;
/* lfol becomes rfol.
* NOTE: special case, don't merge if rfol is merge prev and next,
* rfol->merge_next is going to be deleted, so keep lfol's version
* instead */
lfol->base.num_blocks += rfol->base.num_blocks - 1;
if ((rfol->merge_next == NULL) ||
(rfol->merge_next->folder != (struct mscabd_folder *) rfol))
{
lfol->merge_next = rfol->merge_next;
}
/* attach the rfol's folder (except the merge folder) */
while (lfol->base.next) lfol = (struct mscabd_folder_p *) lfol->base.next;
lfol->base.next = rfol->base.next;
/* free disused merge folder */
sys->free(rfol);
/* attach rfol's files */
fi = lcab->files;
while (fi->next) fi = fi->next;
fi->next = rcab->files;
/* delete all files from rfol's merge folder */
lfi = NULL;
for (fi = lcab->files; fi ; fi = rfi) {
rfi = fi->next;
/* if file's folder matches the merge folder, unlink and free it */
if (fi->folder == (struct mscabd_folder *) rfol) {
if (lfi) lfi->next = rfi; else lcab->files = rfi;
sys->free(fi->filename);
sys->free(fi);
}
else lfi = fi;
}
}
/* all done! fix files and folders pointers in all cabs so they all
* point to the same list */
for (cab = lcab->prevcab; cab; cab = cab->prevcab) {
cab->files = lcab->files;
cab->folders = lcab->folders;
}
for (cab = lcab->nextcab; cab; cab = cab->nextcab) {
cab->files = lcab->files;
cab->folders = lcab->folders;
}
return this->error = MSPACK_ERR_OK;
}
/***************************************
* CABD_EXTRACT
***************************************
* extracts a file from a cabinet
*/
static int cabd_extract(struct mscab_decompressor *base,
struct mscabd_file *file, char *filename)
{
struct mscab_decompressor_p *this = (struct mscab_decompressor_p *) base;
struct mscabd_folder_p *fol;
struct mspack_system *sys;
struct mspack_file *fh;
if (!this) return MSPACK_ERR_ARGS;
if (!file) return this->error = MSPACK_ERR_ARGS;
sys = this->system;
fol = (struct mscabd_folder_p *) file->folder;
/* check if file can be extracted */
if ((!fol) || (fol->merge_prev) ||
(((file->offset + file->length) / CAB_BLOCKMAX) > fol->base.num_blocks))
{
sys->message(NULL, "ERROR; file \"%s\" cannot be extracted, "
"cabinet set is incomplete.", file->filename);
return this->error = MSPACK_ERR_DATAFORMAT;
}
/* allocate generic decompression state */
if (!this->d) {
this->d = sys->alloc(sys, sizeof(struct mscabd_decompress_state));
if (!this->d) return this->error = MSPACK_ERR_NOMEMORY;
this->d->folder = NULL;
this->d->data = NULL;
this->d->sys = *sys;
this->d->sys.read = &cabd_sys_read;
this->d->sys.write = &cabd_sys_write;
this->d->state = NULL;
this->d->infh = NULL;
this->d->incab = NULL;
}
/* do we need to change folder or reset the current folder? */
if ((this->d->folder != fol) || (this->d->offset > file->offset)) {
/* do we need to open a new cab file? */
if (!this->d->infh || (fol->data.cab != this->d->incab)) {
if (this->d->infh) sys->close(this->d->infh);
this->d->incab = fol->data.cab;
if(fol->data.cab->base.desc) {
this->d->infh = sys->dopen(sys, fol->data.cab->base.desc,
MSPACK_SYS_OPEN_READ);
} else {
this->d->infh = sys->open(sys, fol->data.cab->base.filename,
MSPACK_SYS_OPEN_READ);
}
if (!this->d->infh) return this->error = MSPACK_ERR_OPEN;
}
/* seek to start of data blocks */
if (sys->seek(this->d->infh, fol->data.offset, MSPACK_SYS_SEEK_START)) {
return this->error = MSPACK_ERR_SEEK;
}
/* set up decompressor */
if (cabd_init_decomp(this, (unsigned int) fol->base.comp_type)) {
return this->error;
}
/* initialise new folder state */
this->d->folder = fol;
this->d->data = &fol->data;
this->d->offset = 0;
this->d->block = 0;
this->d->i_ptr = this->d->i_end = &this->d->input[0];
}
/* open file for output */
if (!(fh = sys->open(sys, filename, MSPACK_SYS_OPEN_WRITE))) {
return this->error = MSPACK_ERR_OPEN;
}
this->error = MSPACK_ERR_OK;
/* if file has more than 0 bytes */
if (file->length) {
off_t bytes;
int error;
/* get to correct offset.
* - use NULL fh to say 'no writing' to cabd_sys_write()
* - MSPACK_ERR_READ returncode indicates error in cabd_sys_read(),
* the real error will already be stored in this->error
*/
this->d->outfh = NULL;
if ((bytes = file->offset - this->d->offset)) {
error = this->d->decompress(this->d->state, bytes);
if (error != MSPACK_ERR_READ) this->error = error;
}
/* if getting to the correct offset was error free, unpack file */
if (!this->error) {
this->d->outfh = fh;
error = this->d->decompress(this->d->state, (off_t) file->length);
if (error != MSPACK_ERR_READ) this->error = error;
}
}
/* close output file */
sys->close(fh);
this->d->outfh = NULL;
return this->error;
}
/***************************************
* CABD_INIT_DECOMP, CABD_FREE_DECOMP
***************************************
* cabd_init_decomp initialises decompression state, according to which
* decompression method was used. relies on this->d->folder being the same
* as when initialised.
*
* cabd_free_decomp frees decompression state, according to which method
* was used.
*/
static int cabd_init_decomp(struct mscab_decompressor_p *this, unsigned int ct)
{
struct mspack_file *fh = (struct mspack_file *) this;
if (!this || !this->d) {
return this->error = MSPACK_ERR_ARGS;
}
/* free any existing decompressor */
cabd_free_decomp(this);
this->d->comp_type = ct;
switch (ct & cffoldCOMPTYPE_MASK) {
case cffoldCOMPTYPE_NONE:
this->d->decompress = (int (*)(void *, off_t)) &noned_decompress;
this->d->state = noned_init(&this->d->sys, fh, fh,
this->param[MSCABD_PARAM_DECOMPBUF]);
break;
case cffoldCOMPTYPE_MSZIP:
this->d->decompress = (int (*)(void *, off_t)) &mszipd_decompress;
this->d->state = mszipd_init(&this->d->sys, fh, fh,
this->param[MSCABD_PARAM_DECOMPBUF],
this->param[MSCABD_PARAM_FIXMSZIP]);
break;
case cffoldCOMPTYPE_QUANTUM:
this->d->decompress = (int (*)(void *, off_t)) &qtmd_decompress;
this->d->state = qtmd_init(&this->d->sys, fh, fh, (int) (ct >> 8) & 0x1f,
this->param[MSCABD_PARAM_DECOMPBUF]);
break;
case cffoldCOMPTYPE_LZX:
this->d->decompress = (int (*)(void *, off_t)) &lzxd_decompress;
this->d->state = lzxd_init(&this->d->sys, fh, fh, (int) (ct >> 8) & 0x1f, 0,
this->param[MSCABD_PARAM_DECOMPBUF], (off_t) 0);
break;
default:
return this->error = MSPACK_ERR_DATAFORMAT;
}
return this->error = (this->d->state) ? MSPACK_ERR_OK : MSPACK_ERR_NOMEMORY;
}
static void cabd_free_decomp(struct mscab_decompressor_p *this) {
if (!this || !this->d || !this->d->folder || !this->d->state) return;
switch (this->d->comp_type & cffoldCOMPTYPE_MASK) {
case cffoldCOMPTYPE_NONE: noned_free(this->d->state); break;
case cffoldCOMPTYPE_MSZIP: mszipd_free(this->d->state); break;
case cffoldCOMPTYPE_QUANTUM: qtmd_free(this->d->state); break;
case cffoldCOMPTYPE_LZX: lzxd_free(this->d->state); break;
}
this->d->decompress = NULL;
this->d->state = NULL;
}
/***************************************
* CABD_SYS_READ, CABD_SYS_WRITE
***************************************
* cabd_sys_read is the internal reader function which the decompressors
* use. will read data blocks (and merge split blocks) from the cabinet
* and serve the read bytes to the decompressors
*
* cabd_sys_write is the internal writer function which the decompressors
* use. it either writes data to disk (this->d->outfh) with the real
* sys->write() function, or does nothing with the data when
* this->d->outfh == NULL. advances this->d->offset
*/
static int cabd_sys_read(struct mspack_file *file, void *buffer, int bytes) {
struct mscab_decompressor_p *this = (struct mscab_decompressor_p *) file;
unsigned char *buf = (unsigned char *) buffer;
struct mspack_system *sys = this->system;
int avail, todo, outlen, ignore_cksum;
ignore_cksum = this->param[MSCABD_PARAM_FIXMSZIP] &&
((this->d->comp_type & cffoldCOMPTYPE_MASK) == cffoldCOMPTYPE_MSZIP);
todo = bytes;
while (todo > 0) {
avail = this->d->i_end - this->d->i_ptr;
/* if out of input data, read a new block */
if (avail) {
/* copy as many input bytes available as possible */
if (avail > todo) avail = todo;
sys->copy(this->d->i_ptr, buf, (size_t) avail);
this->d->i_ptr += avail;
buf += avail;
todo -= avail;
}
else {
/* out of data, read a new block */
/* check if we're out of input blocks, advance block counter */
if (this->d->block++ >= this->d->folder->base.num_blocks) {
this->error = MSPACK_ERR_DATAFORMAT;
break;
}
/* read a block */
this->error = cabd_sys_read_block(sys, this->d, &outlen, ignore_cksum);
if (this->error) return -1;
/* special Quantum hack -- trailer byte to allow the decompressor
* to realign itself. CAB Quantum blocks, unlike LZX blocks, can have
* anything from 0 to 4 trailing null bytes. */
if ((this->d->comp_type & cffoldCOMPTYPE_MASK)==cffoldCOMPTYPE_QUANTUM) {
*this->d->i_end++ = 0xFF;
}
/* is this the last block? */
if (this->d->block >= this->d->folder->base.num_blocks) {
/* last block */
if ((this->d->comp_type & cffoldCOMPTYPE_MASK) == cffoldCOMPTYPE_LZX) {
/* special LZX hack -- on the last block, inform LZX of the
* size of the output data stream. */
lzxd_set_output_length(this->d->state, (off_t)
((this->d->block-1) * CAB_BLOCKMAX + outlen));
}
}
else {
/* not the last block */
if (outlen != CAB_BLOCKMAX) {
this->system->message(this->d->infh,
"WARNING; non-maximal data block");
}
}
} /* if (avail) */
} /* while (todo > 0) */
return bytes - todo;
}
static int cabd_sys_write(struct mspack_file *file, void *buffer, int bytes) {
struct mscab_decompressor_p *this = (struct mscab_decompressor_p *) file;
this->d->offset += bytes;
if (this->d->outfh) {
return this->system->write(this->d->outfh, buffer, bytes);
}
return bytes;
}
/***************************************
* CABD_SYS_READ_BLOCK
***************************************
* reads a whole data block from a cab file. the block may span more than
* one cab file, if it does then the fragments will be reassembled
*/
static int cabd_sys_read_block(struct mspack_system *sys,
struct mscabd_decompress_state *d,
int *out, int ignore_cksum)
{
unsigned char hdr[cfdata_SIZEOF];
unsigned int cksum;
int len;
/* reset the input block pointer and end of block pointer */
d->i_ptr = d->i_end = &d->input[0];
do {
/* read the block header */
if (sys->read(d->infh, &hdr[0], cfdata_SIZEOF) != cfdata_SIZEOF) {
return MSPACK_ERR_READ;
}
/* skip any reserved block headers */
if (d->data->cab->block_resv &&
sys->seek(d->infh, (off_t) d->data->cab->block_resv,
MSPACK_SYS_SEEK_CUR))
{
return MSPACK_ERR_SEEK;
}
/* blocks must not be over CAB_INPUTMAX in size */
len = EndGetI16(&hdr[cfdata_CompressedSize]);
if (((d->i_end - d->i_ptr) + len) > CAB_INPUTMAX) {
D(("block size > CAB_INPUTMAX (%d + %d)", d->i_end - d->i_ptr, len))
return MSPACK_ERR_DATAFORMAT;
}
/* blocks must not expand to more than CAB_BLOCKMAX */
if (EndGetI16(&hdr[cfdata_UncompressedSize]) > CAB_BLOCKMAX) {
D(("block size > CAB_BLOCKMAX"))
return MSPACK_ERR_DATAFORMAT;
}
/* read the block data */
if (sys->read(d->infh, d->i_end, len) != len) {
return MSPACK_ERR_READ;
}
/* perform checksum test on the block (if one is stored) */
if ((cksum = EndGetI32(&hdr[cfdata_CheckSum]))) {
unsigned int sum2 = cabd_checksum(d->i_end, (unsigned int) len, 0);
if (cabd_checksum(&hdr[4], 4, sum2) != cksum) {
if (!ignore_cksum) return MSPACK_ERR_CHECKSUM;
sys->message(d->infh, "WARNING; bad block checksum found");
}
}
/* advance end of block pointer to include newly read data */
d->i_end += len;
/* uncompressed size == 0 means this block was part of a split block
* and it continues as the first block of the next cabinet in the set.
* otherwise, this is the last part of the block, and no more block
* reading needs to be done.
*/
/* EXIT POINT OF LOOP -- uncompressed size != 0 */
if ((*out = EndGetI16(&hdr[cfdata_UncompressedSize]))) {
return MSPACK_ERR_OK;
}
/* otherwise, advance to next cabinet */
/* close current file handle */
sys->close(d->infh);
d->infh = NULL;
/* advance to next member in the cabinet set */
if (!(d->data = d->data->next)) {
D(("ran out of splits in cabinet set"))
return MSPACK_ERR_DATAFORMAT;
}
/* open next cab file */
d->incab = d->data->cab;
if (!(d->infh = sys->open(sys, d->incab->base.filename,
MSPACK_SYS_OPEN_READ)))
{
return MSPACK_ERR_OPEN;
}
/* seek to start of data blocks */
if (sys->seek(d->infh, d->data->offset, MSPACK_SYS_SEEK_START)) {
return MSPACK_ERR_SEEK;
}
} while (1);
/* not reached */
return MSPACK_ERR_OK;
}
static unsigned int cabd_checksum(unsigned char *data, unsigned int bytes,
unsigned int cksum)
{
unsigned int len, ul = 0;
for (len = bytes >> 2; len--; data += 4) {
cksum ^= ((data[0]) | (data[1]<<8) | (data[2]<<16) | (data[3]<<24));
}
switch (bytes & 3) {
case 3: ul |= *data++ << 16;
case 2: ul |= *data++ << 8;
case 1: ul |= *data;
}
cksum ^= ul;
return cksum;
}
/***************************************
* NONED_INIT, NONED_DECOMPRESS, NONED_FREE
***************************************
* the "not compressed" method decompressor
*/
struct noned_state {
struct mspack_system *sys;
struct mspack_file *i;
struct mspack_file *o;
unsigned char *buf;
int bufsize;
};
static struct noned_state *noned_init(struct mspack_system *sys,
struct mspack_file *in,
struct mspack_file *out,
int bufsize)
{
struct noned_state *state = sys->alloc(sys, sizeof(struct noned_state));
unsigned char *buf = sys->alloc(sys, (size_t) bufsize);
if (state && buf) {
state->sys = sys;
state->i = in;
state->o = out;
state->buf = buf;
state->bufsize = bufsize;
}
else {
sys->free(buf);
sys->free(state);
state = NULL;
}
return state;
}
static int noned_decompress(struct noned_state *s, off_t bytes) {
int run;
while (bytes > 0) {
run = (bytes > s->bufsize) ? s->bufsize : (int) bytes;
if (s->sys->read(s->i, &s->buf[0], run) != run) return MSPACK_ERR_READ;
if (s->sys->write(s->o, &s->buf[0], run) != run) return MSPACK_ERR_WRITE;
bytes -= run;
}
return MSPACK_ERR_OK;
}
static void noned_free(struct noned_state *state) {
struct mspack_system *sys;
if (state) {
sys = state->sys;
sys->free(state->buf);
sys->free(state);
}
}
/***************************************
* CABD_PARAM
***************************************
* allows a parameter to be set
*/
static int cabd_param(struct mscab_decompressor *base, int param, int value) {
struct mscab_decompressor_p *this = (struct mscab_decompressor_p *) base;
if (!this) return MSPACK_ERR_ARGS;
switch (param) {
case MSCABD_PARAM_SEARCHBUF:
if (value < 4) return MSPACK_ERR_ARGS;
this->param[MSCABD_PARAM_SEARCHBUF] = value;
break;
case MSCABD_PARAM_FIXMSZIP:
this->param[MSCABD_PARAM_FIXMSZIP] = value;
break;
case MSCABD_PARAM_DECOMPBUF:
if (value < 4) return MSPACK_ERR_ARGS;
this->param[MSCABD_PARAM_DECOMPBUF] = value;
break;
default:
return MSPACK_ERR_ARGS;
}
return MSPACK_ERR_OK;
}
/***************************************
* CABD_ERROR
***************************************
* returns the last error that occurred
*/
static int cabd_error(struct mscab_decompressor *base) {
struct mscab_decompressor_p *this = (struct mscab_decompressor_p *) base;
return (this) ? this->error : MSPACK_ERR_ARGS;
} |