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/*
* Copyright 2003-2021 The Music Player Daemon Project
* http://www.musicpd.org
*
* 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 2 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, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
/**
* iso archive handling (requires cdio, and iso9660)
*/
#include "Iso9660ArchivePlugin.hxx"
#include "../ArchivePlugin.hxx"
#include "../ArchiveFile.hxx"
#include "../ArchiveVisitor.hxx"
#include "input/InputStream.hxx"
#include "fs/Path.hxx"
#include "util/RuntimeError.hxx"
#include "util/StringCompare.hxx"
#include "util/WritableBuffer.hxx"
#include <cdio/iso9660.h>
#include <array>
#include <utility>
#include <stdlib.h>
#include <string.h>
struct Iso9660 {
iso9660_t *const iso;
explicit Iso9660(Path path)
:iso(iso9660_open(path.c_str())) {
if (iso == nullptr)
throw FormatRuntimeError("Failed to open ISO9660 file %s",
path.c_str());
}
~Iso9660() noexcept {
iso9660_close(iso);
}
Iso9660(const Iso9660 &) = delete;
Iso9660 &operator=(const Iso9660 &) = delete;
long SeekRead(void *ptr, lsn_t start, long int i_size) const {
return iso9660_iso_seek_read(iso, ptr, start, i_size);
}
};
class Iso9660ArchiveFile final : public ArchiveFile {
std::shared_ptr<Iso9660> iso;
public:
explicit Iso9660ArchiveFile(std::shared_ptr<Iso9660> &&_iso)
:iso(std::move(_iso)) {}
/**
* @param capacity the path buffer size
*/
void Visit(char *path, size_t length, size_t capacity,
ArchiveVisitor &visitor);
void Visit(ArchiveVisitor &visitor) override;
InputStreamPtr OpenStream(const char *path,
Mutex &mutex) override;
};
/* archive open && listing routine */
inline void
Iso9660ArchiveFile::Visit(char *path, size_t length, size_t capacity,
ArchiveVisitor &visitor)
{
auto *entlist = iso9660_ifs_readdir(iso->iso, path);
if (!entlist) {
return;
}
/* Iterate over the list of nodes that iso9660_ifs_readdir gives */
CdioListNode_t *entnode;
_CDIO_LIST_FOREACH (entnode, entlist) {
auto *statbuf = (iso9660_stat_t *)
_cdio_list_node_data(entnode);
const char *filename = statbuf->filename;
if (StringIsEmpty(filename) ||
PathTraitsUTF8::IsSpecialFilename(filename))
/* skip empty names (libcdio bug?) */
/* skip special names like "." and ".." */
continue;
size_t filename_length = strlen(filename);
if (length + filename_length + 1 >= capacity)
/* file name is too long */
continue;
memcpy(path + length, filename, filename_length + 1);
size_t new_length = length + filename_length;
if (iso9660_stat_s::_STAT_DIR == statbuf->type ) {
memcpy(path + new_length, "/", 2);
Visit(path, new_length + 1, capacity, visitor);
} else {
//remove leading /
visitor.VisitArchiveEntry(path + 1);
}
}
#if LIBCDIO_VERSION_NUM >= 20000
iso9660_filelist_free(entlist);
#else
_cdio_list_free (entlist, true);
#endif
}
static std::unique_ptr<ArchiveFile>
iso9660_archive_open(Path pathname)
{
return std::make_unique<Iso9660ArchiveFile>(std::make_shared<Iso9660>(pathname));
}
void
Iso9660ArchiveFile::Visit(ArchiveVisitor &visitor)
{
char path[4096] = "/";
Visit(path, 1, sizeof(path), visitor);
}
/* single archive handling */
class Iso9660InputStream final : public InputStream {
std::shared_ptr<Iso9660> iso;
const lsn_t lsn;
/**
* libiso9660 can only read whole sectors at a time, and this
* buffer is used to store one whole sector and allow Read()
* to handle partial sector reads.
*/
class BlockBuffer {
size_t position = 0, fill = 0;
std::array<uint8_t, ISO_BLOCKSIZE> data;
public:
ConstBuffer<uint8_t> Read() const noexcept {
assert(fill <= data.size());
assert(position <= fill);
return {&data[position], &data[fill]};
}
void Consume(size_t nbytes) noexcept {
assert(nbytes <= Read().size);
position += nbytes;
}
WritableBuffer<uint8_t> Write() noexcept {
assert(Read().empty());
return {data.data(), data.size()};
}
void Append(size_t nbytes) noexcept {
assert(Read().empty());
assert(nbytes <= data.size());
fill = nbytes;
position = 0;
}
void Clear() noexcept {
position = fill = 0;
}
};
BlockBuffer buffer;
/**
* Skip this number of bytes of the first sector after filling
* the buffer next time. This is used for seeking into the
* middle of a sector.
*/
size_t skip = 0;
public:
Iso9660InputStream(std::shared_ptr<Iso9660> _iso,
const char *_uri,
Mutex &_mutex,
lsn_t _lsn, offset_type _size)
:InputStream(_uri, _mutex),
iso(std::move(_iso)),
lsn(_lsn)
{
size = _size;
seekable = true;
SetReady();
}
/* virtual methods from InputStream */
[[nodiscard]] bool IsEOF() const noexcept override;
size_t Read(std::unique_lock<Mutex> &lock,
void *ptr, size_t size) override;
void Seek(std::unique_lock<Mutex> &, offset_type new_offset) override {
if (new_offset > size)
throw std::runtime_error("Invalid seek offset");
offset = new_offset;
skip = new_offset % ISO_BLOCKSIZE;
buffer.Clear();
}
};
InputStreamPtr
Iso9660ArchiveFile::OpenStream(const char *pathname,
Mutex &mutex)
{
auto statbuf = iso9660_ifs_stat_translate(iso->iso, pathname);
if (statbuf == nullptr)
throw FormatRuntimeError("not found in the ISO file: %s",
pathname);
const lsn_t lsn = statbuf->lsn;
const offset_type size = statbuf->size;
free(statbuf);
return std::make_unique<Iso9660InputStream>(iso, pathname, mutex,
lsn, size);
}
size_t
Iso9660InputStream::Read(std::unique_lock<Mutex> &,
void *ptr, size_t read_size)
{
const offset_type remaining = size - offset;
if (remaining == 0)
return 0;
if (offset_type(read_size) > remaining)
read_size = remaining;
auto r = buffer.Read();
if (r.empty()) {
/* the buffer is empty - read more data from the ISO file */
assert((offset - skip) % ISO_BLOCKSIZE == 0);
const ScopeUnlock unlock(mutex);
const lsn_t read_lsn = lsn + offset / ISO_BLOCKSIZE;
if (read_size >= ISO_BLOCKSIZE && skip == 0) {
/* big read - read right into the caller's buffer */
auto nbytes = iso->SeekRead(ptr, read_lsn,
read_size / ISO_BLOCKSIZE);
if (nbytes <= 0)
throw std::runtime_error("Failed to read ISO9660 file");
offset += nbytes;
return nbytes;
}
/* fill the buffer */
auto w = buffer.Write();
auto nbytes = iso->SeekRead(w.data, read_lsn,
w.size / ISO_BLOCKSIZE);
if (nbytes <= 0)
throw std::runtime_error("Failed to read ISO9660 file");
buffer.Append(nbytes);
r = buffer.Read();
if (skip > 0) {
if (skip >= r.size)
throw std::runtime_error("Premature end of ISO9660 track");
buffer.Consume(skip);
skip = 0;
r = buffer.Read();
}
}
assert(!r.empty());
assert(skip == 0);
size_t nbytes = std::min(read_size, r.size);
memcpy(ptr, r.data, nbytes);
buffer.Consume(nbytes);
offset += nbytes;
return nbytes;
}
bool
Iso9660InputStream::IsEOF() const noexcept
{
return offset == size;
}
/* exported structures */
static const char *const iso9660_archive_extensions[] = {
"iso",
nullptr
};
const ArchivePlugin iso9660_archive_plugin = {
"iso",
nullptr,
nullptr,
iso9660_archive_open,
iso9660_archive_extensions,
};
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