iffexplore: Put IFF parsing logic in own class

Created an IffFile class which contains the IFF parsing logic, changed
iffexplore to use this class.
This commit is contained in:
2015-04-22 17:18:43 +02:00
parent f46521259c
commit c87836468d
4 changed files with 424 additions and 147 deletions

137
IffFile.cc Normal file
View File

@@ -0,0 +1,137 @@
#include <arpa/inet.h>
#include "IffFile.hh"
#include "common.hh"
struct ChunkHeader {
char typeID[4];
uint32_t length; // big endian!!
} __attribute__((__packed__));
IffFile::IffFile(char const* base, size_t length)
: base_(base), length_(length), root_(nullptr)
{
root_ = parseObject(base, length);
#ifndef NDEBUG
if (length > (root_->getSize()+8)) {
printf("%lu excess bytes parsing IFF\n", length-(root_->getSize()+8));
}
#endif
}
IffFile::~IffFile()
{
}
static void _printStructure(IffFile::Object const& obj, unsigned level)
{
for (unsigned i = 0;i < level;++i)
putchar('\t');
printf("%s Length %lu (0x%.lx)", obj.getType().c_str(), obj.getSize(), obj.getSize());
if (obj.isForm()) {
auto form = dynamic_cast<IffFile::Form const&>(obj);
printf(", Subtype %s\n", form.getSubtype().c_str());
for(auto it = form.childrenBegin();it != form.childrenEnd();++it)
_printStructure(*it, level+1);
} else {
try {
printf(" = \"%s\"\n", static_cast<std::string>(obj).c_str());
} catch(FormatException &ex) {
printf("\n");
}
}
}
void IffFile::printStructure(unsigned level)
{
_printStructure(*root_, level);
}
std::unique_ptr<IffFile::Object> IffFile::parseObject(char const* base, size_t length)
{
// if (reinterpret_cast<uintptr_t>(base)%2 != 0) {
// ++base;
// --length;
// }
if (length < sizeof(ChunkHeader))
throw FormatException{"length < header size"};
ChunkHeader header;
memcpy(&header, base, sizeof(ChunkHeader));
header.length = ntohl(header.length);
for (unsigned i = 0;i < 4;++i)
if (!isprint(header.typeID[i]))
throw FormatException{"Not an IFF chunk"};
if (header.length > length-7)
throw FormatException{"length < size in header"};
if(memcmp(header.typeID, "FORM", 4) == 0)
return std::make_unique<Form>("FORM", base+8, static_cast<size_t>(header.length));
else
return std::make_unique<Object>(std::string(header.typeID, 4), base+8, static_cast<size_t>(header.length));
}
IffFile::Object::Object(std::string type, char const* base, size_t length)
: base_(base), length_(length), type_(std::move(type))
{
}
IffFile::Object::operator std::string() const
{
// Check if BLOB is string
enum class State { STARTASCII, NULLS, ERROR };
State state = State::STARTASCII;
for (char const& c : *this) {
switch(state) {
case State::STARTASCII:
if (isprint(c))
continue;
if (c == '\0')
state = State::NULLS;
else
state = State::ERROR;
break;
case State::NULLS:
if (c != '\0')
state = State::ERROR;
break;
case State::ERROR:
break;
}
if (state == State::ERROR)
break;
}
if (state == State::NULLS)
return std::string(base_);
else if (state == State::STARTASCII)
return std::string(base_, length_);
else
throw FormatException{"BLOB not string"};
}
IffFile::Form::Form(std::string type, char const* base, size_t length)
: Object(std::move(type), base, length)
{
if (length < 4)
throw FormatException{"length < subtype id length"};
subtype_ = std::string(base, 4);
size_t pos = 4;
while (pos+8 < length) {
children_.push_back(parseObject(base+pos, length-pos));
pos += 8 + children_.back()->getSize();
if (pos%2 != 0)
++pos;
}
}

200
IffFile.hh Normal file
View File

@@ -0,0 +1,200 @@
#ifndef WC3RE_IFFFILE_HH__
#define WC3RE_IFFFILE_HH__
#include <cstddef>
#include <string>
#include <vector>
#include <memory>
#include <typeinfo>
class IffFile {
public:
IffFile(char const* base, size_t length);
~IffFile();
class Object {
public:
Object(std::string type, char const* base, size_t length);
Object(Object const& copy)
: base_(copy.base_), length_(copy.length_), type_(copy.type_) {
}
virtual ~Object() {
}
virtual Object* copy() const {
return new Object(*this);
}
std::string const& getType() const {
return type_;
}
bool isForm() const {
return (typeid(*this) == typeid(Form));
}
size_t getSize() const {
return length_;
}
char const* begin() const {
return base_;
}
char const* end() const {
return base_+length_;
}
operator std::string() const;
protected:
char const* base_;
const size_t length_;
std::string const type_;
};
class Form final : public Object {
public:
Form(std::string type, char const* base, size_t length);
Form(Form const& copy)
: Object(copy), subtype_(copy.subtype_) {
for(auto& ent : copy.children_) {
children_.push_back(std::unique_ptr<Object>(ent->copy()));
}
}
Form* copy() const override {
return new Form(*this);
}
~Form() {}
std::string const& getSubtype() const {
return subtype_;
}
size_t getChildCount() const {
return children_.size();
}
class ObjectIterator : public std::iterator<std::random_access_iterator_tag, const Object> {
public:
Object const& operator*() const {
return **implIt_;
}
ObjectIterator& operator++() {
++implIt_;
return *this;
}
ObjectIterator& operator--() {
--implIt_;
return *this;
}
bool operator!=(ObjectIterator const& other) const {
return (implIt_ != other.implIt_);
}
bool operator>(ObjectIterator const& other) const {
return (implIt_ > other.implIt_);
}
bool operator>=(ObjectIterator const& other) const {
return (implIt_ >= other.implIt_);
}
bool operator<(ObjectIterator const& other) const {
return (implIt_ < other.implIt_);
}
bool operator<=(ObjectIterator const& other) const {
return (implIt_ <= other.implIt_);
}
Object const* operator->() const {
return implIt_->get();
}
ObjectIterator operator++(int) {
ObjectIterator ret = *this;
++implIt_;
return ret;
}
ObjectIterator operator--(int) {
ObjectIterator ret = *this;
--implIt_;
return ret;
}
ObjectIterator& operator+=(ptrdiff_t n) {
implIt_ += n;
return *this;
}
ObjectIterator operator+(ptrdiff_t n) const {
ObjectIterator ret = *this;
ret += n;
return ret;
}
ObjectIterator& operator-=(ptrdiff_t n) {
implIt_ -= n;
return *this;
}
ObjectIterator operator-(ptrdiff_t n) const {
ObjectIterator ret = *this;
ret -= n;
return ret;
}
ptrdiff_t operator-(ObjectIterator const& other) const {
return implIt_ - other.implIt_;
}
Object const& operator[](ptrdiff_t n) const {
return *(implIt_[n]);
}
private:
ObjectIterator(std::vector<std::unique_ptr<Object> >::const_iterator implIt)
: implIt_(std::move(implIt)) {
}
friend class Form;
std::vector<std::unique_ptr<Object> >::const_iterator implIt_;
};
ObjectIterator childrenBegin() const {
return ObjectIterator(children_.cbegin());
}
ObjectIterator childrenEnd() const {
return ObjectIterator(children_.cend());
}
private:
std::vector<std::unique_ptr<Object> > children_;
std::string subtype_;
};
Object const& getRoot() {
return *root_;
}
void printStructure(unsigned level = 0);
private:
static std::unique_ptr<Object> parseObject(char const* base, size_t length);
char const* base_;
const size_t length_;
std::unique_ptr<Object> root_;
};
#endif

View File

@@ -2,7 +2,7 @@ CXX=g++
CXXOPTS=-Og -ggdb -Wall -Wextra -pedantic -std=c++14 -flto
LDOPTS=
IFFEXPLORE_CXXSRCS=iffexplore.cc
IFFEXPLORE_CXXSRCS=iffexplore.cc IffFile.cc
IFFEXPLORE_OBJS=$(addprefix objs/,$(IFFEXPLORE_CXXSRCS:.cc=.o))
TREEXPLORE_CXXSRCS=treexplore.cc TreFile.cc

View File

@@ -8,176 +8,116 @@
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <sys/mman.h>
#include "common.hh"
#include "IffFile.hh"
struct ChunkHeader {
char typeID[4];
uint32_t length; // big endian!!
} __attribute__((__packed__));
void parseBlob(FILE *iffFile, off_t start, off_t length, char name[4], unsigned level, bool dump = false)
void blobDump(IffFile::Object const& obj, std::string const& filename)
{
static unsigned count = 0;
if (fseeko(iffFile, start, SEEK_SET) != 0) {
throw POSIXException(errno, "Could not seek");
}
FILEUPtr file{fopen(filename.c_str(), "wb")};
if (!file)
throw POSIXException{errno, "Could not open file: " + filename};
std::vector<char> buf(length);
if (fread(buf.data(), length, 1, iffFile) != 1)
throw POSIXException{errno, "Could not read data"};
// Check if BLOB is string
{
enum class State { STARTASCII, NULLS, ERROR };
State state = State::STARTASCII;
for (char const& c : buf) {
switch(state) {
case State::STARTASCII:
if (isprint(c))
continue;
if (c == '\0')
state = State::NULLS;
else
state = State::ERROR;
break;
case State::NULLS:
if (c != '\0')
state = State::ERROR;
break;
case State::ERROR:
break;
}
if (state == State::ERROR)
break;
}
if (state == State::NULLS) { // BLOB is zero(s)-terminated string
for (unsigned i = 0;i < level;++i)
putchar('\t');
printf("= '%s'\n", buf.data());
return;
} else if (state == State::STARTASCII) { // BLOB is string
buf.push_back('\0');
for (unsigned i = 0;i < level;++i)
putchar('\t');
printf("= '%s'\n", buf.data());
return;
}
}
// Nothing string-y, so just dump it to a file
std::string filename{"tmp/"};
if (count < 10)
filename.append("0");
filename.append(std::to_string(count) + "-");
filename.append(name, 4);
if (dump) {
FILEUPtr outFile{fopen(filename.c_str(), "wb")};
if (!outFile)
throw POSIXException{errno, "Could not open " + filename};
for (unsigned i = 0;i < level;++i)
putchar('\t');
printf("Dumping BLOB of length %ld (0x%lx) to %s\n", length, length, filename.c_str());
if (fwrite(buf.data(), length, 1, outFile.get()) != 1)
throw POSIXException{errno, "Could not write data"};
} else {
for (unsigned i = 0;i < level;++i)
putchar('\t');
printf("BLOB of length %ld (0x%lx)\n", length, length);
}
++count;
if (fwrite(obj.begin(), obj.getSize(), 1, file.get()) != 1)
throw POSIXException{errno, "Could not write"};
}
void parseChunk(FILE* iffFile, off_t start, off_t length, unsigned level = 0)
void iffDumper(IffFile::Object const& obj, bool dumpBlobs, std::string dumpPath, unsigned& blobCount, unsigned level = 0)
{
off_t pos = 0;
for (unsigned i = 0;i < level;++i)
putchar('\t');
printf("%s Length %lu (0x%.lx)", obj.getType().c_str(), obj.getSize(), obj.getSize());
while (pos < length) {
if (fseeko(iffFile, pos+start, SEEK_SET) != 0) {
throw POSIXException(errno, "Could not seek");
if (obj.isForm()) {
auto form = dynamic_cast<IffFile::Form const&>(obj);
printf(", Subtype %s\n", form.getSubtype().c_str());
for(auto it = form.childrenBegin();it != form.childrenEnd();++it)
iffDumper(*it, dumpBlobs, dumpPath, blobCount, level+1);
} else {
try {
printf(" = \"%s\"\n", static_cast<std::string>(obj).c_str());
} catch(FormatException &ex) {
if (dumpBlobs) {
std::string filename{dumpPath};
filename += obj.getType() + "-"s + std::to_string(blobCount++);
printf(" dump to %s\n", filename.c_str());
blobDump(obj, filename);
} else
printf("\n");
}
// pos < length due to loop condition, cast of difference to unsigned is OK
if (static_cast<unsigned>(length-pos) < sizeof(ChunkHeader))
return;
//throw FormatException{"Remaining size < header size"};
ChunkHeader header;
if (fread(&header, sizeof(ChunkHeader), 1, iffFile) != 1) {
if (feof(iffFile))
return;
throw POSIXException(errno, "Could not read header");
}
if (!isalnum(header.typeID[0])) {
++pos;
continue;
}
header.length = ntohl(header.length);
for (unsigned i = 0;i < level;++i)
putchar('\t');
printf("Type: %.4s, Length: %u (0x%x)", header.typeID, header.length, header.length);
if (header.length > (length-(pos+8))) {
if (header.length == (length-(pos+8))+1) {
--header.length; // Fix off-by-one errors
} else {
putchar('\n');
throw FormatException{"Length in header > remaining parent size"};
}
}
if (memcmp(header.typeID, "FORM", 4) == 0) {
char subType[4];
if (fread(&subType, 4, 1, iffFile) != 1) {
putchar('\n');
throw POSIXException(errno, "Could not read form subtype");
}
printf(", SubType: %.4s\n", subType);
try {
parseChunk(iffFile, start+pos+12, header.length-4, level+1);
} catch (FormatException &ex) {
for (unsigned i = 0;i < level;++i)
putchar('\t');
printf("Error parsing sub-chunk: %s\n", ex.toString().c_str());
}
} else {
putchar('\n');
parseBlob(iffFile, start+pos+8, header.length, header.typeID, level+1);
}
pos += header.length+8;
}
}
void usage(char *argv0) {
fprintf(stderr, "Usage: %s [-sh] [-d dest] iff-file\n", argv0);
fprintf(stderr, "\t-s\tPrint the iff-file's structure\n");
fprintf(stderr, "\t-d dest\tDump BLOBs as files to dest/\n");
fprintf(stderr, "\t-h\tPrint this help\n");
}
int main(int argc, char *argv[])
{
if (argc != 2) {
fprintf(stderr, "Usage: %s iff-file\n", argv[0]);
return 1;
}
bool printStructure = false, dumpBlobs = false;
std::string dumpPath, iffFile;
{
int opt;
while ((opt = getopt(argc, argv, "hsd:")) != -1) {
switch (opt) {
case 'h':
usage(argv[0]);
return 0;
case 's':
printStructure = true;
break;
case 'd':
dumpPath = optarg;
dumpBlobs = true;
break;
default:
usage(argv[0]);
return 1;
}
}
if (optind >= argc) {
usage(argv[0]);
return 1;
}
iffFile = argv[optind];
}
try {
FILEUPtr iffFile{fopen(argv[1], "rb")};
if (!iffFile) {
throw POSIXException{errno, "Could not open "s + argv[1]};
FILEUPtr iffFD{fopen(iffFile.c_str(), "rb")};
if (!iffFD) {
throw POSIXException{errno, "Could not open "s + iffFile};
}
struct stat statBuf;
if (fstat(fileno(iffFile.get()), &statBuf) != 0) {
if (fstat(fileno(iffFD.get()), &statBuf) != 0) {
throw POSIXException(errno, "Could not stat");
}
char *mmapBase = static_cast<char*>(mmap(nullptr, statBuf.st_size, PROT_READ, MAP_SHARED, fileno(iffFD.get()), 0));
if (!mmapBase)
throw POSIXException(errno, "mmap failed");
parseChunk(iffFile.get(), 0, statBuf.st_size);
try {
IffFile iff{mmapBase, static_cast<size_t>(statBuf.st_size)};
if (printStructure) {
unsigned blobCount = 0;
iffDumper(iff.getRoot(), dumpBlobs, dumpPath, blobCount);
}
} catch(...) {
munmap(mmapBase, statBuf.st_size);
throw;
}
if (munmap(mmapBase, statBuf.st_size) != 0)
fprintf(stderr, "Warning: munmap failed: %s\n", strerror(errno));
} catch (POSIXException &ex) {
fflush(stdout);