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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:22:09 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:22:09 +0000
commit43a97878ce14b72f0981164f87f2e35e14151312 (patch)
tree620249daf56c0258faa40cbdcf9cfba06de2a846 /mozglue/linker/Zip.h
parentInitial commit. (diff)
downloadfirefox-upstream.tar.xz
firefox-upstream.zip
Adding upstream version 110.0.1.upstream/110.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'mozglue/linker/Zip.h')
-rw-r--r--mozglue/linker/Zip.h388
1 files changed, 388 insertions, 0 deletions
diff --git a/mozglue/linker/Zip.h b/mozglue/linker/Zip.h
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+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef Zip_h
+#define Zip_h
+
+#include <cstring>
+#include <stdint.h>
+#include <vector>
+#include <zlib.h>
+#include <pthread.h>
+#include "Utils.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/RefCounted.h"
+#include "mozilla/RefPtr.h"
+
+/**
+ * Forward declaration
+ */
+class ZipCollection;
+
+/**
+ * Class to handle access to Zip archive streams. The Zip archive is mapped
+ * in memory, and streams are direct references to that mapped memory.
+ * Zip files are assumed to be correctly formed. No boundary checks are
+ * performed, which means hand-crafted malicious Zip archives can make the
+ * code fail in bad ways. However, since the only intended use is to load
+ * libraries from Zip archives, there is no interest in making this code
+ * safe, since the libraries could contain malicious code anyways.
+ */
+class Zip : public mozilla::external::AtomicRefCounted<Zip> {
+ public:
+ MOZ_DECLARE_REFCOUNTED_TYPENAME(Zip)
+ /**
+ * Create a Zip instance for the given file name. Returns nullptr in case
+ * of failure.
+ */
+ static already_AddRefed<Zip> Create(const char* filename);
+
+ /**
+ * Create a Zip instance using the given buffer.
+ */
+ static already_AddRefed<Zip> Create(void* buffer, size_t size) {
+ return Create(nullptr, buffer, size);
+ }
+
+ private:
+ static already_AddRefed<Zip> Create(const char* filename, void* buffer,
+ size_t size);
+
+ /**
+ * Private constructor
+ */
+ Zip(const char* filename, void* buffer, size_t size);
+
+ public:
+ /**
+ * Destructor
+ */
+ ~Zip();
+
+ /**
+ * Class used to access Zip archive item streams
+ */
+ class Stream {
+ public:
+ /**
+ * Stream types
+ */
+ enum Type { STORE = 0, DEFLATE = 8 };
+
+ /**
+ * Constructor
+ */
+ Stream()
+ : compressedBuf(nullptr),
+ compressedSize(0),
+ uncompressedSize(0),
+ CRC32(0),
+ type(STORE) {}
+
+ /**
+ * Getters
+ */
+ const void* GetBuffer() { return compressedBuf; }
+ size_t GetSize() { return compressedSize; }
+ size_t GetUncompressedSize() { return uncompressedSize; }
+ size_t GetCRC32() { return CRC32; }
+ Type GetType() { return type; }
+
+ /**
+ * Returns a z_stream for use with inflate functions using the given
+ * buffer as inflate output. The caller is expected to allocate enough
+ * memory for the Stream uncompressed size.
+ */
+ z_stream GetZStream(void* buf) {
+ z_stream zStream;
+ zStream.avail_in = compressedSize;
+ zStream.next_in =
+ reinterpret_cast<Bytef*>(const_cast<void*>(compressedBuf));
+ zStream.avail_out = uncompressedSize;
+ zStream.next_out = static_cast<Bytef*>(buf);
+ zStream.zalloc = nullptr;
+ zStream.zfree = nullptr;
+ zStream.opaque = nullptr;
+ return zStream;
+ }
+
+ protected:
+ friend class Zip;
+ const void* compressedBuf;
+ size_t compressedSize;
+ size_t uncompressedSize;
+ size_t CRC32;
+ Type type;
+ };
+
+ /**
+ * Returns a stream from the Zip archive.
+ */
+ bool GetStream(const char* path, Stream* out) const;
+
+ /**
+ * Returns the file name of the archive
+ */
+ const char* GetName() const { return name; }
+
+ /**
+ * Returns whether all files have correct CRC checksum.
+ */
+ bool VerifyCRCs() const;
+
+ private:
+ /* File name of the archive */
+ char* name;
+ /* Address where the Zip archive is mapped */
+ void* mapped;
+ /* Size of the archive */
+ size_t size;
+
+ /**
+ * Strings (file names, comments, etc.) in the Zip headers are NOT zero
+ * terminated. This class is a helper around them.
+ */
+ class StringBuf {
+ public:
+ /**
+ * Constructor
+ */
+ StringBuf(const char* buf, size_t length) : buf(buf), length(length) {}
+
+ /**
+ * Returns whether the string has the same content as the given zero
+ * terminated string.
+ */
+ bool Equals(const char* str) const {
+ return (strncmp(str, buf, length) == 0 && str[length] == '\0');
+ }
+
+ private:
+ const char* buf;
+ size_t length;
+ };
+
+/* All the following types need to be packed */
+#pragma pack(1)
+ public:
+ /**
+ * A Zip archive is an aggregate of entities which all start with a
+ * signature giving their type. This template is to be used as a base
+ * class for these entities.
+ */
+ template <typename T>
+ class SignedEntity {
+ public:
+ /**
+ * Equivalent to reinterpret_cast<const T *>(buf), with an additional
+ * check of the signature.
+ */
+ static const T* validate(const void* buf) {
+ const T* ret = static_cast<const T*>(buf);
+ if (ret->signature == T::magic) return ret;
+ return nullptr;
+ }
+
+ explicit SignedEntity(uint32_t magic) : signature(magic) {}
+
+ private:
+ le_uint32 signature;
+ };
+
+ private:
+ /**
+ * Header used to describe a Local File entry. The header is followed by
+ * the file name and an extra field, then by the data stream.
+ */
+ struct LocalFile : public SignedEntity<LocalFile> {
+ /* Signature for a Local File header */
+ static const uint32_t magic = 0x04034b50;
+
+ /**
+ * Returns the file name
+ */
+ StringBuf GetName() const {
+ return StringBuf(reinterpret_cast<const char*>(this) + sizeof(*this),
+ filenameSize);
+ }
+
+ /**
+ * Returns a pointer to the data associated with this header
+ */
+ const void* GetData() const {
+ return reinterpret_cast<const char*>(this) + sizeof(*this) +
+ filenameSize + extraFieldSize;
+ }
+
+ le_uint16 minVersion;
+ le_uint16 generalFlag;
+ le_uint16 compression;
+ le_uint16 lastModifiedTime;
+ le_uint16 lastModifiedDate;
+ le_uint32 CRC32;
+ le_uint32 compressedSize;
+ le_uint32 uncompressedSize;
+ le_uint16 filenameSize;
+ le_uint16 extraFieldSize;
+ };
+
+ /**
+ * In some cases, when a zip archive is created, compressed size and CRC
+ * are not known when writing the Local File header. In these cases, the
+ * 3rd bit of the general flag in the Local File header is set, and there
+ * is an additional header following the compressed data.
+ */
+ struct DataDescriptor : public SignedEntity<DataDescriptor> {
+ /* Signature for a Data Descriptor header */
+ static const uint32_t magic = 0x08074b50;
+
+ le_uint32 CRC32;
+ le_uint32 compressedSize;
+ le_uint32 uncompressedSize;
+ };
+
+ /**
+ * Header used to describe a Central Directory Entry. The header is
+ * followed by the file name, an extra field, and a comment.
+ */
+ struct DirectoryEntry : public SignedEntity<DirectoryEntry> {
+ /* Signature for a Central Directory Entry header */
+ static const uint32_t magic = 0x02014b50;
+
+ /**
+ * Returns the file name
+ */
+ StringBuf GetName() const {
+ return StringBuf(reinterpret_cast<const char*>(this) + sizeof(*this),
+ filenameSize);
+ }
+
+ /**
+ * Returns the Central Directory Entry following this one.
+ */
+ const DirectoryEntry* GetNext() const {
+ return validate(reinterpret_cast<const char*>(this) + sizeof(*this) +
+ filenameSize + extraFieldSize + fileCommentSize);
+ }
+
+ le_uint16 creatorVersion;
+ le_uint16 minVersion;
+ le_uint16 generalFlag;
+ le_uint16 compression;
+ le_uint16 lastModifiedTime;
+ le_uint16 lastModifiedDate;
+ le_uint32 CRC32;
+ le_uint32 compressedSize;
+ le_uint32 uncompressedSize;
+ le_uint16 filenameSize;
+ le_uint16 extraFieldSize;
+ le_uint16 fileCommentSize;
+ le_uint16 diskNum;
+ le_uint16 internalAttributes;
+ le_uint32 externalAttributes;
+ le_uint32 offset;
+ };
+
+ /**
+ * Header used to describe the End of Central Directory Record.
+ */
+ struct CentralDirectoryEnd : public SignedEntity<CentralDirectoryEnd> {
+ /* Signature for the End of Central Directory Record */
+ static const uint32_t magic = 0x06054b50;
+
+ le_uint16 diskNum;
+ le_uint16 startDisk;
+ le_uint16 recordsOnDisk;
+ le_uint16 records;
+ le_uint32 size;
+ le_uint32 offset;
+ le_uint16 commentSize;
+ };
+#pragma pack()
+
+ /**
+ * Returns the first Directory entry
+ */
+ const DirectoryEntry* GetFirstEntry() const;
+
+ /* Pointer to the Local File Entry following the last one GetStream() used.
+ * This is used by GetStream to avoid scanning the Directory Entries when the
+ * requested entry is that one. */
+ mutable const LocalFile* nextFile;
+
+ /* Likewise for the next Directory entry */
+ mutable const DirectoryEntry* nextDir;
+
+ /* Pointer to the Directory entries */
+ mutable const DirectoryEntry* entries;
+
+ mutable pthread_mutex_t mutex;
+};
+
+/**
+ * Class for bookkeeping Zip instances
+ */
+class ZipCollection {
+ public:
+ static ZipCollection Singleton;
+
+ /**
+ * Get a Zip instance for the given path. If there is an existing one
+ * already, return that one, otherwise create a new one.
+ */
+ static already_AddRefed<Zip> GetZip(const char* path);
+
+ protected:
+ friend class Zip;
+ friend class mozilla::detail::RefCounted<Zip,
+ mozilla::detail::AtomicRefCount>;
+
+ /**
+ * Register the given Zip instance. This method is meant to be called
+ * by Zip::Create.
+ */
+ static void Register(Zip* zip);
+
+ /**
+ * Forget about the given Zip instance. This method is meant to be called
+ * by the Zip destructor.
+ */
+ static void Forget(const Zip* zip);
+
+ private:
+ /* Zip instances bookkept in this collection */
+ std::vector<RefPtr<Zip>> zips;
+};
+
+namespace mozilla {
+namespace detail {
+
+template <>
+inline void RefCounted<Zip, AtomicRefCount>::Release() const {
+ MOZ_ASSERT(static_cast<int32_t>(mRefCnt) > 0);
+ const auto count = --mRefCnt;
+ if (count == 1) {
+ // No external references are left, attempt to remove it from the
+ // collection. If it's successfully removed from the collection, Release()
+ // will be called with mRefCnt = 1, which will finally delete this zip.
+ ZipCollection::Forget(static_cast<const Zip*>(this));
+ } else if (count == 0) {
+#ifdef DEBUG
+ mRefCnt = detail::DEAD;
+#endif
+ delete static_cast<const Zip*>(this);
+ }
+}
+
+#ifdef DEBUG
+template <>
+inline RefCounted<Zip, AtomicRefCount>::~RefCounted() {
+ MOZ_ASSERT(mRefCnt == detail::DEAD);
+}
+#endif
+
+} // namespace detail
+} // namespace mozilla
+
+#endif /* Zip_h */