michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
michael@0:  * You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef Zip_h
michael@0: #define Zip_h
michael@0: 
michael@0: #include <cstring>
michael@0: #include <stdint.h>
michael@0: #include <vector>
michael@0: #include <zlib.h>
michael@0: #include "Utils.h"
michael@0: #include "mozilla/RefPtr.h"
michael@0: 
michael@0: /**
michael@0:  * Forward declaration
michael@0:  */
michael@0: class ZipCollection;
michael@0: 
michael@0: /**
michael@0:  * Class to handle access to Zip archive streams. The Zip archive is mapped
michael@0:  * in memory, and streams are direct references to that mapped memory.
michael@0:  * Zip files are assumed to be correctly formed. No boundary checks are
michael@0:  * performed, which means hand-crafted malicious Zip archives can make the
michael@0:  * code fail in bad ways. However, since the only intended use is to load
michael@0:  * libraries from Zip archives, there is no interest in making this code
michael@0:  * safe, since the libraries could contain malicious code anyways.
michael@0:  */
michael@0: class Zip: public mozilla::AtomicRefCounted<Zip>
michael@0: {
michael@0: public:
michael@0:   MOZ_DECLARE_REFCOUNTED_TYPENAME(Zip)
michael@0:   /**
michael@0:    * Create a Zip instance for the given file name. Returns nullptr in case
michael@0:    * of failure.
michael@0:    */
michael@0:   static mozilla::TemporaryRef<Zip> Create(const char *filename);
michael@0: 
michael@0:   /**
michael@0:    * Create a Zip instance using the given buffer.
michael@0:    */
michael@0:   static mozilla::TemporaryRef<Zip> Create(void *buffer, size_t size) {
michael@0:     return Create(nullptr, buffer, size);
michael@0:   }
michael@0: 
michael@0: private:
michael@0:   static mozilla::TemporaryRef<Zip> Create(const char *filename,
michael@0:                                            void *buffer, size_t size);
michael@0: 
michael@0:   /**
michael@0:    * Private constructor
michael@0:    */
michael@0:   Zip(const char *filename, void *buffer, size_t size);
michael@0: 
michael@0: public:
michael@0:   /**
michael@0:    * Destructor
michael@0:    */
michael@0:   ~Zip();
michael@0: 
michael@0:   /**
michael@0:    * Class used to access Zip archive item streams
michael@0:    */
michael@0:   class Stream
michael@0:   {
michael@0:   public:
michael@0:     /**
michael@0:      * Stream types
michael@0:      */
michael@0:     enum Type {
michael@0:       STORE = 0,
michael@0:       DEFLATE = 8
michael@0:     };
michael@0: 
michael@0:     /**
michael@0:      * Constructor
michael@0:      */
michael@0:     Stream(): compressedBuf(nullptr), compressedSize(0), uncompressedSize(0)
michael@0:             , type(STORE) { }
michael@0: 
michael@0:     /**
michael@0:      * Getters
michael@0:      */
michael@0:     const void *GetBuffer() { return compressedBuf; }
michael@0:     size_t GetSize() { return compressedSize; }
michael@0:     size_t GetUncompressedSize() { return uncompressedSize; }
michael@0:     Type GetType() { return type; }
michael@0: 
michael@0:     /**
michael@0:      * Returns a z_stream for use with inflate functions using the given
michael@0:      * buffer as inflate output. The caller is expected to allocate enough
michael@0:      * memory for the Stream uncompressed size.
michael@0:      */
michael@0:     z_stream GetZStream(void *buf)
michael@0:     {
michael@0:       z_stream zStream;
michael@0:       memset(&zStream, 0, sizeof(zStream));
michael@0:       zStream.avail_in = compressedSize;
michael@0:       zStream.next_in = reinterpret_cast<Bytef *>(
michael@0:                         const_cast<void *>(compressedBuf));
michael@0:       zStream.avail_out = uncompressedSize;
michael@0:       zStream.next_out = static_cast<Bytef *>(buf);
michael@0:       return zStream;
michael@0:     }
michael@0: 
michael@0:   protected:
michael@0:     friend class Zip;
michael@0:     const void *compressedBuf;
michael@0:     size_t compressedSize;
michael@0:     size_t uncompressedSize;
michael@0:     Type type;
michael@0:   };
michael@0: 
michael@0:   /**
michael@0:    * Returns a stream from the Zip archive.
michael@0:    */
michael@0:   bool GetStream(const char *path, Stream *out) const;
michael@0: 
michael@0:   /**
michael@0:    * Returns the file name of the archive
michael@0:    */
michael@0:   const char *GetName() const
michael@0:   {
michael@0:     return name;
michael@0:   }
michael@0: 
michael@0: private:
michael@0:   /* File name of the archive */
michael@0:   char *name;
michael@0:   /* Address where the Zip archive is mapped */
michael@0:   void *mapped;
michael@0:   /* Size of the archive */
michael@0:   size_t size;
michael@0: 
michael@0:   /**
michael@0:    * Strings (file names, comments, etc.) in the Zip headers are NOT zero
michael@0:    * terminated. This class is a helper around them.
michael@0:    */
michael@0:   class StringBuf
michael@0:   {
michael@0:   public:
michael@0:     /**
michael@0:      * Constructor
michael@0:      */
michael@0:     StringBuf(const char *buf, size_t length): buf(buf), length(length) { }
michael@0: 
michael@0:     /**
michael@0:      * Returns whether the string has the same content as the given zero
michael@0:      * terminated string.
michael@0:      */
michael@0:     bool Equals(const char *str) const
michael@0:     {
michael@0:       return strncmp(str, buf, length) == 0;
michael@0:     }
michael@0: 
michael@0:   private:
michael@0:     const char *buf;
michael@0:     size_t length;
michael@0:   };
michael@0: 
michael@0: /* All the following types need to be packed */
michael@0: #pragma pack(1)
michael@0: public:
michael@0:   /**
michael@0:    * A Zip archive is an aggregate of entities which all start with a
michael@0:    * signature giving their type. This template is to be used as a base
michael@0:    * class for these entities.
michael@0:    */
michael@0:   template <typename T>
michael@0:   class SignedEntity
michael@0:   {
michael@0:   public:
michael@0:     /**
michael@0:      * Equivalent to reinterpret_cast<const T *>(buf), with an additional
michael@0:      * check of the signature.
michael@0:      */
michael@0:     static const T *validate(const void *buf)
michael@0:     {
michael@0:       const T *ret = static_cast<const T *>(buf);
michael@0:       if (ret->signature == T::magic)
michael@0:         return ret;
michael@0:       return nullptr;
michael@0:     }
michael@0: 
michael@0:     SignedEntity(uint32_t magic): signature(magic) { }
michael@0:   private:
michael@0:     le_uint32 signature;
michael@0:   };
michael@0: 
michael@0: private:
michael@0:   /**
michael@0:    * Header used to describe a Local File entry. The header is followed by
michael@0:    * the file name and an extra field, then by the data stream.
michael@0:    */
michael@0:   struct LocalFile: public SignedEntity<LocalFile>
michael@0:   {
michael@0:     /* Signature for a Local File header */
michael@0:     static const uint32_t magic = 0x04034b50;
michael@0: 
michael@0:     /**
michael@0:      * Returns the file name
michael@0:      */
michael@0:     StringBuf GetName() const
michael@0:     {
michael@0:       return StringBuf(reinterpret_cast<const char *>(this) + sizeof(*this),
michael@0:                        filenameSize);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Returns a pointer to the data associated with this header
michael@0:      */
michael@0:     const void *GetData() const
michael@0:     {
michael@0:       return reinterpret_cast<const char *>(this) + sizeof(*this)
michael@0:              + filenameSize + extraFieldSize;
michael@0:     }
michael@0:     
michael@0:     le_uint16 minVersion;
michael@0:     le_uint16 generalFlag;
michael@0:     le_uint16 compression;
michael@0:     le_uint16 lastModifiedTime;
michael@0:     le_uint16 lastModifiedDate;
michael@0:     le_uint32 CRC32;
michael@0:     le_uint32 compressedSize;
michael@0:     le_uint32 uncompressedSize;
michael@0:     le_uint16 filenameSize;
michael@0:     le_uint16 extraFieldSize;
michael@0:   };
michael@0: 
michael@0:   /**
michael@0:    * In some cases, when a zip archive is created, compressed size and CRC
michael@0:    * are not known when writing the Local File header. In these cases, the
michael@0:    * 3rd bit of the general flag in the Local File header is set, and there
michael@0:    * is an additional header following the compressed data.
michael@0:    */
michael@0:   struct DataDescriptor: public SignedEntity<DataDescriptor>
michael@0:   {
michael@0:     /* Signature for a Data Descriptor header */
michael@0:     static const uint32_t magic = 0x08074b50;
michael@0: 
michael@0:     le_uint32 CRC32;
michael@0:     le_uint32 compressedSize;
michael@0:     le_uint32 uncompressedSize;
michael@0:   };
michael@0: 
michael@0:   /**
michael@0:    * Header used to describe a Central Directory Entry. The header is
michael@0:    * followed by the file name, an extra field, and a comment.
michael@0:    */
michael@0:   struct DirectoryEntry: public SignedEntity<DirectoryEntry>
michael@0:   {
michael@0:     /* Signature for a Central Directory Entry header */
michael@0:     static const uint32_t magic = 0x02014b50;
michael@0: 
michael@0:     /**
michael@0:      * Returns the file name
michael@0:      */
michael@0:     StringBuf GetName() const
michael@0:     {
michael@0:       return StringBuf(reinterpret_cast<const char *>(this) + sizeof(*this),
michael@0:                        filenameSize);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Returns  the Central Directory Entry following this one.
michael@0:      */
michael@0:     const DirectoryEntry *GetNext() const
michael@0:     {
michael@0:       return validate(reinterpret_cast<const char *>(this) + sizeof(*this)
michael@0:                       + filenameSize + extraFieldSize + fileCommentSize);
michael@0:     }
michael@0: 
michael@0:     le_uint16 creatorVersion;
michael@0:     le_uint16 minVersion;
michael@0:     le_uint16 generalFlag;
michael@0:     le_uint16 compression;
michael@0:     le_uint16 lastModifiedTime;
michael@0:     le_uint16 lastModifiedDate;
michael@0:     le_uint32 CRC32;
michael@0:     le_uint32 compressedSize;
michael@0:     le_uint32 uncompressedSize;
michael@0:     le_uint16 filenameSize;
michael@0:     le_uint16 extraFieldSize;
michael@0:     le_uint16 fileCommentSize;
michael@0:     le_uint16 diskNum;
michael@0:     le_uint16 internalAttributes;
michael@0:     le_uint32 externalAttributes;
michael@0:     le_uint32 offset;
michael@0:   };
michael@0: 
michael@0:   /**
michael@0:    * Header used to describe the End of Central Directory Record.
michael@0:    */
michael@0:   struct CentralDirectoryEnd: public SignedEntity<CentralDirectoryEnd>
michael@0:   {
michael@0:     /* Signature for the End of Central Directory Record */
michael@0:     static const uint32_t magic = 0x06054b50;
michael@0: 
michael@0:     le_uint16 diskNum;
michael@0:     le_uint16 startDisk;
michael@0:     le_uint16 recordsOnDisk;
michael@0:     le_uint16 records;
michael@0:     le_uint32 size;
michael@0:     le_uint32 offset;
michael@0:     le_uint16 commentSize;
michael@0:   };
michael@0: #pragma pack()
michael@0: 
michael@0:   /**
michael@0:    * Returns the first Directory entry
michael@0:    */
michael@0:   const DirectoryEntry *GetFirstEntry() const;
michael@0: 
michael@0:   /* Pointer to the Local File Entry following the last one GetStream() used.
michael@0:    * This is used by GetStream to avoid scanning the Directory Entries when the
michael@0:    * requested entry is that one. */
michael@0:   mutable const LocalFile *nextFile;
michael@0: 
michael@0:   /* Likewise for the next Directory entry */
michael@0:   mutable const DirectoryEntry *nextDir;
michael@0: 
michael@0:   /* Pointer to the Directory entries */
michael@0:   mutable const DirectoryEntry *entries;
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * Class for bookkeeping Zip instances
michael@0:  */
michael@0: class ZipCollection
michael@0: {
michael@0: public:
michael@0:   static ZipCollection Singleton;
michael@0: 
michael@0:   /**
michael@0:    * Get a Zip instance for the given path. If there is an existing one
michael@0:    * already, return that one, otherwise create a new one.
michael@0:    */
michael@0:   static mozilla::TemporaryRef<Zip> GetZip(const char *path);
michael@0: 
michael@0: protected:
michael@0:   friend class Zip;
michael@0:   /**
michael@0:    * Register the given Zip instance. This method is meant to be called
michael@0:    * by Zip::Create.
michael@0:    */
michael@0:   static void Register(Zip *zip);
michael@0: 
michael@0:   /**
michael@0:    * Forget about the given Zip instance. This method is meant to be called
michael@0:    * by the Zip destructor.
michael@0:    */
michael@0:   static void Forget(Zip *zip);
michael@0: 
michael@0: private:
michael@0:   /* Zip instances bookkept in this collection */
michael@0:   std::vector<Zip *> zips;
michael@0: };
michael@0: 
michael@0: #endif /* Zip_h */