1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/mozglue/linker/Zip.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,359 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this file,
1.6 + * You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +
1.8 +#ifndef Zip_h
1.9 +#define Zip_h
1.10 +
1.11 +#include <cstring>
1.12 +#include <stdint.h>
1.13 +#include <vector>
1.14 +#include <zlib.h>
1.15 +#include "Utils.h"
1.16 +#include "mozilla/RefPtr.h"
1.17 +
1.18 +/**
1.19 + * Forward declaration
1.20 + */
1.21 +class ZipCollection;
1.22 +
1.23 +/**
1.24 + * Class to handle access to Zip archive streams. The Zip archive is mapped
1.25 + * in memory, and streams are direct references to that mapped memory.
1.26 + * Zip files are assumed to be correctly formed. No boundary checks are
1.27 + * performed, which means hand-crafted malicious Zip archives can make the
1.28 + * code fail in bad ways. However, since the only intended use is to load
1.29 + * libraries from Zip archives, there is no interest in making this code
1.30 + * safe, since the libraries could contain malicious code anyways.
1.31 + */
1.32 +class Zip: public mozilla::AtomicRefCounted<Zip>
1.33 +{
1.34 +public:
1.35 + MOZ_DECLARE_REFCOUNTED_TYPENAME(Zip)
1.36 + /**
1.37 + * Create a Zip instance for the given file name. Returns nullptr in case
1.38 + * of failure.
1.39 + */
1.40 + static mozilla::TemporaryRef<Zip> Create(const char *filename);
1.41 +
1.42 + /**
1.43 + * Create a Zip instance using the given buffer.
1.44 + */
1.45 + static mozilla::TemporaryRef<Zip> Create(void *buffer, size_t size) {
1.46 + return Create(nullptr, buffer, size);
1.47 + }
1.48 +
1.49 +private:
1.50 + static mozilla::TemporaryRef<Zip> Create(const char *filename,
1.51 + void *buffer, size_t size);
1.52 +
1.53 + /**
1.54 + * Private constructor
1.55 + */
1.56 + Zip(const char *filename, void *buffer, size_t size);
1.57 +
1.58 +public:
1.59 + /**
1.60 + * Destructor
1.61 + */
1.62 + ~Zip();
1.63 +
1.64 + /**
1.65 + * Class used to access Zip archive item streams
1.66 + */
1.67 + class Stream
1.68 + {
1.69 + public:
1.70 + /**
1.71 + * Stream types
1.72 + */
1.73 + enum Type {
1.74 + STORE = 0,
1.75 + DEFLATE = 8
1.76 + };
1.77 +
1.78 + /**
1.79 + * Constructor
1.80 + */
1.81 + Stream(): compressedBuf(nullptr), compressedSize(0), uncompressedSize(0)
1.82 + , type(STORE) { }
1.83 +
1.84 + /**
1.85 + * Getters
1.86 + */
1.87 + const void *GetBuffer() { return compressedBuf; }
1.88 + size_t GetSize() { return compressedSize; }
1.89 + size_t GetUncompressedSize() { return uncompressedSize; }
1.90 + Type GetType() { return type; }
1.91 +
1.92 + /**
1.93 + * Returns a z_stream for use with inflate functions using the given
1.94 + * buffer as inflate output. The caller is expected to allocate enough
1.95 + * memory for the Stream uncompressed size.
1.96 + */
1.97 + z_stream GetZStream(void *buf)
1.98 + {
1.99 + z_stream zStream;
1.100 + memset(&zStream, 0, sizeof(zStream));
1.101 + zStream.avail_in = compressedSize;
1.102 + zStream.next_in = reinterpret_cast<Bytef *>(
1.103 + const_cast<void *>(compressedBuf));
1.104 + zStream.avail_out = uncompressedSize;
1.105 + zStream.next_out = static_cast<Bytef *>(buf);
1.106 + return zStream;
1.107 + }
1.108 +
1.109 + protected:
1.110 + friend class Zip;
1.111 + const void *compressedBuf;
1.112 + size_t compressedSize;
1.113 + size_t uncompressedSize;
1.114 + Type type;
1.115 + };
1.116 +
1.117 + /**
1.118 + * Returns a stream from the Zip archive.
1.119 + */
1.120 + bool GetStream(const char *path, Stream *out) const;
1.121 +
1.122 + /**
1.123 + * Returns the file name of the archive
1.124 + */
1.125 + const char *GetName() const
1.126 + {
1.127 + return name;
1.128 + }
1.129 +
1.130 +private:
1.131 + /* File name of the archive */
1.132 + char *name;
1.133 + /* Address where the Zip archive is mapped */
1.134 + void *mapped;
1.135 + /* Size of the archive */
1.136 + size_t size;
1.137 +
1.138 + /**
1.139 + * Strings (file names, comments, etc.) in the Zip headers are NOT zero
1.140 + * terminated. This class is a helper around them.
1.141 + */
1.142 + class StringBuf
1.143 + {
1.144 + public:
1.145 + /**
1.146 + * Constructor
1.147 + */
1.148 + StringBuf(const char *buf, size_t length): buf(buf), length(length) { }
1.149 +
1.150 + /**
1.151 + * Returns whether the string has the same content as the given zero
1.152 + * terminated string.
1.153 + */
1.154 + bool Equals(const char *str) const
1.155 + {
1.156 + return strncmp(str, buf, length) == 0;
1.157 + }
1.158 +
1.159 + private:
1.160 + const char *buf;
1.161 + size_t length;
1.162 + };
1.163 +
1.164 +/* All the following types need to be packed */
1.165 +#pragma pack(1)
1.166 +public:
1.167 + /**
1.168 + * A Zip archive is an aggregate of entities which all start with a
1.169 + * signature giving their type. This template is to be used as a base
1.170 + * class for these entities.
1.171 + */
1.172 + template <typename T>
1.173 + class SignedEntity
1.174 + {
1.175 + public:
1.176 + /**
1.177 + * Equivalent to reinterpret_cast<const T *>(buf), with an additional
1.178 + * check of the signature.
1.179 + */
1.180 + static const T *validate(const void *buf)
1.181 + {
1.182 + const T *ret = static_cast<const T *>(buf);
1.183 + if (ret->signature == T::magic)
1.184 + return ret;
1.185 + return nullptr;
1.186 + }
1.187 +
1.188 + SignedEntity(uint32_t magic): signature(magic) { }
1.189 + private:
1.190 + le_uint32 signature;
1.191 + };
1.192 +
1.193 +private:
1.194 + /**
1.195 + * Header used to describe a Local File entry. The header is followed by
1.196 + * the file name and an extra field, then by the data stream.
1.197 + */
1.198 + struct LocalFile: public SignedEntity<LocalFile>
1.199 + {
1.200 + /* Signature for a Local File header */
1.201 + static const uint32_t magic = 0x04034b50;
1.202 +
1.203 + /**
1.204 + * Returns the file name
1.205 + */
1.206 + StringBuf GetName() const
1.207 + {
1.208 + return StringBuf(reinterpret_cast<const char *>(this) + sizeof(*this),
1.209 + filenameSize);
1.210 + }
1.211 +
1.212 + /**
1.213 + * Returns a pointer to the data associated with this header
1.214 + */
1.215 + const void *GetData() const
1.216 + {
1.217 + return reinterpret_cast<const char *>(this) + sizeof(*this)
1.218 + + filenameSize + extraFieldSize;
1.219 + }
1.220 +
1.221 + le_uint16 minVersion;
1.222 + le_uint16 generalFlag;
1.223 + le_uint16 compression;
1.224 + le_uint16 lastModifiedTime;
1.225 + le_uint16 lastModifiedDate;
1.226 + le_uint32 CRC32;
1.227 + le_uint32 compressedSize;
1.228 + le_uint32 uncompressedSize;
1.229 + le_uint16 filenameSize;
1.230 + le_uint16 extraFieldSize;
1.231 + };
1.232 +
1.233 + /**
1.234 + * In some cases, when a zip archive is created, compressed size and CRC
1.235 + * are not known when writing the Local File header. In these cases, the
1.236 + * 3rd bit of the general flag in the Local File header is set, and there
1.237 + * is an additional header following the compressed data.
1.238 + */
1.239 + struct DataDescriptor: public SignedEntity<DataDescriptor>
1.240 + {
1.241 + /* Signature for a Data Descriptor header */
1.242 + static const uint32_t magic = 0x08074b50;
1.243 +
1.244 + le_uint32 CRC32;
1.245 + le_uint32 compressedSize;
1.246 + le_uint32 uncompressedSize;
1.247 + };
1.248 +
1.249 + /**
1.250 + * Header used to describe a Central Directory Entry. The header is
1.251 + * followed by the file name, an extra field, and a comment.
1.252 + */
1.253 + struct DirectoryEntry: public SignedEntity<DirectoryEntry>
1.254 + {
1.255 + /* Signature for a Central Directory Entry header */
1.256 + static const uint32_t magic = 0x02014b50;
1.257 +
1.258 + /**
1.259 + * Returns the file name
1.260 + */
1.261 + StringBuf GetName() const
1.262 + {
1.263 + return StringBuf(reinterpret_cast<const char *>(this) + sizeof(*this),
1.264 + filenameSize);
1.265 + }
1.266 +
1.267 + /**
1.268 + * Returns the Central Directory Entry following this one.
1.269 + */
1.270 + const DirectoryEntry *GetNext() const
1.271 + {
1.272 + return validate(reinterpret_cast<const char *>(this) + sizeof(*this)
1.273 + + filenameSize + extraFieldSize + fileCommentSize);
1.274 + }
1.275 +
1.276 + le_uint16 creatorVersion;
1.277 + le_uint16 minVersion;
1.278 + le_uint16 generalFlag;
1.279 + le_uint16 compression;
1.280 + le_uint16 lastModifiedTime;
1.281 + le_uint16 lastModifiedDate;
1.282 + le_uint32 CRC32;
1.283 + le_uint32 compressedSize;
1.284 + le_uint32 uncompressedSize;
1.285 + le_uint16 filenameSize;
1.286 + le_uint16 extraFieldSize;
1.287 + le_uint16 fileCommentSize;
1.288 + le_uint16 diskNum;
1.289 + le_uint16 internalAttributes;
1.290 + le_uint32 externalAttributes;
1.291 + le_uint32 offset;
1.292 + };
1.293 +
1.294 + /**
1.295 + * Header used to describe the End of Central Directory Record.
1.296 + */
1.297 + struct CentralDirectoryEnd: public SignedEntity<CentralDirectoryEnd>
1.298 + {
1.299 + /* Signature for the End of Central Directory Record */
1.300 + static const uint32_t magic = 0x06054b50;
1.301 +
1.302 + le_uint16 diskNum;
1.303 + le_uint16 startDisk;
1.304 + le_uint16 recordsOnDisk;
1.305 + le_uint16 records;
1.306 + le_uint32 size;
1.307 + le_uint32 offset;
1.308 + le_uint16 commentSize;
1.309 + };
1.310 +#pragma pack()
1.311 +
1.312 + /**
1.313 + * Returns the first Directory entry
1.314 + */
1.315 + const DirectoryEntry *GetFirstEntry() const;
1.316 +
1.317 + /* Pointer to the Local File Entry following the last one GetStream() used.
1.318 + * This is used by GetStream to avoid scanning the Directory Entries when the
1.319 + * requested entry is that one. */
1.320 + mutable const LocalFile *nextFile;
1.321 +
1.322 + /* Likewise for the next Directory entry */
1.323 + mutable const DirectoryEntry *nextDir;
1.324 +
1.325 + /* Pointer to the Directory entries */
1.326 + mutable const DirectoryEntry *entries;
1.327 +};
1.328 +
1.329 +/**
1.330 + * Class for bookkeeping Zip instances
1.331 + */
1.332 +class ZipCollection
1.333 +{
1.334 +public:
1.335 + static ZipCollection Singleton;
1.336 +
1.337 + /**
1.338 + * Get a Zip instance for the given path. If there is an existing one
1.339 + * already, return that one, otherwise create a new one.
1.340 + */
1.341 + static mozilla::TemporaryRef<Zip> GetZip(const char *path);
1.342 +
1.343 +protected:
1.344 + friend class Zip;
1.345 + /**
1.346 + * Register the given Zip instance. This method is meant to be called
1.347 + * by Zip::Create.
1.348 + */
1.349 + static void Register(Zip *zip);
1.350 +
1.351 + /**
1.352 + * Forget about the given Zip instance. This method is meant to be called
1.353 + * by the Zip destructor.
1.354 + */
1.355 + static void Forget(Zip *zip);
1.356 +
1.357 +private:
1.358 + /* Zip instances bookkept in this collection */
1.359 + std::vector<Zip *> zips;
1.360 +};
1.361 +
1.362 +#endif /* Zip_h */
