Bug 683127 part 1 - Simple Zip reader for the new ELF Linker. r=tglek,r=mwu
new file mode 100644
--- /dev/null
+++ b/mozglue/linker/Logging.h
@@ -0,0 +1,22 @@
+/* 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 Logging_h
+#define Logging_h
+
+#ifdef ANDROID
+#include <android/log.h>
+#define log(...) __android_log_print(ANDROID_LOG_ERROR, "GeckoLinker", __VA_ARGS__)
+#else
+#include <cstdio>
+#define log(format, ...) fprintf(stderr, format "\n", ##__VA_ARGS__)
+#endif
+
+#ifdef MOZ_DEBUG_LINKER
+#define debug log
+#else
+#define debug(...)
+#endif
+
+#endif /* Logging_h */
new file mode 100644
--- /dev/null
+++ b/mozglue/linker/Makefile.in
@@ -0,0 +1,21 @@
+# 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/.
+
+DEPTH = ../..
+topsrcdir = @top_srcdir@
+srcdir = @srcdir@
+VPATH = @srcdir@
+
+include $(DEPTH)/config/autoconf.mk
+
+MODULE = mozglue
+LIBRARY_NAME = linker
+FORCE_STATIC_LIB= 1
+STL_FLAGS =
+
+CPPSRCS = \
+ Zip.cpp \
+ $(NULL)
+
+include $(topsrcdir)/config/rules.mk
new file mode 100644
--- /dev/null
+++ b/mozglue/linker/Utils.h
@@ -0,0 +1,93 @@
+/* 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 Utils_h
+#define Utils_h
+
+#include <stdint.h>
+
+/**
+ * On architectures that are little endian and that support unaligned reads,
+ * we can use direct type, but on others, we want to have a special class
+ * to handle conversion and alignment issues.
+ */
+#if defined(__i386__) || defined(__x86_64__)
+typedef uint16_t le_uint16;
+typedef uint32_t le_uint32;
+#else
+
+/**
+ * Template that allows to find an unsigned int type from a (computed) bit size
+ */
+template <int s> struct UInt { };
+template <> struct UInt<16> { typedef uint16_t Type; };
+template <> struct UInt<32> { typedef uint32_t Type; };
+
+/**
+ * Template to read 2 n-bit sized words as a 2*n-bit sized word, doing
+ * conversion from little endian and avoiding alignment issues.
+ */
+template <typename T>
+class le_to_cpu
+{
+public:
+ operator typename UInt<16 * sizeof(T)>::Type() const
+ {
+ return (b << (sizeof(T) * 8)) | a;
+ }
+private:
+ T a, b;
+};
+
+/**
+ * Type definitions
+ */
+typedef le_to_cpu<unsigned char> le_uint16;
+typedef le_to_cpu<le_uint16> le_uint32;
+#endif
+
+/**
+ * AutoCloseFD is a RAII wrapper for POSIX file descriptors
+ */
+class AutoCloseFD
+{
+public:
+ AutoCloseFD(): fd(-1) { }
+ AutoCloseFD(int fd): fd(fd) { }
+ ~AutoCloseFD()
+ {
+ if (fd != -1)
+ close(fd);
+ }
+
+ operator int() const
+ {
+ return fd;
+ }
+
+ int forget()
+ {
+ int _fd = fd;
+ fd = -1;
+ return _fd;
+ }
+
+ bool operator ==(int other) const
+ {
+ return fd == other;
+ }
+
+ int operator =(int other)
+ {
+ if (fd != -1)
+ close(fd);
+ fd = other;
+ return fd;
+ }
+
+private:
+ int fd;
+};
+
+#endif /* Utils_h */
new file mode 100644
--- /dev/null
+++ b/mozglue/linker/Zip.cpp
@@ -0,0 +1,180 @@
+/* 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/. */
+
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <unistd.h>
+#include <cstdlib>
+#include <algorithm>
+#include "Logging.h"
+#include "Zip.h"
+
+Zip::Zip(const char *filename, ZipCollection *collection)
+: name(strdup(filename))
+, mapped(MAP_FAILED)
+, nextDir(NULL)
+, entries(NULL)
+, parent(collection)
+{
+ /* Open and map the file in memory */
+ AutoCloseFD fd(open(name, O_RDONLY));
+ if (fd == -1) {
+ log("Error opening %s: %s", filename, strerror(errno));
+ return;
+ }
+ struct stat st;
+ if (fstat(fd, &st) == -1) {
+ log("Error stating %s: %s", filename, strerror(errno));
+ return;
+ }
+ size = st.st_size;
+ if (size <= sizeof(CentralDirectoryEnd)) {
+ log("Error reading %s: too short", filename);
+ return;
+ }
+ mapped = mmap(NULL, size, PROT_READ, MAP_SHARED, fd, 0);
+ if (mapped == MAP_FAILED) {
+ log("Error mmapping %s: %s", filename, strerror(errno));
+ return;
+ }
+ debug("Mapped %s @%p", filename, mapped);
+
+ /* Store the first Local File entry */
+ nextFile = LocalFile::validate(mapped);
+}
+
+Zip::~Zip()
+{
+ if (parent)
+ parent->Forget(this);
+ if (mapped != MAP_FAILED) {
+ munmap(mapped, size);
+ debug("Unmapped %s @%p", name, mapped);
+ }
+ free(name);
+}
+
+bool
+Zip::GetStream(const char *path, Zip::Stream *out) const
+{
+ debug("%s - GetFile %s", name, path);
+ /* Fast path: if the Local File header on store matches, we can return the
+ * corresponding stream right away.
+ * However, the Local File header may not contain enough information, in
+ * which case the 3rd bit on the generalFlag is set. Unfortunately, this
+ * bit is also set in some archives even when we do have the data (most
+ * notably the android packages as built by the Mozilla build system).
+ * So instead of testing the generalFlag bit, only use the fast path when
+ * we haven't read the central directory entries yet, and when the
+ * compressed size as defined in the header is not filled (which is a
+ * normal condition for the bit to be set). */
+ if (nextFile && nextFile->GetName().Equals(path) &&
+ !entries && (nextFile->compressedSize != 0)) {
+ debug("%s - %s was next file: fast path", name, path);
+ /* Fill Stream info from Local File header content */
+ const char *data = reinterpret_cast<const char *>(nextFile->GetData());
+ out->compressedBuf = data;
+ out->compressedSize = nextFile->compressedSize;
+ out->uncompressedSize = nextFile->uncompressedSize;
+ out->type = static_cast<Stream::Type>(uint16_t(nextFile->compression));
+
+ /* Find the next Local File header. It is usually simply following the
+ * compressed stream, but in cases where the 3rd bit of the generalFlag
+ * is set, there is a Data Descriptor header before. */
+ data += nextFile->compressedSize;
+ if ((nextFile->generalFlag & 0x8) && DataDescriptor::validate(data)) {
+ data += sizeof(DataDescriptor);
+ }
+ nextFile = LocalFile::validate(data);
+ return true;
+ }
+
+ /* If the directory entry we have in store doesn't match, scan the Central
+ * Directory for the entry corresponding to the given path */
+ if (!nextDir || !nextDir->GetName().Equals(path)) {
+ const DirectoryEntry *entry = GetFirstEntry();
+ debug("%s - Scan directory entries in search for %s", name, path);
+ while (entry && !entry->GetName().Equals(path)) {
+ entry = entry->GetNext();
+ }
+ nextDir = entry;
+ }
+ if (!nextDir) {
+ debug("%s - Couldn't find %s", name, path);
+ return false;
+ }
+
+ /* Find the Local File header corresponding to the Directory entry that
+ * was found. */
+ nextFile = LocalFile::validate(static_cast<const char *>(mapped)
+ + nextDir->offset);
+ if (!nextFile) {
+ log("%s - Couldn't find the Local File header for %s", name, path);
+ return false;
+ }
+
+ /* Fill Stream info from Directory entry content */
+ const char *data = reinterpret_cast<const char *>(nextFile->GetData());
+ out->compressedBuf = data;
+ out->compressedSize = nextDir->compressedSize;
+ out->uncompressedSize = nextDir->uncompressedSize;
+ out->type = static_cast<Stream::Type>(uint16_t(nextDir->compression));
+
+ /* Store the next directory entry */
+ nextDir = nextDir->GetNext();
+ nextFile = NULL;
+ return true;
+}
+
+const Zip::DirectoryEntry *
+Zip::GetFirstEntry() const
+{
+ if (entries || mapped == MAP_FAILED)
+ return entries; // entries is NULL in the second case above
+
+ const CentralDirectoryEnd *end = NULL;
+ const char *_end = static_cast<const char *>(mapped) + size
+ - sizeof(CentralDirectoryEnd);
+
+ /* Scan for the Central Directory End */
+ for (; _end > mapped && !end; _end--)
+ end = CentralDirectoryEnd::validate(_end);
+ if (!end) {
+ log("%s - Couldn't find end of central directory record", name);
+ return NULL;
+ }
+
+ entries = DirectoryEntry::validate(static_cast<const char *>(mapped)
+ + end->offset);
+ if (!entries) {
+ log("%s - Couldn't find central directory record", name);
+ }
+ return entries;
+}
+
+mozilla::TemporaryRef<Zip>
+ZipCollection::GetZip(const char *path)
+{
+ /* Search the list of Zips we already have for a match */
+ for (std::vector<Zip *>::iterator it = zips.begin(); it < zips.end(); ++it) {
+ if (strcmp((*it)->GetName(), path) == 0)
+ return *it;
+ }
+ Zip *zip = new Zip(path, this);
+ zips.push_back(zip);
+ return zip;
+}
+
+void
+ZipCollection::Forget(Zip *zip)
+{
+ debug("ZipCollection::Forget(\"%s\")", zip->GetName());
+ std::vector<Zip *>::iterator it = std::find(zips.begin(), zips.end(), zip);
+ if (*it == zip)
+ zips.erase(it);
+ else
+ debug("ZipCollection::Forget: didn't find \"%s\" in bookkeeping", zip->GetName());
+}
new file mode 100644
--- /dev/null
+++ b/mozglue/linker/Zip.h
@@ -0,0 +1,311 @@
+/* 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 "Utils.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::RefCounted<Zip>
+{
+public:
+ /**
+ * Create a Zip instance for the given file name. In case of error, the
+ * Zip instance is still created but methods will error out.
+ */
+ Zip(const char *filename, ZipCollection *collection = NULL);
+
+ /**
+ * Destructor
+ */
+ ~Zip();
+
+ /**
+ * Class used to access Zip archive item streams
+ */
+ class Stream
+ {
+ public:
+ /**
+ * Stream types
+ */
+ enum Type {
+ STORE = 0,
+ DEFLATE = 8
+ };
+
+ /**
+ * Constructor
+ */
+ Stream(): compressedBuf(NULL), compressedSize(0), uncompressedSize(0)
+ , type(STORE) { }
+
+ const void *GetBuffer() { return compressedBuf; }
+ size_t GetSize() { return compressedSize; }
+ size_t GetUncompressedSize() { return uncompressedSize; }
+ Type GetType() { return type; }
+
+ protected:
+ friend class Zip;
+ const void *compressedBuf;
+ size_t compressedSize;
+ size_t uncompressedSize;
+ 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;
+ }
+
+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;
+ }
+
+ private:
+ const char *buf;
+ size_t length;
+ };
+
+/* All the following types need to be packed */
+#pragma pack(1)
+ /**
+ * 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 NULL;
+ }
+ private:
+ le_uint32 signature;
+ };
+
+ /**
+ * 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;
+
+ /* ZipCollection containing this Zip */
+ mutable ZipCollection *parent;
+};
+
+/**
+ * Class for bookkeeping Zip instances
+ */
+class ZipCollection
+{
+public:
+ /**
+ * Get a Zip instance for the given path. If there is an existing one
+ * already, return that one, otherwise create a new one.
+ */
+ mozilla::TemporaryRef<Zip> GetZip(const char *path);
+
+protected:
+ /**
+ * Forget about the given Zip instance. This method is meant to be called
+ * by the Zip destructor.
+ */
+ friend Zip::~Zip();
+ void Forget(Zip *zip);
+
+private:
+ /* Zip instances bookkept in this collection */
+ std::vector<Zip *> zips;
+};
+
+#endif /* Zip_h */