/*
* Create and initialize a hash table.
*/
HashTable* dvmHashTableCreate(size_t initialSize, HashFreeFunc freeFunc)
{
HashTable* pHashTable;
assert(initialSize > 0);
pHashTable = (HashTable*) malloc(sizeof(*pHashTable));
if (pHashTable == NULL)
return NULL;
dvmInitMutex(&pHashTable->lock);
pHashTable->tableSize = dexRoundUpPower2(initialSize);
pHashTable->numEntries = pHashTable->numDeadEntries = 0;
pHashTable->freeFunc = freeFunc;
pHashTable->pEntries =
(HashEntry*) malloc(pHashTable->tableSize * sizeof(HashEntry));
if (pHashTable->pEntries == NULL) {
free(pHashTable);
return NULL;
}
memset(pHashTable->pEntries, 0, pHashTable->tableSize * sizeof(HashEntry));
return pHashTable;
}
/*
* Create the class lookup hash table.
*
* Returns newly-allocated storage.
*/
DexClassLookup* dexCreateClassLookup(DexFile* pDexFile)
{
DexClassLookup* pLookup;
int allocSize;
int i, numEntries;
int numProbes, totalProbes, maxProbes;
numProbes = totalProbes = maxProbes = 0;
assert(pDexFile != NULL);
/*
* Using a factor of 3 results in far less probing than a factor of 2,
* but almost doubles the flash storage requirements for the bootstrap
* DEX files. The overall impact on class loading performance seems
* to be minor. We could probably get some performance improvement by
* using a secondary hash.
*/
numEntries = dexRoundUpPower2(pDexFile->pHeader->classDefsSize * 2);
allocSize = offsetof(DexClassLookup, table)
+ numEntries * sizeof(pLookup->table[0]);
pLookup = (DexClassLookup*) calloc(1, allocSize);
if (pLookup == NULL)
return NULL;
pLookup->size = allocSize;
pLookup->numEntries = numEntries;
for (i = 0; i < (int)pDexFile->pHeader->classDefsSize; i++) {
const DexClassDef* pClassDef;
const char* pString;
pClassDef = dexGetClassDef(pDexFile, i);
pString = dexStringByTypeIdx(pDexFile, pClassDef->classIdx);
classLookupAdd(pDexFile, pLookup,
(u1*)pString - pDexFile->baseAddr,
(u1*)pClassDef - pDexFile->baseAddr, &numProbes);
if (numProbes > maxProbes)
maxProbes = numProbes;
totalProbes += numProbes;
}
LOGV("Class lookup: classes=%d slots=%d (%d%% occ) alloc=%d"
" total=%d max=%d\n",
pDexFile->pHeader->classDefsSize, numEntries,
(100 * pDexFile->pHeader->classDefsSize) / numEntries,
allocSize, totalProbes, maxProbes);
return pLookup;
}
/*
* Parse the Zip archive, verifying its contents and initializing internal
* data structures.
*/
static bool parseZipArchive(ZipArchive* pArchive, const MemMapping* pMap)
{
#define CHECK_OFFSET(_off) { \
if ((unsigned int) (_off) >= maxOffset) { \
LOGE("ERROR: bad offset %u (max %d): %s\n", \
(unsigned int) (_off), maxOffset, #_off); \
goto bail; \
} \
}
bool result = false;
const unsigned char* basePtr = (const unsigned char*)pMap->addr;
const unsigned char* ptr;
size_t length = pMap->length;
unsigned int i, numEntries, cdOffset;
unsigned int val;
/*
* The first 4 bytes of the file will either be the local header
* signature for the first file (kLFHSignature) or, if the archive doesn't
* have any files in it, the end-of-central-directory signature
* (kEOCDSignature).
*/
val = get4LE(basePtr);
if (val == kEOCDSignature) {
LOGI("Found Zip archive, but it looks empty\n");
goto bail;
} else if (val != kLFHSignature) {
LOGV("Not a Zip archive (found 0x%08x)\n", val);
goto bail;
}
/*
* Find the EOCD. We'll find it immediately unless they have a file
* comment.
*/
ptr = basePtr + length - kEOCDLen;
while (ptr >= basePtr) {
if (*ptr == (kEOCDSignature & 0xff) && get4LE(ptr) == kEOCDSignature)
break;
ptr--;
}
if (ptr < basePtr) {
LOGI("Could not find end-of-central-directory in Zip\n");
goto bail;
}
/*
* There are two interesting items in the EOCD block: the number of
* entries in the file, and the file offset of the start of the
* central directory.
*
* (There's actually a count of the #of entries in this file, and for
* all files which comprise a spanned archive, but for our purposes
* we're only interested in the current file. Besides, we expect the
* two to be equivalent for our stuff.)
*/
numEntries = get2LE(ptr + kEOCDNumEntries);
cdOffset = get4LE(ptr + kEOCDFileOffset);
/* valid offsets are [0,EOCD] */
unsigned int maxOffset;
maxOffset = (ptr - basePtr) +1;
LOGV("+++ numEntries=%d cdOffset=%d\n", numEntries, cdOffset);
if (numEntries == 0 || cdOffset >= length) {
LOGW("Invalid entries=%d offset=%d (len=%zd)\n",
numEntries, cdOffset, length);
goto bail;
}
/*
* Create hash table. We have a minimum 75% load factor, possibly as
* low as 50% after we round off to a power of 2. There must be at
* least one unused entry to avoid an infinite loop during creation.
*/
pArchive->mNumEntries = numEntries;
pArchive->mHashTableSize = dexRoundUpPower2(1 + (numEntries * 4) / 3);
pArchive->mHashTable = (ZipHashEntry*)
calloc(pArchive->mHashTableSize, sizeof(ZipHashEntry));
/*
* Walk through the central directory, adding entries to the hash
* table.
*/
ptr = basePtr + cdOffset;
for (i = 0; i < numEntries; i++) {
unsigned int fileNameLen, extraLen, commentLen, localHdrOffset;
const unsigned char* localHdr;
unsigned int hash;
if (get4LE(ptr) != kCDESignature) {
LOGW("Missed a central dir sig (at %d)\n", i);
goto bail;
}
if (ptr + kCDELen > basePtr + length) {
LOGW("Ran off the end (at %d)\n", i);
goto bail;
}
localHdrOffset = get4LE(ptr + kCDELocalOffset);
CHECK_OFFSET(localHdrOffset);
fileNameLen = get2LE(ptr + kCDENameLen);
extraLen = get2LE(ptr + kCDEExtraLen);
commentLen = get2LE(ptr + kCDECommentLen);
//LOGV("+++ %d: localHdr=%d fnl=%d el=%d cl=%d\n",
// i, localHdrOffset, fileNameLen, extraLen, commentLen);
//LOGV(" '%.*s'\n", fileNameLen, ptr + kCDELen);
/* add the CDE filename to the hash table */
hash = computeHash((const char*)ptr + kCDELen, fileNameLen);
addToHash(pArchive, (const char*)ptr + kCDELen, fileNameLen, hash);
localHdr = basePtr + localHdrOffset;
if (get4LE(localHdr) != kLFHSignature) {
LOGW("Bad offset to local header: %d (at %d)\n",
localHdrOffset, i);
goto bail;
}
ptr += kCDELen + fileNameLen + extraLen + commentLen;
CHECK_OFFSET(ptr - basePtr);
}
result = true;
bail:
return result;
#undef CHECK_OFFSET
}
/*
* Parses the Zip archive's Central Directory. Allocates and populates the
* hash table.
*
* Returns 0 on success.
*/
static int parseZipArchive(ZipArchive* pArchive)
{
int result = -1;
const u1* cdPtr = (const u1*)pArchive->mDirectoryMap.addr;
size_t cdLength = pArchive->mDirectoryMap.length;
int numEntries = pArchive->mNumEntries;
/*
* Create hash table. We have a minimum 75% load factor, possibly as
* low as 50% after we round off to a power of 2. There must be at
* least one unused entry to avoid an infinite loop during creation.
*/
pArchive->mHashTableSize = dexRoundUpPower2(1 + (numEntries * 4) / 3);
pArchive->mHashTable = (ZipHashEntry*)
calloc(pArchive->mHashTableSize, sizeof(ZipHashEntry));
/*
* Walk through the central directory, adding entries to the hash
* table and verifying values.
*/
const u1* ptr = cdPtr;
int i;
for (i = 0; i < numEntries; i++) {
if (get4LE(ptr) != kCDESignature) {
LOGW("Zip: missed a central dir sig (at %d)\n", i);
goto bail;
}
if (ptr + kCDELen > cdPtr + cdLength) {
LOGW("Zip: ran off the end (at %d)\n", i);
goto bail;
}
long localHdrOffset = (long) get4LE(ptr + kCDELocalOffset);
if (localHdrOffset >= pArchive->mDirectoryOffset) {
LOGW("Zip: bad LFH offset %ld at entry %d\n", localHdrOffset, i);
goto bail;
}
unsigned int fileNameLen, extraLen, commentLen, hash;
fileNameLen = get2LE(ptr + kCDENameLen);
extraLen = get2LE(ptr + kCDEExtraLen);
commentLen = get2LE(ptr + kCDECommentLen);
/* add the CDE filename to the hash table */
hash = computeHash((const char*)ptr + kCDELen, fileNameLen);
addToHash(pArchive, (const char*)ptr + kCDELen, fileNameLen, hash);
ptr += kCDELen + fileNameLen + extraLen + commentLen;
if ((size_t)(ptr - cdPtr) > cdLength) {
LOGW("Zip: bad CD advance (%d vs %zd) at entry %d\n",
(int) (ptr - cdPtr), cdLength, i);
goto bail;
}
}
LOGV("+++ zip good scan %d entries\n", numEntries);
result = 0;
bail:
return result;
}
/*
* Parses the Zip archive's Central Directory. Allocates and populates the
* hash table.
*
* Returns 0 on success.
*/
static int parseZipArchive(ZipArchive* pArchive)
{
int result = -1;
const u1* cdPtr = (const u1*)pArchive->mDirectoryMap.addr;
size_t cdLength = pArchive->mDirectoryMap.length;
int numEntries = pArchive->mNumEntries;
/*
* Create hash table. We have a minimum 75% load factor, possibly as
* low as 50% after we round off to a power of 2. There must be at
* least one unused entry to avoid an infinite loop during creation.
*/
pArchive->mHashTableSize = dexRoundUpPower2(1 + (numEntries * 4) / 3);
pArchive->mHashTable = (ZipHashEntry*)
calloc(pArchive->mHashTableSize, sizeof(ZipHashEntry));
/*
* Walk through the central directory, adding entries to the hash
* table and verifying values.
*/
const u1* ptr = cdPtr;
int i;
for (i = 0; i < numEntries; i++) {
if (get4LE(ptr) != kCDESignature) {
ALOGW("Zip: missed a central dir sig (at %d)", i);
goto bail;
}
if (ptr + kCDELen > cdPtr + cdLength) {
ALOGW("Zip: ran off the end (at %d)", i);
goto bail;
}
long localHdrOffset = (long) get4LE(ptr + kCDELocalOffset);
if (localHdrOffset >= pArchive->mDirectoryOffset) {
ALOGW("Zip: bad LFH offset %ld at entry %d", localHdrOffset, i);
goto bail;
}
unsigned int gpbf = get2LE(ptr + kCDEGPBFlags);
if ((gpbf & kGPFUnsupportedMask) != 0) {
ALOGW("Invalid General Purpose Bit Flag: %d", gpbf);
goto bail;
}
unsigned int nameLen, extraLen, commentLen, hash;
nameLen = get2LE(ptr + kCDENameLen);
extraLen = get2LE(ptr + kCDEExtraLen);
commentLen = get2LE(ptr + kCDECommentLen);
const char *name = (const char *) ptr + kCDELen;
/* Check name for NULL characters */
if (memchr(name, 0, nameLen) != NULL) {
ALOGW("Filename contains NUL byte");
goto bail;
}
/* add the CDE filename to the hash table */
hash = computeHash(name, nameLen);
addToHash(pArchive, name, nameLen, hash);
/* We don't care about the comment or extra data. */
ptr += kCDELen + nameLen + extraLen + commentLen;
if ((size_t)(ptr - cdPtr) > cdLength) {
ALOGW("Zip: bad CD advance (%d vs %zd) at entry %d",
(int) (ptr - cdPtr), cdLength, i);
goto bail;
}
}
ALOGV("+++ zip good scan %d entries", numEntries);
result = 0;
bail:
return result;
}
