/*
* Copyright 2006 The Android Open Source Project
*
* Simple Zip file support.
*/
#include "safe_iop.h"
#include "zlib.h"
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdint.h> // for uintptr_t
#include <stdlib.h>
#include <sys/stat.h> // for S_ISLNK()
#include <unistd.h>
#define LOG_TAG "minzip"
#include "Zip.h"
#include "Bits.h"
#include "Log.h"
#include "DirUtil.h"
#undef NDEBUG // do this after including Log.h
#include <assert.h>
#define SORT_ENTRIES 1
/*
* Offset and length constants (java.util.zip naming convention).
*/
enum {
CENSIG = 0x02014b50, // PK12
CENHDR = 46,
CENVEM = 4,
CENVER = 6,
CENFLG = 8,
CENHOW = 10,
CENTIM = 12,
CENCRC = 16,
CENSIZ = 20,
CENLEN = 24,
CENNAM = 28,
CENEXT = 30,
CENCOM = 32,
CENDSK = 34,
CENATT = 36,
CENATX = 38,
CENOFF = 42,
ENDSIG = 0x06054b50, // PK56
ENDHDR = 22,
ENDSUB = 8,
ENDTOT = 10,
ENDSIZ = 12,
ENDOFF = 16,
ENDCOM = 20,
EXTSIG = 0x08074b50, // PK78
EXTHDR = 16,
EXTCRC = 4,
EXTSIZ = 8,
EXTLEN = 12,
LOCSIG = 0x04034b50, // PK34
LOCHDR = 30,
LOCVER = 4,
LOCFLG = 6,
LOCHOW = 8,
LOCTIM = 10,
LOCCRC = 14,
LOCSIZ = 18,
LOCLEN = 22,
LOCNAM = 26,
LOCEXT = 28,
STORED = 0,
DEFLATED = 8,
CENVEM_UNIX = 3 << 8, // the high byte of CENVEM
};
/*
* For debugging, dump the contents of a ZipEntry.
*/
#if 0
static void dumpEntry(const ZipEntry* pEntry)
{
LOGI(" %p '%.*s'\n", pEntry->fileName,pEntry->fileNameLen,pEntry->fileName);
LOGI(" off=%ld comp=%ld uncomp=%ld how=%d\n", pEntry->offset,
pEntry->compLen, pEntry->uncompLen, pEntry->compression);
}
#endif
/*
* (This is a mzHashTableLookup callback.)
*
* Compare two ZipEntry structs, by name.
*/
static int hashcmpZipEntry(const void* ventry1, const void* ventry2)
{
const ZipEntry* entry1 = (const ZipEntry*) ventry1;
const ZipEntry* entry2 = (const ZipEntry*) ventry2;
if (entry1->fileNameLen != entry2->fileNameLen)
return entry1->fileNameLen - entry2->fileNameLen;
return memcmp(entry1->fileName, entry2->fileName, entry1->fileNameLen);
}
/*
* (This is a mzHashTableLookup callback.)
*
* find a ZipEntry struct by name.
*/
static int hashcmpZipName(const void* ventry, const void* vname)
{
const ZipEntry* entry = (const ZipEntry*) ventry;
const char* name = (const char*) vname;
unsigned int nameLen = strlen(name);
if (entry->fileNameLen != nameLen)
return entry->fileNameLen - nameLen;
return memcmp(entry->fileName, name, nameLen);
}
/*
* Compute the hash code for a ZipEntry filename.
*
* Not expected to be compatible with any other hash function, so we init
* to 2 to ensure it doesn't happen to match.
*/
static unsigned int computeHash(const char* name, int nameLen)
{
unsigned int hash = 2;
while (nameLen--)
hash = hash * 31 + *name++;
return hash;
}
static void addEntryToHashTable(HashTable* pHash, ZipEntry* pEntry)
{
unsigned int itemHash = computeHash(pEntry->fileName, pEntry->fileNameLen);
const ZipEntry* found;
found = (const ZipEntry*)mzHashTableLookup(pHash,
itemHash, pEntry, hashcmpZipEntry, true);
if (found != pEntry) {
LOGW("WARNING: duplicate entry '%.*s' in Zip\n",
found->fileNameLen, found->fileName);
/* keep going */
}
}
static int validFilename(const char *fileName, unsigned int fileNameLen)
{
// Forbid super long filenames.
if (fileNameLen >= PATH_MAX) {
LOGW("Filename too long (%d chatacters)\n", fileNameLen);
return 0;
}
// Require all characters to be printable ASCII (no NUL, no UTF-8, etc).
unsigned int i;
for (i = 0; i < fileNameLen; ++i) {
if (fileName[i] < 32 || fileName[i] >= 127) {
LOGW("Filename contains invalid character '\%03o'\n", fileName[i]);
return 0;
}
}
return 1;
}
/*
* Parse the contents of a Zip archive. After confirming that the file
* is in fact a Zip, we scan out the contents of the central directory and
* store it in a hash table.
*
* Returns "true" on success.
*/
static bool parseZipArchive(ZipArchive* pArchive)
{
bool result = false;
const unsigned char* ptr;
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 (LOCSIG) or, if the archive doesn't
* have any files in it, the end-of-central-directory signature (ENDSIG).
*/
val = get4LE(pArchive->addr);
if (val == ENDSIG) {
LOGI("Found Zip archive, but it looks empty\n");
goto bail;
} else if (val != LOCSIG) {
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 = pArchive->addr + pArchive->length - ENDHDR;
while (ptr >= (const unsigned char*) pArchive->addr) {
if (*ptr == (ENDSIG & 0xff) && get4LE(ptr) == ENDSIG)
break;
ptr--;
}
if (ptr < (const unsigned char*) pArchive->addr) {
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.
*/
numEntries = get2LE(ptr + ENDSUB);
cdOffset = get4LE(ptr + ENDOFF);
LOGVV("numEntries=%d cdOffset=%d\n", numEntries, cdOffset);
if (numEntries == 0 || cdOffset >= pArchive->length) {
LOGW("Invalid entries=%d offset=%d (len=%zd)\n",
numEntries, cdOffset, pArchive->length);
goto bail;
}
/*
* Create data structures to hold entries.
*/
pArchive->numEntries = numEntries;
pArchive->pEntries = (ZipEntry*) calloc(numEntries, sizeof(ZipEntry));
pArchive->pHash = mzHashTableCreate(mzHashSize(numEntries), NULL);
if (pArchive->pEntries == NULL || pArchive->pHash == NULL)
goto bail;
ptr = pArchive->addr + cdOffset;
for (i = 0; i < numEntries; i++) {
ZipEntry* pEntry;
unsigned int fileNameLen, extraLen, commentLen, localHdrOffset;
const unsigned char* localHdr;
const char *fileName;
if (ptr + CENHDR > (const unsigned char*)pArchive->addr + pArchive->length) {
LOGW("Ran off the end (at %d)\n", i);
goto bail;
}
if (get4LE(ptr) != CENSIG) {
LOGW("Missed a central dir sig (at %d)\n", i);
goto bail;
}
localHdrOffset = get4LE(ptr + CENOFF);
fileNameLen = get2LE(ptr + CENNAM);
extraLen = get2LE(ptr + CENEXT);
commentLen = get2LE(ptr + CENCOM);
fileName = (const char*)ptr + CENHDR;
if (fileName + fileNameLen > (const char*)pArchive->addr + pArchive->length) {
LOGW("Filename ran off the end (at %d)\n", i);
goto bail;
}
if (!validFilename(fileName, fileNameLen)) {
LOGW("Invalid filename (at %d)\n", i);
goto bail;
}
#if SORT_ENTRIES
/* Figure out where this entry should go (binary search).
*/
if (i > 0) {
int low, high;
low = 0;
high = i - 1;
while (low <= high) {
int mid;
int diff;
int diffLen;
mid = low + ((high - low) / 2); // avoid overflow
if (pArchive->pEntries[mid].fileNameLen < fileNameLen) {
diffLen = pArchive->pEntries[mid].fileNameLen;
} else {
diffLen = fileNameLen;
}
diff = strncmp(pArchive->pEntries[mid].fileName, fileName,
diffLen);
if (diff == 0) {
diff = pArchive->pEntries[mid].fileNameLen - fileNameLen;
}
if (diff < 0) {
low = mid + 1;
} else if (diff > 0) {
high = mid - 1;
} else {
high = mid;
break;
}
}
unsigned int target = high + 1;
assert(target <= i);
if (target != i) {
/* It belongs somewhere other than at the end of
* the list. Make some room at [target].
*/
memmove(pArchive->pEntries + target + 1,
pArchive->pEntries + target,
(i - target) * sizeof(ZipEntry));
}
pEntry = &pArchive->pEntries[target];
} else {
pEntry = &pArchive->pEntries[0];
}
#else
pEntry = &pArchive->pEntries[i];
#endif
//LOGI("%d: localHdr=%d fnl=%d el=%d cl=%d\n",
// i, localHdrOffset, fileNameLen, extraLen, commentLen);
pEntry->fileNameLen = fileNameLen;
pEntry->fileName = fileName;
pEntry->compLen = get4LE(ptr + CENSIZ);
pEntry->uncompLen = get4LE(ptr + CENLEN);
pEntry->compression = get2LE(ptr + CENHOW);
pEntry->modTime = get4LE(ptr + CENTIM);
pEntry->crc32 = get4LE(ptr + CENCRC);
/* These two are necessary for finding the mode of the file.
*/
pEntry->versionMadeBy = get2LE(ptr + CENVEM);
if ((pEntry->versionMadeBy & 0xff00) != 0 &&
(pEntry->versionMadeBy & 0xff00) != CENVEM_UNIX)
{
LOGW("Incompatible \"version made by\": 0x%02x (at %d)\n",
pEntry->versionMadeBy >> 8, i);
goto bail;
}
pEntry->externalFileAttributes = get4LE(ptr + CENATX);
// Perform pArchive->addr + localHdrOffset, ensuring that it won't
// overflow. This is needed because localHdrOffset is untrusted.
if (!safe_add((uintptr_t *)&localHdr, (uintptr_t)pArchive->addr,
(uintptr_t)localHdrOffset)) {
LOGW("Integer overflow adding in parseZipArchive\n");
goto bail;
}
if ((uintptr_t)localHdr + LOCHDR >
(uintptr_t)pArchive->addr + pArchive->length) {
LOGW("Bad offset to local header: %d (at %d)\n", localHdrOffset, i);
goto bail;
}
if (get4LE(localHdr) != LOCSIG) {
LOGW("Missed a local header sig (at %d)\n", i);
goto bail;
}
pEntry->offset = localHdrOffset + LOCHDR
+ get2LE(localHdr + LOCNAM) + get2LE(localHdr + LOCEXT);
if (!safe_add(NULL, pEntry->offset, pEntry->compLen)) {
LOGW("Integer overflow adding in parseZipArchive\n");
goto bail;
}
if ((size_t)pEntry->offset + pEntry->compLen > pArchive->length) {
LOGW("Data ran off the end (at %d)\n", i);
goto bail;
}
#if !SORT_ENTRIES
/* Add to hash table; no need to lock here.
* Can't do this now if we're sorting, because entries
* will move around.
*/
addEntryToHashTable(pArchive->pHash, pEntry);
#endif
//dumpEntry(pEntry);
ptr += CENHDR + fileNameLen + extraLen + commentLen;
}
#if SORT_ENTRIES
/* If we're sorting, we have to wait until all entries
* are in their final places, otherwise the pointers will
* probably point to the wrong things.
*/
for (i = 0; i < numEntries; i++) {
/* Add to hash table; no need to lock here.
*/
addEntryToHashTable(pArchive->pHash, &pArchive->pEntries[i]);
}
#endif
result = true;
bail:
if (!result) {
mzHashTableFree(pArchive->pHash);
pArchive->pHash = NULL;
}
return result;
}
/*
* Open a Zip archive and scan out the contents.
*
* The easiest way to do this is to mmap() the whole thing and do the
* traditional backward scan for central directory. Since the EOCD is
* a relatively small bit at the end, we should end up only touching a
* small set of pages.
*
* This will be called on non-Zip files, especially during startup, so
* we don't want to be too noisy about failures. (Do we want a "quiet"
* flag?)
*
* On success, we fill out the contents of "pArchive".
*/
int mzOpenZipArchive(unsigned char* addr, size_t length, ZipArchive* pArchive)
{
int err;
if (length < ENDHDR) {
err = -1;
LOGV("File '%s' too small to be zip (%zd)\n", fileName, map.length);
goto bail;
}
pArchive->addr = addr;
pArchive->length = length;
if (!parseZipArchive(pArchive)) {
err = -1;
LOGV("Parsing '%s' failed\n", fileName);
goto bail;
}
err = 0;
bail:
if (err != 0)
mzCloseZipArchive(pArchive);
return err;
}
/*
* Close a ZipArchive, closing the file and freeing the contents.
*
* NOTE: the ZipArchive may not have been fully created.
*/
void mzCloseZipArchive(ZipArchive* pArchive)
{
LOGV("Closing archive %p\n", pArchive);
free(pArchive->pEntries);
mzHashTableFree(pArchive->pHash);
pArchive->pHash = NULL;
pArchive->pEntries = NULL;
}
/*
* Find a matching entry.
*
* Returns NULL if no matching entry found.
*/
const ZipEntry* mzFindZipEntry(const ZipArchive* pArchive,
const char* entryName)
{
unsigned int itemHash = computeHash(entryName, strlen(entryName));
return (const ZipEntry*)mzHashTableLookup(pArchive->pHash,
itemHash, (char*) entryName, hashcmpZipName, false);
}
/*
* Return true if the entry is a symbolic link.
*/
bool mzIsZipEntrySymlink(const ZipEntry* pEntry)
{
if ((pEntry->versionMadeBy & 0xff00) == CENVEM_UNIX) {
return S_ISLNK(pEntry->externalFileAttributes >> 16);
}
return false;
}
/* Call processFunction on the uncompressed data of a STORED entry.
*/
static bool processStoredEntry(const ZipArchive *pArchive,
const ZipEntry *pEntry, ProcessZipEntryContentsFunction processFunction,
void *cookie)
{
return processFunction(pArchive->addr + pEntry->offset, pEntry->uncompLen, cookie);
}
static bool processDeflatedEntry(const ZipArchive *pArchive,
const ZipEntry *pEntry, ProcessZipEntryContentsFunction processFunction,
void *cookie)
{
long result = -1;
unsigned char readBuf[32 * 1024];
unsigned char procBuf[32 * 1024];
z_stream zstream;
int zerr;
long compRemaining;
compRemaining = pEntry->compLen;
/*
* Initialize the zlib stream.
*/
memset(&zstream, 0, sizeof(zstream));
zstream.zalloc = Z_NULL;
zstream.zfree = Z_NULL;
zstream.opaque = Z_NULL;
zstream.next_in = pArchive->addr + pEntry->offset;
zstream.avail_in = pEntry->compLen;
zstream.next_out = (Bytef*) procBuf;
zstream.avail_out = sizeof(procBuf);
zstream.data_type = Z_UNKNOWN;
/*
* Use the undocumented "negative window bits" feature to tell zlib
* that there's no zlib header waiting for it.
*/
zerr = inflateInit2(&zstream, -MAX_WBITS);
if (zerr != Z_OK) {
if (zerr == Z_VERSION_ERROR) {
LOGE("Installed zlib is not compatible with linked version (%s)\n",
ZLIB_VERSION);
} else {
LOGE("Call to inflateInit2 failed (zerr=%d)\n", zerr);
}
goto bail;
}
/*
* Loop while we have data.
*/
do {
/* uncompress the data */
zerr = inflate(&zstream, Z_NO_FLUSH);
if (zerr != Z_OK && zerr != Z_STREAM_END) {
LOGD("zlib inflate call failed (zerr=%d)\n", zerr);
goto z_bail;
}
/* write when we're full or when we're done */
if (zstream.avail_out == 0 ||
(zerr == Z_STREAM_END && zstream.avail_out != sizeof(procBuf)))
{
long procSize = zstream.next_out - procBuf;
LOGVV("+++ processing %d bytes\n", (int) procSize);
bool ret = processFunction(procBuf, procSize, cookie);
if (!ret) {
LOGW("Process function elected to fail (in inflate)\n");
goto z_bail;
}
zstream.next_out = procBuf;
zstream.avail_out = sizeof(procBuf);
}
} while (zerr == Z_OK);
assert(zerr == Z_STREAM_END); /* other errors should've been caught */
// success!
result = zstream.total_out;
z_bail:
inflateEnd(&zstream); /* free up any allocated structures */
bail:
if (result != pEntry->uncompLen) {
if (result != -1) // error already shown?
LOGW("Size mismatch on inflated file (%ld vs %ld)\n",
result, pEntry->uncompLen);
return false;
}
return true;
}
/*
* Stream the uncompressed data through the supplied function,
* passing cookie to it each time it gets called. processFunction
* may be called more than once.
*
* If processFunction returns false, the operation is abandoned and
* mzProcessZipEntryContents() immediately returns false.
*
* This is useful for calculating the hash of an entry's uncompressed contents.
*/
bool mzProcessZipEntryContents(const ZipArchive *pArchive,
const ZipEntry *pEntry, ProcessZipEntryContentsFunction processFunction,
void *cookie)
{
bool ret = false;
off_t oldOff;
switch (pEntry->compression) {
case STORED:
ret = processStoredEntry(pArchive, pEntry, processFunction, cookie);
break;
case DEFLATED:
ret = processDeflatedEntry(pArchive, pEntry, processFunction, cookie);
break;
default:
LOGE("Unsupported compression type %d for entry '%s'\n",
pEntry->compression, pEntry->fileName);
break;
}
return ret;
}
static bool crcProcessFunction(const unsigned char *data, int dataLen,
void *crc)
{
*(unsigned long *)crc = crc32(*(unsigned long *)crc, data, dataLen);
return true;
}
/*
* Check the CRC on this entry; return true if it is correct.
* May do other internal checks as well.
*/
bool mzIsZipEntryIntact(const ZipArchive *pArchive, const ZipEntry *pEntry)
{
unsigned long crc;
bool ret;
crc = crc32(0L, Z_NULL, 0);
ret = mzProcessZipEntryContents(pArchive, pEntry, crcProcessFunction,
(void *)&crc);
if (!ret) {
LOGE("Can't calculate CRC for entry\n");
return false;
}
if (crc != (unsigned long)pEntry->crc32) {
LOGW("CRC for entry %.*s (0x%08lx) != expected (0x%08lx)\n",
pEntry->fileNameLen, pEntry->fileName, crc, pEntry->crc32);
return false;
}
return true;
}
typedef struct {
char *buf;
int bufLen;
} CopyProcessArgs;
static bool copyProcessFunction(const unsigned char *data, int dataLen,
void *cookie)
{
CopyProcessArgs *args = (CopyProcessArgs *)cookie;
if (dataLen <= args->bufLen) {
memcpy(args->buf, data, dataLen);
args->buf += dataLen;
args->bufLen -= dataLen;
return true;
}
return false;
}
/*
* Read an entry into a buffer allocated by the caller.
*/
bool mzReadZipEntry(const ZipArchive* pArchive, const ZipEntry* pEntry,
char *buf, int bufLen)
{
CopyProcessArgs args;
bool ret;
args.buf = buf;
args.bufLen = bufLen;
ret = mzProcessZipEntryContents(pArchive, pEntry, copyProcessFunction,
(void *)&args);
if (!ret) {
LOGE("Can't extract entry to buffer.\n");
return false;
}
return true;
}
static bool writeProcessFunction(const unsigned char *data, int dataLen,
void *cookie)
{
int fd = (int)(intptr_t)cookie;
ssize_t soFar = 0;
while (true) {
ssize_t n = write(fd, data+soFar, dataLen-soFar);
if (n <= 0) {
LOGE("Error writing %ld bytes from zip file from %p: %s\n",
dataLen-soFar, data+soFar, strerror(errno));
if (errno != EINTR) {
return false;
}
} else if (n > 0) {
soFar += n;
if (soFar == dataLen) return true;
if (soFar > dataLen) {
LOGE("write overrun? (%ld bytes instead of %d)\n",
soFar, dataLen);
return false;
}
}
}
}
/*
* Uncompress "pEntry" in "pArchive" to "fd" at the current offset.
*/
bool mzExtractZipEntryToFile(const ZipArchive *pArchive,
const ZipEntry *pEntry, int fd)
{
bool ret = mzProcessZipEntryContents(pArchive, pEntry, writeProcessFunction,
(void*)(intptr_t)fd);
if (!ret) {
LOGE("Can't extract entry to file.\n");
return false;
}
return true;
}
typedef struct {
unsigned char* buffer;
long len;
} BufferExtractCookie;
static bool bufferProcessFunction(const unsigned char *data, int dataLen,
void *cookie) {
BufferExtractCookie *bec = (BufferExtractCookie*)cookie;
memmove(bec->buffer, data, dataLen);
bec->buffer += dataLen;
bec->len -= dataLen;
return true;
}
/*
* Uncompress "pEntry" in "pArchive" to buffer, which must be large
* enough to hold mzGetZipEntryUncomplen(pEntry) bytes.
*/
bool mzExtractZipEntryToBuffer(const ZipArchive *pArchive,
const ZipEntry *pEntry, unsigned char *buffer)
{
BufferExtractCookie bec;
bec.buffer = buffer;
bec.len = mzGetZipEntryUncompLen(pEntry);
bool ret = mzProcessZipEntryContents(pArchive, pEntry,
bufferProcessFunction, (void*)&bec);
if (!ret || bec.len != 0) {
LOGE("Can't extract entry to memory buffer.\n");
return false;
}
return true;
}
/* Helper state to make path translation easier and less malloc-happy.
*/
typedef struct {
const char *targetDir;
const char *zipDir;
char *buf;
int targetDirLen;
int zipDirLen;
int bufLen;
} MzPathHelper;
/* Given the values of targetDir and zipDir in the helper,
* return the target filename of the provided entry.
* The helper must be initialized first.
*/
static const char *targetEntryPath(MzPathHelper *helper, ZipEntry *pEntry)
{
int needLen;
bool firstTime = (helper->buf == NULL);
/* target file <-- targetDir + / + entry[zipDirLen:]
*/
needLen = helper->targetDirLen + 1 +
pEntry->fileNameLen - helper->zipDirLen + 1;
if (needLen > helper->bufLen) {
char *newBuf;
needLen *= 2;
newBuf = (char *)realloc(helper->buf, needLen);
if (newBuf == NULL) {
return NULL;
}
helper->buf = newBuf;
helper->bufLen = needLen;
}
/* Every path will start with the target path and a slash.
*/
if (firstTime) {
char *p = helper->buf;
memcpy(p, helper->targetDir, helper->targetDirLen);
p += helper->targetDirLen;
if (p == helper->buf || p[-1] != '/') {
helper->targetDirLen += 1;
*p++ = '/';
}
}
/* Replace the custom part of the path with the appropriate
* part of the entry's path.
*/
char *epath = helper->buf + helper->targetDirLen;
memcpy(epath, pEntry->fileName + helper->zipDirLen,
pEntry->fileNameLen - helper->zipDirLen);
epath += pEntry->fileNameLen - helper->zipDirLen;
*epath = '\0';
return helper->buf;
}
/*
* Inflate all entries under zipDir to the directory specified by
* targetDir, which must exist and be a writable directory.
*
* The immediate children of zipDir will become the immediate
* children of targetDir; e.g., if the archive contains the entries
*
* a/b/c/one
* a/b/c/two
* a/b/c/d/three
*
* and mzExtractRecursive(a, "a/b/c", "/tmp") is called, the resulting
* files will be
*
* /tmp/one
* /tmp/two
* /tmp/d/three
*
* Returns true on success, false on failure.
*/
bool mzExtractRecursive(const ZipArchive *pArchive,
const char *zipDir, const char *targetDir,
int flags, const struct utimbuf *timestamp,
void (*callback)(const char *fn, void *), void *cookie,
struct selabel_handle *sehnd)
{
if (zipDir[0] == '/') {
LOGE("mzExtractRecursive(): zipDir must be a relative path.\n");
return false;
}
if (targetDir[0] != '/') {
LOGE("mzExtractRecursive(): targetDir must be an absolute path.\n");
return false;
}
unsigned int zipDirLen;
char *zpath;
zipDirLen = strlen(zipDir);
zpath = (char *)malloc(zipDirLen + 2);
if (zpath == NULL) {
LOGE("Can't allocate %d bytes for zip path\n", zipDirLen + 2);
return false;
}
/* If zipDir is empty, we'll extract the entire zip file.
* Otherwise, canonicalize the path.
*/
if (zipDirLen > 0) {
/* Make sure there's (hopefully, exactly one) slash at the
* end of the path. This way we don't need to worry about
* accidentally extracting "one/twothree" when a path like
* "one/two" is specified.
*/
memcpy(zpath, zipDir, zipDirLen);
if (zpath[zipDirLen-1] != '/') {
zpath[zipDirLen++] = '/';
}
}
zpath[zipDirLen] = '\0';
/* Set up the helper structure that we'll use to assemble paths.
*/
MzPathHelper helper;
helper.targetDir = targetDir;
helper.targetDirLen = strlen(helper.targetDir);
helper.zipDir = zpath;
helper.zipDirLen = strlen(helper.zipDir);
helper.buf = NULL;
helper.bufLen = 0;
/* Walk through the entries and extract anything whose path begins
* with zpath.
//TODO: since the entries are sorted, binary search for the first match
// and stop after the first non-match.
*/
unsigned int i;
bool seenMatch = false;
int ok = true;
int extractCount = 0;
for (i = 0; i < pArchive->numEntries; i++) {
ZipEntry *pEntry = pArchive->pEntries + i;
if (pEntry->fileNameLen < zipDirLen) {
//TODO: look out for a single empty directory entry that matches zpath, but
// missing the trailing slash. Most zip files seem to include
// the trailing slash, but I think it's legal to leave it off.
// e.g., zpath "a/b/", entry "a/b", with no children of the entry.
/* No chance of matching.
*/
#if SORT_ENTRIES
if (seenMatch) {
/* Since the entries are sorted, we can give up
* on the first mismatch after the first match.
*/
break;
}
#endif
continue;
}
/* If zpath is empty, this strncmp() will match everything,
* which is what we want.
*/
if (strncmp(pEntry->fileName, zpath, zipDirLen) != 0) {
#if SORT_ENTRIES
if (seenMatch) {
/* Since the entries are sorted, we can give up
* on the first mismatch after the first match.
*/
break;
}
#endif
continue;
}
/* This entry begins with zipDir, so we'll extract it.
*/
seenMatch = true;
/* Find the target location of the entry.
*/
const char *targetFile = targetEntryPath(&helper, pEntry);
if (targetFile == NULL) {
LOGE("Can't assemble target path for \"%.*s\"\n",
pEntry->fileNameLen, pEntry->fileName);
ok = false;
break;
}
/* With DRY_RUN set, invoke the callback but don't do anything else.
*/
if (flags & MZ_EXTRACT_DRY_RUN) {
if (callback != NULL) callback(targetFile, cookie);
continue;
}
/* Create the file or directory.
*/
#define UNZIP_DIRMODE 0755
#define UNZIP_FILEMODE 0644
if (pEntry->fileName[pEntry->fileNameLen-1] == '/') {
if (!(flags & MZ_EXTRACT_FILES_ONLY)) {
int ret = dirCreateHierarchy(
targetFile, UNZIP_DIRMODE, timestamp, false, sehnd);
if (ret != 0) {
LOGE("Can't create containing directory for \"%s\": %s\n",
targetFile, strerror(errno));
ok = false;
break;
}
LOGD("Extracted dir \"%s\"\n", targetFile);
}
} else {
/* This is not a directory. First, make sure that
* the containing directory exists.
*/
int ret = dirCreateHierarchy(
targetFile, UNZIP_DIRMODE, timestamp, true, sehnd);
if (ret != 0) {
LOGE("Can't create containing directory for \"%s\": %s\n",
targetFile, strerror(errno));
ok = false;
break;
}
/* With FILES_ONLY set, we need to ignore metadata entirely,
* so treat symlinks as regular files.
*/
if (!(flags & MZ_EXTRACT_FILES_ONLY) && mzIsZipEntrySymlink(pEntry)) {
/* The entry is a symbolic link.
* The relative target of the symlink is in the
* data section of this entry.
*/
if (pEntry->uncompLen == 0) {
LOGE("Symlink entry \"%s\" has no target\n",
targetFile);
ok = false;
break;
}
char *linkTarget = malloc(pEntry->uncompLen + 1);
if (linkTarget == NULL) {
ok = false;
break;
}
ok = mzReadZipEntry(pArchive, pEntry, linkTarget,
pEntry->uncompLen);
if (!ok) {
LOGE("Can't read symlink target for \"%s\"\n",
targetFile);
free(linkTarget);
break;
}
linkTarget[pEntry->uncompLen] = '\0';
/* Make the link.
*/
ret = symlink(linkTarget, targetFile);
if (ret != 0) {
LOGE("Can't symlink \"%s\" to \"%s\": %s\n",
targetFile, linkTarget, strerror(errno));
free(linkTarget);
ok = false;
break;
}
LOGD("Extracted symlink \"%s\" -> \"%s\"\n",
targetFile, linkTarget);
free(linkTarget);
} else {
/* The entry is a regular file.
* Open the target for writing.
*/
char *secontext = NULL;
if (sehnd) {
selabel_lookup(sehnd, &secontext, targetFile, UNZIP_FILEMODE);
setfscreatecon(secontext);
}
int fd = creat(targetFile, UNZIP_FILEMODE);
if (secontext) {
freecon(secontext);
setfscreatecon(NULL);
}
if (fd < 0) {
LOGE("Can't create target file \"%s\": %s\n",
targetFile, strerror(errno));
ok = false;
break;
}
bool ok = mzExtractZipEntryToFile(pArchive, pEntry, fd);
close(fd);
if (!ok) {
LOGE("Error extracting \"%s\"\n", targetFile);
ok = false;
break;
}
if (timestamp != NULL && utime(targetFile, timestamp)) {
LOGE("Error touching \"%s\"\n", targetFile);
ok = false;
break;
}
LOGV("Extracted file \"%s\"\n", targetFile);
++extractCount;
}
}
if (callback != NULL) callback(targetFile, cookie);
}
LOGD("Extracted %d file(s)\n", extractCount);
free(helper.buf);
free(zpath);
return ok;
}
