static int
find_file(int fd, zentry *entry, const char *file_name)
{
int bytes;
int res;
int entry_size;
int read_size;
int base_offset;
Byte *p;
Byte *bp;
Byte *buffer;
Byte locbuf[LOCHDR];
if ((buffer = (Byte*)malloc(BUFSIZE)) == NULL) {
return(-1);
}
p = buffer;
bp = buffer;
/*
* Read the END Header, which is the starting point for ZIP files.
* (Clearly designed to make writing a zip file easier than reading
* one. Now isn't that precious...)
*/
if ((base_offset = find_end(fd, bp)) == -1) {
free(buffer);
return (-1);
}
/*
* There is a historical, but undocumented, ability to allow for
* additional "stuff" to be prepended to the zip/jar file. It seems
* that this has been used to prepend an actual java launcher
* executable to the jar on Windows. Although this is just another
* form of statically linking a small piece of the JVM to the
* application, we choose to continue to support it. Note that no
* guarantees have been made (or should be made) to the customer that
* this will continue to work.
*
* Therefore, calculate the base offset of the zip file (within the
* expanded file) by assuming that the central directory is followed
* immediately by the end record.
*/
base_offset = base_offset - ENDSIZ(p) - ENDOFF(p);
/*
* The END Header indicates the start of the Central Directory
* Headers. Remember that the desired Central Directory Header (CEN)
* will almost always be the second one and the first one is a small
* directory entry ("META-INF/"). Keep the code optimized for
* that case.
*
* Begin by seeking to the beginning of the Central Directory and
* reading in the first buffer full of bits.
*/
if (lseek(fd, base_offset + ENDOFF(p), SEEK_SET) < (off_t)0) {
free(buffer);
return (-1);
}
if ((bytes = read(fd, bp, MINREAD)) < 0) {
free(buffer);
return (-1);
}
/*
* Loop through the Central Directory Headers. Note that a valid zip/jar
* must have an ENDHDR (with ENDSIG) after the Central Directory.
*/
while (GETSIG(p) == CENSIG) {
/*
* If a complete header isn't in the buffer, shift the contents
* of the buffer down and refill the buffer. Note that the check
* for "bytes < CENHDR" must be made before the test for the entire
* size of the header, because if bytes is less than CENHDR, the
* actual size of the header can't be determined. The addition of
* SIGSIZ guarantees that the next signature is also in the buffer
* for proper loop termination.
*/
if (bytes < CENHDR) {
p = memmove(bp, p, bytes);
if ((res = read(fd, bp + bytes, MINREAD)) <= 0) {
free(buffer);
return (-1);
}
bytes += res;
}
entry_size = CENHDR + CENNAM(p) + CENEXT(p) + CENCOM(p);
if (bytes < entry_size + SIGSIZ) {
if (p != bp)
p = memmove(bp, p, bytes);
read_size = entry_size - bytes + SIGSIZ;
read_size = (read_size < MINREAD) ? MINREAD : read_size;
if ((res = read(fd, bp + bytes, read_size)) <= 0) {
free(buffer);
return (-1);
}
bytes += res;
}
/*
* Check if the name is the droid we are looking for; the jar file
* manifest. If so, build the entry record from the data found in
* the header located and return success.
*/
if (CENNAM(p) == strlen(file_name) &&
memcmp((p + CENHDR), file_name, strlen(file_name)) == 0) {
if (lseek(fd, base_offset + CENOFF(p), SEEK_SET) < (off_t)0) {
free(buffer);
return (-1);
}
if (read(fd, locbuf, LOCHDR) < 0) {
free(buffer);
return (-1);
}
if (GETSIG(locbuf) != LOCSIG) {
free(buffer);
return (-1);
}
entry->isize = CENLEN(p);
entry->csize = CENSIZ(p);
entry->offset = base_offset + CENOFF(p) + LOCHDR +
LOCNAM(locbuf) + LOCEXT(locbuf);
entry->how = CENHOW(p);
free(buffer);
return (0);
}
/*
* Point to the next entry and decrement the count of valid remaining
* bytes.
*/
bytes -= entry_size;
p += entry_size;
}
free(buffer);
return (-1); /* Fell off the end the loop without a Manifest */
}
/*
* Return a new initialized jzentry corresponding to a given hash cell.
* In case of error, returns NULL.
* We already sanity-checked all the CEN headers for ZIP format errors
* in readCEN(), so we don't check them again here.
* The ZIP lock should be held here.
*/
static jzentry *
newEntry(jzfile *zip, jzcell *zc, AccessHint accessHint)
{
jlong locoff;
jint nlen, elen, clen;
jzentry *ze;
char *cen;
if ((ze = (jzentry *) malloc(sizeof(jzentry))) == NULL) return NULL;
ze->name = NULL;
ze->extra = NULL;
ze->comment = NULL;
#ifdef USE_MMAP
if (zip->usemmap) {
cen = (char*) zip->maddr + zc->cenpos - zip->offset;
} else
#endif
{
if (accessHint == ACCESS_RANDOM)
cen = readCENHeader(zip, zc->cenpos, AMPLE_CEN_HEADER_SIZE);
else
cen = sequentialAccessReadCENHeader(zip, zc->cenpos);
if (cen == NULL) goto Catch;
}
nlen = CENNAM(cen);
elen = CENEXT(cen);
clen = CENCOM(cen);
ze->time = CENTIM(cen);
ze->size = CENLEN(cen);
ze->csize = (CENHOW(cen) == STORED) ? 0 : CENSIZ(cen);
ze->crc = CENCRC(cen);
locoff = CENOFF(cen);
ze->pos = -(zip->locpos + locoff);
ze->flag = CENFLG(cen);
if ((ze->name = malloc(nlen + 1)) == NULL) goto Catch;
memcpy(ze->name, cen + CENHDR, nlen);
ze->name[nlen] = '\0';
if (elen > 0) {
char *extra = cen + CENHDR + nlen;
/* This entry has "extra" data */
if ((ze->extra = malloc(elen + 2)) == NULL) goto Catch;
ze->extra[0] = (unsigned char) elen;
ze->extra[1] = (unsigned char) (elen >> 8);
memcpy(ze->extra+2, extra, elen);
if (ze->csize == ZIP64_MAGICVAL || ze->size == ZIP64_MAGICVAL ||
locoff == ZIP64_MAGICVAL) {
jint off = 0;
while ((off + 4) < elen) { // spec: HeaderID+DataSize+Data
jint sz = SH(extra, off + 2);
if (SH(extra, off) == ZIP64_EXTID) {
off += 4;
if (ze->size == ZIP64_MAGICVAL) {
// if invalid zip64 extra fields, just skip
if (sz < 8 || (off + 8) > elen)
break;
ze->size = LL(extra, off);
sz -= 8;
off += 8;
}
if (ze->csize == ZIP64_MAGICVAL) {
if (sz < 8 || (off + 8) > elen)
break;
ze->csize = LL(extra, off);
sz -= 8;
off += 8;
}
if (locoff == ZIP64_MAGICVAL) {
if (sz < 8 || (off + 8) > elen)
break;
ze->pos = -(zip->locpos + LL(extra, off));
sz -= 8;
off += 8;
}
break;
}
off += (sz + 4);
}
}
}
/*
* Locate the manifest file with the zip/jar file.
*
* fd: File descriptor of the jar file.
* entry: To be populated with the information necessary to perform
* the inflation (the compressed and uncompressed sizes and
* the offset in the file where the compressed data is located).
*
* Returns zero upon success. Returns a negative value upon failure.
*
* The buffer for reading the Central Directory if the zip/jar file needs
* to be large enough to accommodate the largest possible single record
* and the signature of the next record which is:
*
* 3*2**16 + CENHDR + SIGSIZ
*
* Each of the three variable sized fields (name, comment and extension)
* has a maximum possible size of 64k.
*
* Typically, only a small bit of this buffer is used with bytes shuffled
* down to the beginning of the buffer. It is one thing to allocate such
* a large buffer and another thing to actually start faulting it in.
*
* In most cases, all that needs to be read are the first two entries in
* a typical jar file (META-INF and META-INF/MANIFEST.MF). Keep this factoid
* in mind when optimizing this code.
*/
static int
find_file(int fd, zentry *entry, const char *file_name)
{
int bytes;
int res;
int entry_size;
int read_size;
jlong base_offset;
Byte *p;
Byte *bp;
Byte *buffer;
Byte locbuf[LOCHDR];
if ((buffer = (Byte*)malloc(BUFSIZE)) == NULL) {
return(-1);
}
bp = buffer;
base_offset = compute_cen(fd, bp);
if (base_offset == -1) {
free(buffer);
return -1;
}
if ((bytes = read(fd, bp, MINREAD)) < 0) {
free(buffer);
return (-1);
}
p = bp;
/*
* Loop through the Central Directory Headers. Note that a valid zip/jar
* must have an ENDHDR (with ENDSIG) after the Central Directory.
*/
while (GETSIG(p) == CENSIG) {
/*
* If a complete header isn't in the buffer, shift the contents
* of the buffer down and refill the buffer. Note that the check
* for "bytes < CENHDR" must be made before the test for the entire
* size of the header, because if bytes is less than CENHDR, the
* actual size of the header can't be determined. The addition of
* SIGSIZ guarantees that the next signature is also in the buffer
* for proper loop termination.
*/
if (bytes < CENHDR) {
p = memmove(bp, p, bytes);
if ((res = read(fd, bp + bytes, MINREAD)) <= 0) {
free(buffer);
return (-1);
}
bytes += res;
}
entry_size = CENHDR + CENNAM(p) + CENEXT(p) + CENCOM(p);
if (bytes < entry_size + SIGSIZ) {
if (p != bp)
p = memmove(bp, p, bytes);
read_size = entry_size - bytes + SIGSIZ;
read_size = (read_size < MINREAD) ? MINREAD : read_size;
if ((res = read(fd, bp + bytes, read_size)) <= 0) {
free(buffer);
return (-1);
}
bytes += res;
}
/*
* Check if the name is the droid we are looking for; the jar file
* manifest. If so, build the entry record from the data found in
* the header located and return success.
*/
if ((size_t)CENNAM(p) == JLI_StrLen(file_name) &&
memcmp((p + CENHDR), file_name, JLI_StrLen(file_name)) == 0) {
if (JLI_Lseek(fd, base_offset + CENOFF(p), SEEK_SET) < (jlong)0) {
free(buffer);
return (-1);
}
if (read(fd, locbuf, LOCHDR) < 0) {
free(buffer);
return (-1);
}
if (GETSIG(locbuf) != LOCSIG) {
free(buffer);
return (-1);
}
entry->isize = CENLEN(p);
entry->csize = CENSIZ(p);
entry->offset = base_offset + CENOFF(p) + LOCHDR +
LOCNAM(locbuf) + LOCEXT(locbuf);
entry->how = CENHOW(p);
free(buffer);
return (0);
}
/*
* Point to the next entry and decrement the count of valid remaining
* bytes.
*/
bytes -= entry_size;
p += entry_size;
}
free(buffer);
return (-1); /* Fell off the end the loop without a Manifest */
}
