freebsd-dev/lib/libarchive/archive_read_support_compression_gzip.c
Tim Kientzle a612d4d7ae Don't try to read the next Gzip header after we reach the
end of the compressed stream.  This is desirable behavior,
but the implementation here is very broken and causes strange
problems, so disable it for now.

Thanks to Simon L. Nielsen for reporting this problem.
2009-01-01 02:29:57 +00:00

492 lines
13 KiB
C

/*-
* Copyright (c) 2003-2007 Tim Kientzle
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "archive_platform.h"
__FBSDID("$FreeBSD$");
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_ZLIB_H
#include <zlib.h>
#endif
#include "archive.h"
#include "archive_private.h"
#include "archive_read_private.h"
#ifdef HAVE_ZLIB_H
struct private_data {
z_stream stream;
unsigned char *out_block;
size_t out_block_size;
int64_t total_out;
unsigned long crc;
int header_count;
char header_done;
char header_state;
char header_flags;
char eof; /* True = found end of compressed data. */
};
/* Gzip Source. */
static ssize_t gzip_source_read(struct archive_read_source *, const void **);
static int gzip_source_close(struct archive_read_source *);
#endif
/*
* Note that we can detect gzip archives even if we can't decompress
* them. (In fact, we like detecting them because we can give better
* error messages.) So the bid framework here gets compiled even
* if zlib is unavailable.
*/
static int gzip_reader_bid(struct archive_reader *, const void *, size_t);
static struct archive_read_source *gzip_reader_init(struct archive_read *,
struct archive_reader *, struct archive_read_source *,
const void *, size_t);
static int gzip_reader_free(struct archive_reader *);
int
archive_read_support_compression_gzip(struct archive *_a)
{
struct archive_read *a = (struct archive_read *)_a;
struct archive_reader *reader = __archive_read_get_reader(a);
if (reader == NULL)
return (ARCHIVE_FATAL);
reader->data = NULL;
reader->bid = gzip_reader_bid;
reader->init = gzip_reader_init;
reader->free = gzip_reader_free;
return (ARCHIVE_OK);
}
static int
gzip_reader_free(struct archive_reader *self){
(void)self; /* UNUSED */
return (ARCHIVE_OK);
}
/*
* Test whether we can handle this data.
*
* This logic returns zero if any part of the signature fails. It
* also tries to Do The Right Thing if a very short buffer prevents us
* from verifying as much as we would like.
*/
static int
gzip_reader_bid(struct archive_reader *self, const void *buff, size_t len)
{
const unsigned char *buffer;
int bits_checked;
(void)self; /* UNUSED */
if (len < 1)
return (0);
buffer = (const unsigned char *)buff;
bits_checked = 0;
if (buffer[0] != 037) /* Verify first ID byte. */
return (0);
bits_checked += 8;
if (len < 2)
return (bits_checked);
if (buffer[1] != 0213) /* Verify second ID byte. */
return (0);
bits_checked += 8;
if (len < 3)
return (bits_checked);
if (buffer[2] != 8) /* Compression must be 'deflate'. */
return (0);
bits_checked += 8;
if (len < 4)
return (bits_checked);
if ((buffer[3] & 0xE0)!= 0) /* No reserved flags set. */
return (0);
bits_checked += 3;
if (len < 5)
return (bits_checked);
/*
* TODO: Verify more; in particular, gzip has an optional
* header CRC, which would give us 16 more verified bits. We
* may also be able to verify certain constraints on other
* fields.
*/
return (bits_checked);
}
#ifndef HAVE_ZLIB_H
/*
* If we don't have the library on this system, we can't actually do the
* decompression. We can, however, still detect compressed archives
* and emit a useful message.
*/
static struct archive_read_source *
gzip_reader_init(struct archive_read *a, struct archive_reader *reader,
struct archive_read_source *upstream, const void *buff, size_t n)
{
(void)a; /* UNUSED */
(void)buff; /* UNUSED */
(void)n; /* UNUSED */
archive_set_error(&a->archive, -1,
"This version of libarchive was compiled without gzip support");
return (NULL);
}
#else
/*
* Initialize the source object.
*/
static struct archive_read_source *
gzip_reader_init(struct archive_read *a, struct archive_reader *reader,
struct archive_read_source *upstream, const void *buff, size_t n)
{
static const size_t out_block_size = 64 * 1024;
void *out_block;
struct archive_read_source *self;
struct private_data *state;
(void)reader; /* UNUSED */
a->archive.compression_code = ARCHIVE_COMPRESSION_GZIP;
a->archive.compression_name = "gzip";
self = calloc(sizeof(*self), 1);
state = (struct private_data *)calloc(sizeof(*state), 1);
out_block = (unsigned char *)malloc(out_block_size);
if (self == NULL || state == NULL || out_block == NULL) {
archive_set_error(&a->archive, ENOMEM,
"Can't allocate data for %s decompression",
a->archive.compression_name);
free(out_block);
free(state);
free(self);
return (NULL);
}
self->archive = a;
self->data = state;
state->out_block_size = out_block_size;
state->out_block = out_block;
self->upstream = upstream;
self->read = gzip_source_read;
self->skip = NULL; /* not supported */
self->close = gzip_source_close;
state->crc = crc32(0L, NULL, 0);
state->header_done = 0; /* We've not yet begun to parse header... */
/*
* A bug in zlib.h: stream.next_in should be marked 'const'
* but isn't (the library never alters data through the
* next_in pointer, only reads it). The result: this ugly
* cast to remove 'const'.
*/
state->stream.next_in = (Bytef *)(uintptr_t)(const void *)buff;
state->stream.avail_in = n;
return (self);
}
static int
header(struct archive_read_source *self)
{
struct private_data *state;
int ret, b;
state = (struct private_data *)self->data;
/*
* If still parsing the header, interpret the
* next byte.
*/
b = *(state->stream.next_in++);
state->stream.avail_in--;
/*
* Simple state machine to parse the GZip header one byte at
* a time. If you see a way to make this easier to understand,
* please let me know. ;-)
*/
switch (state->header_state) {
case 0: /* First byte of signature. */
/* We only return EOF for a failure here. */
if (b != 037)
return (ARCHIVE_EOF);
state->header_state = 1;
break;
case 1: /* Second byte of signature. */
case 2: /* Compression type must be 8 == deflate. */
if (b != (0xff & "\037\213\010"[(int)state->header_state])) {
archive_set_error(&self->archive->archive,
ARCHIVE_ERRNO_MISC,
"Invalid GZip header (saw %d at offset %d)",
b, state->header_state);
return (ARCHIVE_FATAL);
}
++state->header_state;
break;
case 3: /* GZip flags. */
state->header_flags = b;
state->header_state = 4;
break;
case 4: case 5: case 6: case 7: /* Mod time. */
case 8: /* Deflate flags. */
case 9: /* OS. */
++state->header_state;
break;
case 10: /* Optional Extra: First byte of Length. */
if ((state->header_flags & 4)) {
state->header_count = 255 & (int)b;
state->header_state = 11;
break;
}
/* Fall through if no Optional Extra field. */
case 11: /* Optional Extra: Second byte of Length. */
if ((state->header_flags & 4)) {
state->header_count
= (0xff00 & ((int)b << 8)) | state->header_count;
state->header_state = 12;
break;
}
/* Fall through if no Optional Extra field. */
case 12: /* Optional Extra Field: counted length. */
if ((state->header_flags & 4)) {
--state->header_count;
if (state->header_count == 0) state->header_state = 13;
else state->header_state = 12;
break;
}
/* Fall through if no Optional Extra field. */
case 13: /* Optional Original Filename. */
if ((state->header_flags & 8)) {
if (b == 0) state->header_state = 14;
else state->header_state = 13;
break;
}
/* Fall through if no Optional Original Filename. */
case 14: /* Optional Comment. */
if ((state->header_flags & 16)) {
if (b == 0) state->header_state = 15;
else state->header_state = 14;
break;
}
/* Fall through if no Optional Comment. */
case 15: /* Optional Header CRC: First byte. */
if ((state->header_flags & 2)) {
state->header_state = 16;
break;
}
/* Fall through if no Optional Header CRC. */
case 16: /* Optional Header CRC: Second byte. */
if ((state->header_flags & 2)) {
state->header_state = 17;
break;
}
/* Fall through if no Optional Header CRC. */
case 17: /* First byte of compressed data. */
state->header_done = 1; /* done with header */
state->stream.avail_in++; /* Discard first byte. */
state->stream.next_in--;
/* Initialize compression library. */
ret = inflateInit2(&(state->stream),
-15 /* Don't check for zlib header */);
/* Decipher the error code. */
switch (ret) {
case Z_OK:
return (ARCHIVE_OK);
case Z_STREAM_ERROR:
archive_set_error(&self->archive->archive,
ARCHIVE_ERRNO_MISC,
"Internal error initializing compression library: "
"invalid setup parameter");
break;
case Z_MEM_ERROR:
archive_set_error(&self->archive->archive, ENOMEM,
"Internal error initializing compression library: "
"out of memory");
break;
case Z_VERSION_ERROR:
archive_set_error(&self->archive->archive,
ARCHIVE_ERRNO_MISC,
"Internal error initializing compression library: "
"invalid library version");
break;
default:
archive_set_error(&self->archive->archive,
ARCHIVE_ERRNO_MISC,
"Internal error initializing compression library: "
" Zlib error %d", ret);
break;
}
return (ARCHIVE_FATAL);
}
return (ARCHIVE_OK);
}
static ssize_t
gzip_source_read(struct archive_read_source *self, const void **p)
{
struct private_data *state;
size_t read_avail, decompressed;
const void *read_buf;
int ret;
state = (struct private_data *)self->data;
read_avail = 0;
/* Empty our output buffer. */
state->stream.next_out = state->out_block;
state->stream.avail_out = state->out_block_size;
/* Try to fill the output buffer. */
while (state->stream.avail_out > 0 && !state->eof) {
/* If the last upstream block is done, get another one. */
if (state->stream.avail_in == 0) {
ret = (self->upstream->read)(self->upstream,
&read_buf);
/* stream.next_in is really const, but zlib
* doesn't declare it so. <sigh> */
state->stream.next_in
= (unsigned char *)(uintptr_t)read_buf;
if (ret < 0)
return (ARCHIVE_FATAL);
state->stream.avail_in = ret;
/* There is no more data, return whatever we have. */
if (ret == 0) {
state->eof = 1;
break;
}
}
/* If we're still parsing header bytes, walk through those. */
if (!state->header_done) {
ret = header(self);
if (ret < ARCHIVE_OK)
return (ret);
if (ret == ARCHIVE_EOF)
state->eof = 1;
} else {
/* Decompress as much as we can in one pass. */
/* XXX Skip trailer XXX */
ret = inflate(&(state->stream), 0);
switch (ret) {
case Z_STREAM_END: /* Found end of stream. */
switch (inflateEnd(&(state->stream))) {
case Z_OK:
break;
default:
archive_set_error(&self->archive->archive,
ARCHIVE_ERRNO_MISC,
"Failed to clean up gzip decompressor");
return (ARCHIVE_FATAL);
}
/* zlib has been torn down */
state->header_done = 0;
state->eof = 1;
/* FALL THROUGH */
case Z_OK: /* Decompressor made some progress. */
/* If we filled our buffer, update stats and return. */
break;
default:
/* Return an error. */
archive_set_error(&self->archive->archive,
ARCHIVE_ERRNO_MISC,
"%s decompression failed",
self->archive->archive.compression_name);
return (ARCHIVE_FATAL);
}
}
}
/* We've read as much as we can. */
decompressed = state->stream.next_out - state->out_block;
state->total_out += decompressed;
if (decompressed == 0)
*p = NULL;
else
*p = state->out_block;
return (decompressed);
}
/*
* Clean up the decompressor.
*/
static int
gzip_source_close(struct archive_read_source *self)
{
struct private_data *state;
int ret;
state = (struct private_data *)self->data;
ret = ARCHIVE_OK;
if (state->header_done) {
switch (inflateEnd(&(state->stream))) {
case Z_OK:
break;
default:
archive_set_error(&(self->archive->archive),
ARCHIVE_ERRNO_MISC,
"Failed to clean up %s compressor",
self->archive->archive.compression_name);
ret = ARCHIVE_FATAL;
}
}
free(state->out_block);
free(state);
free(self);
return (ret);
}
#endif /* HAVE_ZLIB_H */