forked from osmocom/wireshark
![Guy Harris](/assets/img/avatar_default.png)
ZLIB_CONST must be defined before including zlib.h to expose z_const, *AND* z_const shouldn't be used unless it's defined, because older versions of zlib don't define it even if you define ZLIB_CONST. While we're at it, throw in some DIAG_OFF(cast-qual)/DIAG_ON(cast-qual) pairs to suppress unavoidable "cast throws away const qualification" warnings. The original "make zlib constness-aware" change also removed an unnecessary include of <zlib.h> from wiretap/wtap.c, so we do that as well. Change-Id: I3c5269a8fbc54bbbb4d316544cc7b8fa30614c19 Reviewed-on: https://code.wireshark.org/review/12675 Petri-Dish: Guy Harris <guy@alum.mit.edu> Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org> Reviewed-by: Guy Harris <guy@alum.mit.edu>
357 lines
8 KiB
C
357 lines
8 KiB
C
/* tvbuff_zlib.c
|
|
*
|
|
* Copyright (c) 2000 by Gilbert Ramirez <gram@alumni.rice.edu>
|
|
*
|
|
* Wireshark - Network traffic analyzer
|
|
* By Gerald Combs <gerald@wireshark.org>
|
|
* Copyright 1998 Gerald Combs
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version 2
|
|
* of the License, or (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
*/
|
|
|
|
#include "config.h"
|
|
|
|
#include <glib.h>
|
|
|
|
#include <string.h>
|
|
|
|
#ifdef HAVE_LIBZ
|
|
#define ZLIB_CONST
|
|
#include <zlib.h>
|
|
#endif
|
|
|
|
#include "tvbuff.h"
|
|
|
|
#ifdef HAVE_LIBZ
|
|
/*
|
|
* Uncompresses a zlib compressed packet inside a message of tvb at offset with
|
|
* length comprlen. Returns an uncompressed tvbuffer if uncompression
|
|
* succeeded or NULL if uncompression failed.
|
|
*/
|
|
#define TVB_Z_MIN_BUFSIZ 32768
|
|
#define TVB_Z_MAX_BUFSIZ 1048576 * 10
|
|
/* #define TVB_Z_DEBUG 1 */
|
|
#undef TVB_Z_DEBUG
|
|
|
|
tvbuff_t *
|
|
tvb_uncompress(tvbuff_t *tvb, const int offset, int comprlen)
|
|
{
|
|
gint err;
|
|
guint bytes_out = 0;
|
|
guint8 *compr;
|
|
guint8 *uncompr = NULL;
|
|
tvbuff_t *uncompr_tvb = NULL;
|
|
z_streamp strm;
|
|
Bytef *strmbuf;
|
|
guint inits_done = 0;
|
|
gint wbits = MAX_WBITS;
|
|
guint8 *next;
|
|
guint bufsiz;
|
|
#ifdef TVB_Z_DEBUG
|
|
guint inflate_passes = 0;
|
|
guint bytes_in = tvb_captured_length_remaining(tvb, offset);
|
|
#endif
|
|
|
|
if (tvb == NULL) {
|
|
return NULL;
|
|
}
|
|
|
|
compr = (guint8 *)tvb_memdup(NULL, tvb, offset, comprlen);
|
|
|
|
if (!compr)
|
|
return NULL;
|
|
|
|
/*
|
|
* Assume that the uncompressed data is at least twice as big as
|
|
* the compressed size.
|
|
*/
|
|
bufsiz = tvb_captured_length_remaining(tvb, offset) * 2;
|
|
bufsiz = CLAMP(bufsiz, TVB_Z_MIN_BUFSIZ, TVB_Z_MAX_BUFSIZ);
|
|
|
|
#ifdef TVB_Z_DEBUG
|
|
printf("bufsiz: %u bytes\n", bufsiz);
|
|
#endif
|
|
|
|
next = compr;
|
|
|
|
strm = g_new0(z_stream, 1);
|
|
strm->next_in = next;
|
|
strm->avail_in = comprlen;
|
|
|
|
strmbuf = (Bytef *)g_malloc0(bufsiz);
|
|
strm->next_out = strmbuf;
|
|
strm->avail_out = bufsiz;
|
|
|
|
err = inflateInit2(strm, wbits);
|
|
inits_done = 1;
|
|
if (err != Z_OK) {
|
|
inflateEnd(strm);
|
|
g_free(strm);
|
|
g_free(compr);
|
|
g_free(strmbuf);
|
|
return NULL;
|
|
}
|
|
|
|
while (1) {
|
|
memset(strmbuf, '\0', bufsiz);
|
|
strm->next_out = strmbuf;
|
|
strm->avail_out = bufsiz;
|
|
|
|
err = inflate(strm, Z_SYNC_FLUSH);
|
|
|
|
if (err == Z_OK || err == Z_STREAM_END) {
|
|
guint bytes_pass = bufsiz - strm->avail_out;
|
|
|
|
#ifdef TVB_Z_DEBUG
|
|
++inflate_passes;
|
|
#endif
|
|
|
|
if (uncompr == NULL) {
|
|
/*
|
|
* This is ugly workaround for bug #6480
|
|
* (https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=6480)
|
|
*
|
|
* g_memdup(..., 0) returns NULL (g_malloc(0) also)
|
|
* when uncompr is NULL logic below doesn't create tvb
|
|
* which is later interpreted as decompression failed.
|
|
*/
|
|
uncompr = (guint8 *)((bytes_pass || err != Z_STREAM_END) ?
|
|
g_memdup(strmbuf, bytes_pass) :
|
|
g_strdup(""));
|
|
} else {
|
|
guint8 *new_data = (guint8 *)g_malloc0(bytes_out + bytes_pass);
|
|
|
|
memcpy(new_data, uncompr, bytes_out);
|
|
memcpy(new_data + bytes_out, strmbuf, bytes_pass);
|
|
|
|
g_free(uncompr);
|
|
uncompr = new_data;
|
|
}
|
|
|
|
bytes_out += bytes_pass;
|
|
|
|
if (err == Z_STREAM_END) {
|
|
inflateEnd(strm);
|
|
g_free(strm);
|
|
g_free(strmbuf);
|
|
break;
|
|
}
|
|
} else if (err == Z_BUF_ERROR) {
|
|
/*
|
|
* It's possible that not enough frames were captured
|
|
* to decompress this fully, so return what we've done
|
|
* so far, if any.
|
|
*/
|
|
inflateEnd(strm);
|
|
g_free(strm);
|
|
g_free(strmbuf);
|
|
|
|
if (uncompr != NULL) {
|
|
break;
|
|
} else {
|
|
g_free(compr);
|
|
return NULL;
|
|
}
|
|
|
|
} else if (err == Z_DATA_ERROR && inits_done == 1
|
|
&& uncompr == NULL && comprlen >= 2 &&
|
|
(*compr == 0x1f) && (*(compr + 1) == 0x8b)) {
|
|
/*
|
|
* inflate() is supposed to handle both gzip and deflate
|
|
* streams automatically, but in reality it doesn't
|
|
* seem to handle either (at least not within the
|
|
* context of an HTTP response.) We have to try
|
|
* several tweaks, depending on the type of data and
|
|
* version of the library installed.
|
|
*/
|
|
|
|
/*
|
|
* Gzip file format. Skip past the header, since the
|
|
* fix to make it work (setting windowBits to 31)
|
|
* doesn't work with all versions of the library.
|
|
*/
|
|
Bytef *c = compr + 2;
|
|
Bytef flags = 0;
|
|
|
|
/* we read two bytes already (0x1f, 0x8b) and
|
|
need at least Z_DEFLATED, 1 byte flags, 4
|
|
bytes MTIME, 1 byte XFL, 1 byte OS */
|
|
if (comprlen < 10 || *c != Z_DEFLATED) {
|
|
inflateEnd(strm);
|
|
g_free(strm);
|
|
g_free(compr);
|
|
g_free(strmbuf);
|
|
return NULL;
|
|
}
|
|
|
|
c++;
|
|
flags = *c;
|
|
c++;
|
|
|
|
/* Skip past the MTIME (4 bytes),
|
|
XFL, and OS fields (1 byte each). */
|
|
c += 6;
|
|
|
|
if (flags & (1 << 2)) {
|
|
/* An Extra field is present. It
|
|
consists of 2 bytes xsize and xsize
|
|
bytes of data.
|
|
Read byte-by-byte (least significant
|
|
byte first) to make sure we abort
|
|
cleanly when the xsize is truncated
|
|
after the first byte. */
|
|
guint16 xsize = 0;
|
|
|
|
if (c-compr < comprlen) {
|
|
xsize += *c;
|
|
c++;
|
|
}
|
|
if (c-compr < comprlen) {
|
|
xsize += *c << 8;
|
|
c++;
|
|
}
|
|
|
|
c += xsize;
|
|
}
|
|
|
|
if (flags & (1 << 3)) {
|
|
/* A null terminated filename */
|
|
|
|
while ((c - compr) < comprlen && *c != '\0') {
|
|
c++;
|
|
}
|
|
|
|
c++;
|
|
}
|
|
|
|
if (flags & (1 << 4)) {
|
|
/* A null terminated comment */
|
|
|
|
while ((c - compr) < comprlen && *c != '\0') {
|
|
c++;
|
|
}
|
|
|
|
c++;
|
|
}
|
|
|
|
|
|
if (c - compr > comprlen) {
|
|
inflateEnd(strm);
|
|
g_free(strm);
|
|
g_free(compr);
|
|
g_free(strmbuf);
|
|
return NULL;
|
|
}
|
|
/* Drop gzip header */
|
|
comprlen -= (int) (c - compr);
|
|
next = c;
|
|
|
|
inflateReset(strm);
|
|
strm->next_in = next;
|
|
strm->avail_in = comprlen;
|
|
|
|
inflateEnd(strm);
|
|
inflateInit2(strm, wbits);
|
|
inits_done++;
|
|
} else if (err == Z_DATA_ERROR && uncompr == NULL &&
|
|
inits_done <= 3) {
|
|
|
|
/*
|
|
* Re-init the stream with a negative
|
|
* MAX_WBITS. This is necessary due to
|
|
* some servers (Apache) not sending
|
|
* the deflate header with the
|
|
* content-encoded response.
|
|
*/
|
|
wbits = -MAX_WBITS;
|
|
|
|
inflateReset(strm);
|
|
|
|
strm->next_in = next;
|
|
strm->avail_in = comprlen;
|
|
|
|
inflateEnd(strm);
|
|
memset(strmbuf, '\0', bufsiz);
|
|
strm->next_out = strmbuf;
|
|
strm->avail_out = bufsiz;
|
|
|
|
err = inflateInit2(strm, wbits);
|
|
|
|
inits_done++;
|
|
|
|
if (err != Z_OK) {
|
|
g_free(strm);
|
|
g_free(strmbuf);
|
|
g_free(compr);
|
|
g_free(uncompr);
|
|
|
|
return NULL;
|
|
}
|
|
} else {
|
|
inflateEnd(strm);
|
|
g_free(strm);
|
|
g_free(strmbuf);
|
|
|
|
if (uncompr == NULL) {
|
|
g_free(compr);
|
|
return NULL;
|
|
}
|
|
|
|
break;
|
|
}
|
|
}
|
|
|
|
#ifdef TVB_Z_DEBUG
|
|
printf("inflate() total passes: %u\n", inflate_passes);
|
|
printf("bytes in: %u\nbytes out: %u\n\n", bytes_in, bytes_out);
|
|
#endif
|
|
|
|
if (uncompr != NULL) {
|
|
uncompr_tvb = tvb_new_real_data((guint8*) uncompr, bytes_out, bytes_out);
|
|
tvb_set_free_cb(uncompr_tvb, g_free);
|
|
}
|
|
g_free(compr);
|
|
return uncompr_tvb;
|
|
}
|
|
#else
|
|
tvbuff_t *
|
|
tvb_uncompress(tvbuff_t *tvb _U_, const int offset _U_, int comprlen _U_)
|
|
{
|
|
return NULL;
|
|
}
|
|
#endif
|
|
|
|
tvbuff_t *
|
|
tvb_child_uncompress(tvbuff_t *parent, tvbuff_t *tvb, const int offset, int comprlen)
|
|
{
|
|
tvbuff_t *new_tvb = tvb_uncompress(tvb, offset, comprlen);
|
|
if (new_tvb)
|
|
tvb_set_child_real_data_tvbuff (parent, new_tvb);
|
|
return new_tvb;
|
|
}
|
|
|
|
/*
|
|
* Editor modelines - http://www.wireshark.org/tools/modelines.html
|
|
*
|
|
* Local variables:
|
|
* c-basic-offset: 8
|
|
* tab-width: 8
|
|
* indent-tabs-mode: t
|
|
* End:
|
|
*
|
|
* vi: set shiftwidth=8 tabstop=8 noexpandtab:
|
|
* :indentSize=8:tabSize=8:noTabs=false:
|
|
*/
|