nexmon – Rev 1
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/* file-png.c
*
* Routines for PNG (Portable Network Graphics) image file dissection
*
* Copyright 2006 Ronnie Sahlberg
*
* 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.
*/
/* See http://www.w3.org/TR/PNG for specification
*/
#define NEW_PROTO_TREE_API
#include "config.h"
#include <epan/packet.h>
#include <epan/expert.h>
#define MAKE_TYPE_VAL(a, b, c, d) ((a)<<24 | (b)<<16 | (c)<<8 | (d))
#define CHUNK_TYPE_IHDR MAKE_TYPE_VAL('I', 'H', 'D', 'R')
#define CHUNK_TYPE_bKGD MAKE_TYPE_VAL('b', 'K', 'G', 'D')
#define CHUNK_TYPE_gAMA MAKE_TYPE_VAL('g', 'A', 'M', 'A')
#define CHUNK_TYPE_iCCP MAKE_TYPE_VAL('i', 'C', 'C', 'P')
#define CHUNK_TYPE_cHRM MAKE_TYPE_VAL('c', 'H', 'R', 'M')
#define CHUNK_TYPE_pHYs MAKE_TYPE_VAL('p', 'H', 'Y', 's')
#define CHUNK_TYPE_iTXt MAKE_TYPE_VAL('i', 'T', 'X', 't')
#define CHUNK_TYPE_tEXt MAKE_TYPE_VAL('t', 'E', 'X', 't')
#define CHUNK_TYPE_sBIT MAKE_TYPE_VAL('s', 'B', 'I', 'T')
#define CHUNK_TYPE_sRGB MAKE_TYPE_VAL('s', 'R', 'G', 'B')
#define CHUNK_TYPE_tIME MAKE_TYPE_VAL('t', 'I', 'M', 'E')
#define CHUNK_TYPE_IDAT MAKE_TYPE_VAL('I', 'D', 'A', 'T')
#define CHUNK_TYPE_IEND MAKE_TYPE_VAL('I', 'E', 'N', 'D')
#define CHUNK_TYPE_tRNS MAKE_TYPE_VAL('t', 'R', 'N', 'S')
#define CHUNK_TYPE_PLTE MAKE_TYPE_VAL('P', 'L', 'T', 'E')
static const value_string chunk_types[] = {
{ CHUNK_TYPE_IHDR, "Image Header" },
{ CHUNK_TYPE_bKGD, "Background colour" },
{ CHUNK_TYPE_gAMA, "Image gamma" },
{ CHUNK_TYPE_iCCP, "Embedded ICC profile" },
{ CHUNK_TYPE_cHRM, "Primary chromaticities and white point" },
{ CHUNK_TYPE_pHYs, "Physical pixel dimensions" },
{ CHUNK_TYPE_iTXt, "International textual data" },
{ CHUNK_TYPE_tEXt, "Textual data" },
{ CHUNK_TYPE_sBIT, "Significant bits" },
{ CHUNK_TYPE_sRGB, "Standard RGB colour space" },
{ CHUNK_TYPE_tIME, "Image last-modification time" },
{ CHUNK_TYPE_IDAT, "Image data chunk" },
{ CHUNK_TYPE_IEND, "Image Trailer" },
{ CHUNK_TYPE_tRNS, "Transparency" },
{ CHUNK_TYPE_PLTE, "Palette" },
{ 0, NULL }
};
void proto_register_png(void);
void proto_reg_handoff_png(void);
static header_field_info *hfi_png = NULL;
#define PNG_HFI_INIT HFI_INIT(proto_png)
static header_field_info hfi_png_signature PNG_HFI_INIT = {
"PNG Signature", "png.signature", FT_BYTES, BASE_NONE,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_chunk_data PNG_HFI_INIT = {
"Data", "png.chunk.data", FT_NONE, BASE_NONE,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_chunk_type_str PNG_HFI_INIT = {
"Chunk", "png.chunk.type", FT_STRING, BASE_NONE,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_chunk_len PNG_HFI_INIT = {
"Len", "png.chunk.len", FT_UINT32, BASE_DEC,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_chunk_crc PNG_HFI_INIT = {
"CRC", "png.chunk.crc", FT_UINT32, BASE_HEX,
NULL, 0, NULL, HFILL };
static const true_false_string png_chunk_anc = {
"This is an ANCILLARY chunk",
"This is a CRITICAL chunk"
};
static header_field_info hfi_png_chunk_flag_anc PNG_HFI_INIT = {
"Ancillary", "png.chunk.flag.ancillary", FT_BOOLEAN, 32,
TFS(&png_chunk_anc), 0x20000000, NULL, HFILL };
static const true_false_string png_chunk_priv = {
"This is a PRIVATE chunk",
"This is a PUBLIC chunk"
};
static header_field_info hfi_png_chunk_flag_priv PNG_HFI_INIT = {
"Private", "png.chunk.flag.private", FT_BOOLEAN, 32,
TFS(&png_chunk_priv), 0x00200000, NULL, HFILL };
static const true_false_string png_chunk_stc = {
"This chunk is SAFE TO COPY",
"This chunk is NOT safe to copy"
};
static header_field_info hfi_png_chunk_flag_stc PNG_HFI_INIT = {
"Safe To Copy", "png.chunk.flag.stc", FT_BOOLEAN, 32,
TFS(&png_chunk_stc), 0x00000020, NULL, HFILL };
static header_field_info hfi_png_ihdr_width PNG_HFI_INIT = {
"Width", "png.ihdr.width", FT_UINT32, BASE_DEC,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_ihdr_height PNG_HFI_INIT = {
"Height", "png.ihdr.height", FT_UINT32, BASE_DEC,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_ihdr_bitdepth PNG_HFI_INIT = {
"Bit Depth", "png.ihdr.bitdepth", FT_UINT8, BASE_DEC,
NULL, 0, NULL, HFILL };
static const value_string colour_type_vals[] = {
{ 0, "Greyscale"},
{ 2, "Truecolour"},
{ 3, "Indexed-colour"},
{ 4, "Greyscale with alpha"},
{ 6, "Truecolour with alpha"},
{ 0, NULL }
};
static header_field_info hfi_png_ihdr_colour_type PNG_HFI_INIT = {
"Colour Type", "png.ihdr.colour_type", FT_UINT8, BASE_DEC,
VALS(colour_type_vals), 0, NULL, HFILL };
static const value_string compression_method_vals[] = {
{ 0, "Deflate"},
{ 0, NULL }
};
static header_field_info hfi_png_ihdr_compression_method PNG_HFI_INIT = {
"Compression Method", "png.ihdr.compression_method", FT_UINT8, BASE_DEC,
VALS(compression_method_vals), 0, NULL, HFILL };
static const value_string filter_method_vals[] = {
{ 0, "Adaptive"},
{ 0, NULL }
};
static header_field_info hfi_png_ihdr_filter_method PNG_HFI_INIT = {
"Filter Method", "png.ihdr.filter_method", FT_UINT8, BASE_DEC,
VALS(filter_method_vals), 0, NULL, HFILL };
static const value_string interlace_method_vals[] = {
{ 0, "No interlace"},
{ 1, "Adam7"},
{ 0, NULL }
};
static header_field_info hfi_png_ihdr_interlace_method PNG_HFI_INIT = {
"Interlace Method", "png.ihdr.interlace_method", FT_UINT8, BASE_DEC,
VALS(interlace_method_vals), 0, NULL, HFILL };
static const value_string srgb_intent_vals[] = {
{ 0, "Perceptual" },
{ 1, "Relative colorimetric" },
{ 2, "Saturation" },
{ 3, "Absolute colorimetric" },
{ 0, NULL }
};
static header_field_info hfi_png_srgb_intent PNG_HFI_INIT = {
"Intent", "png.srgb.intent", FT_UINT8, BASE_DEC,
VALS(srgb_intent_vals), 0, NULL, HFILL };
static header_field_info hfi_png_text_keyword PNG_HFI_INIT = {
"Keyword", "png.text.keyword", FT_STRING, STR_UNICODE,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_text_string PNG_HFI_INIT = {
"String", "png.text.string", FT_STRING, STR_UNICODE,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_time_year PNG_HFI_INIT = {
"Year", "png.time.year", FT_UINT16, BASE_DEC,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_time_month PNG_HFI_INIT = {
"Month", "png.time.month", FT_UINT8, BASE_DEC,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_time_day PNG_HFI_INIT = {
"Day", "png.time.day", FT_UINT8, BASE_DEC,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_time_hour PNG_HFI_INIT = {
"Hour", "png.time.hour", FT_UINT8, BASE_DEC,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_time_minute PNG_HFI_INIT = {
"Minute", "png.time.minute", FT_UINT8, BASE_DEC,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_time_second PNG_HFI_INIT = {
"Second", "png.time.second", FT_UINT8, BASE_DEC,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_phys_horiz PNG_HFI_INIT = {
"Horizontal pixels per unit", "png.phys.horiz", FT_UINT32, BASE_DEC,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_phys_vert PNG_HFI_INIT = {
"Vertical pixels per unit", "png.phys.vert", FT_UINT32, BASE_DEC,
NULL, 0, NULL, HFILL };
static const value_string phys_unit_vals[] = {
{ 0, "Unit is unknown"},
{ 1, "Unit is METRE"},
{ 0, NULL }
};
static header_field_info hfi_png_phys_unit PNG_HFI_INIT = {
"Unit", "png.phys.unit", FT_UINT8, BASE_DEC,
VALS(phys_unit_vals), 0, NULL, HFILL };
static header_field_info hfi_png_bkgd_palette_index PNG_HFI_INIT = {
"Palette Index", "png.bkgd.palette_index", FT_UINT8, BASE_DEC,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_bkgd_greyscale PNG_HFI_INIT = {
"Greyscale", "png.bkgd.greyscale", FT_UINT16, BASE_HEX,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_bkgd_red PNG_HFI_INIT = {
"Red", "png.bkgd.red", FT_UINT16, BASE_HEX,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_bkgd_green PNG_HFI_INIT = {
"Green", "png.bkgd.green", FT_UINT16, BASE_HEX,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_bkgd_blue PNG_HFI_INIT = {
"Blue", "png.bkgd.blue", FT_UINT16, BASE_HEX,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_chrm_white_x PNG_HFI_INIT = {
"White X", "png.chrm.white.x", FT_FLOAT, BASE_NONE,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_chrm_white_y PNG_HFI_INIT = {
"White Y", "png.chrm.white.y", FT_FLOAT, BASE_NONE,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_chrm_red_x PNG_HFI_INIT = {
"Red X", "png.chrm.red.x", FT_FLOAT, BASE_NONE,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_chrm_red_y PNG_HFI_INIT = {
"Red Y", "png.chrm.red.y", FT_FLOAT, BASE_NONE,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_chrm_green_x PNG_HFI_INIT = {
"Green X", "png.chrm.green.x", FT_FLOAT, BASE_NONE,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_chrm_green_y PNG_HFI_INIT = {
"Green Y", "png.chrm.green.y", FT_FLOAT, BASE_NONE,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_chrm_blue_x PNG_HFI_INIT = {
"Blue X", "png.chrm.blue.x", FT_FLOAT, BASE_NONE,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_chrm_blue_y PNG_HFI_INIT = {
"Blue Y", "png.chrm.blue.y", FT_FLOAT, BASE_NONE,
NULL, 0, NULL, HFILL };
static header_field_info hfi_png_gama_gamma PNG_HFI_INIT = {
"Gamma", "png.gama.gamma", FT_FLOAT, BASE_NONE,
NULL, 0, NULL, HFILL };
static gint ett_png = -1;
static gint ett_png_chunk = -1;
static expert_field ei_png_chunk_too_large = EI_INIT;
static dissector_handle_t png_handle;
static void
dissect_png_ihdr(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree)
{
proto_tree_add_item(tree, &hfi_png_ihdr_width, tvb, 0, 4, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, &hfi_png_ihdr_height, tvb, 4, 4, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, &hfi_png_ihdr_bitdepth, tvb, 8, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, &hfi_png_ihdr_colour_type, tvb, 9, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, &hfi_png_ihdr_compression_method, tvb, 10, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, &hfi_png_ihdr_filter_method, tvb, 11, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, &hfi_png_ihdr_interlace_method, tvb, 12, 1, ENC_BIG_ENDIAN);
}
static void
dissect_png_srgb(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree)
{
proto_tree_add_item(tree, &hfi_png_srgb_intent,
tvb, 0, 1, ENC_BIG_ENDIAN);
}
static void
dissect_png_text(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree)
{
gint offset=0, nul_offset;
nul_offset = tvb_find_guint8(tvb, offset, tvb_captured_length_remaining(tvb, offset), 0);
/* nul_offset == 0 means empty keyword, this is not allowed by the png standard */
if (nul_offset<=0) {
/* XXX exception */
return;
}
proto_tree_add_item(tree, &hfi_png_text_keyword, tvb, offset, nul_offset, ENC_ISO_8859_1|ENC_NA);
offset = nul_offset+1; /* length of the key word + 0 character */
proto_tree_add_item(tree, &hfi_png_text_string, tvb, offset, tvb_captured_length_remaining(tvb, offset), ENC_ISO_8859_1|ENC_NA);
}
static void
dissect_png_time(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree)
{
proto_tree_add_item(tree, &hfi_png_time_year, tvb, 0, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, &hfi_png_time_month, tvb, 2, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, &hfi_png_time_day, tvb, 3, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, &hfi_png_time_hour, tvb, 4, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, &hfi_png_time_minute, tvb, 5, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, &hfi_png_time_second, tvb, 6, 1, ENC_BIG_ENDIAN);
}
static void
dissect_png_phys(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree)
{
proto_tree_add_item(tree, &hfi_png_phys_horiz, tvb, 0, 4, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, &hfi_png_phys_vert, tvb, 4, 4, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, &hfi_png_phys_unit, tvb, 8, 1, ENC_BIG_ENDIAN);
}
static void
dissect_png_bkgd(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree)
{
switch(tvb_reported_length(tvb)){
case 1: /* colour type 3 */
proto_tree_add_item(tree, &hfi_png_bkgd_palette_index, tvb, 0, 1, ENC_BIG_ENDIAN);
break;
case 2: /* colour type 0, 4 */
proto_tree_add_item(tree, &hfi_png_bkgd_greyscale, tvb, 0, 2, ENC_BIG_ENDIAN);
break;
case 6: /* colour type 2, 6 */
proto_tree_add_item(tree, &hfi_png_bkgd_red, tvb, 0, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, &hfi_png_bkgd_green, tvb, 2, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, &hfi_png_bkgd_blue, tvb, 4, 2, ENC_BIG_ENDIAN);
break;
}
}
static void
dissect_png_chrm(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree)
{
float wx, wy, rx, ry, gx, gy, bx, by;
gint offset = 0;
wx = tvb_get_ntohl(tvb, offset) / 100000.0f;
proto_tree_add_float_format_value(tree, &hfi_png_chrm_white_x,
tvb, offset, 4, wx, "%f", wx);
offset += 4;
wy = tvb_get_ntohl(tvb, offset) / 100000.0f;
proto_tree_add_float_format_value(tree, &hfi_png_chrm_white_y,
tvb, offset, 4, wy, "%f", wy);
offset += 4;
rx = tvb_get_ntohl(tvb, offset) / 100000.0f;
proto_tree_add_float_format_value(tree, &hfi_png_chrm_red_x,
tvb, offset, 4, rx, "%f", rx);
offset += 4;
ry = tvb_get_ntohl(tvb, offset) / 100000.0f;
proto_tree_add_float_format_value(tree, &hfi_png_chrm_red_y,
tvb, offset, 4, ry, "%f", ry);
offset += 4;
gx = tvb_get_ntohl(tvb, offset) / 100000.0f;
proto_tree_add_float_format_value(tree, &hfi_png_chrm_green_x,
tvb, offset, 4, gx, "%f", gx);
offset += 4;
gy = tvb_get_ntohl(tvb, offset) / 100000.0f;
proto_tree_add_float_format_value(tree, &hfi_png_chrm_green_y,
tvb, offset, 4, gy, "%f", gy);
offset += 4;
bx = tvb_get_ntohl(tvb, offset) / 100000.0f;
proto_tree_add_float_format_value(tree, &hfi_png_chrm_blue_x,
tvb, offset, 4, bx, "%f", bx);
offset += 4;
by = tvb_get_ntohl(tvb, offset) / 100000.0f;
proto_tree_add_float_format_value(tree, &hfi_png_chrm_blue_y,
tvb, offset, 4, by, "%f", by);
}
static void
dissect_png_gama(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree)
{
float gamma;
gamma = tvb_get_ntohl(tvb, 0) / 100000.0f;
proto_tree_add_float_format_value(tree, &hfi_png_gama_gamma,
tvb, 0, 4, gamma, "%f", gamma);
}
static gint
dissect_png(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, void *data _U_)
{
proto_tree *tree;
proto_item *ti;
gint offset=0;
/* http://libpng.org/pub/png/spec/1.2/PNG-Structure.html#PNG-file-signature */
static const guint8 magic[8] = { 137, 80, 78, 71, 13, 10, 26, 10 };
if (tvb_captured_length(tvb) < 20)
return 0;
if (tvb_memeql(tvb, 0, magic, sizeof(magic)) != 0)
return 0;
col_append_str(pinfo->cinfo, COL_INFO, " (PNG)");
ti=proto_tree_add_item(parent_tree, hfi_png, tvb, offset, -1, ENC_NA);
tree=proto_item_add_subtree(ti, ett_png);
proto_tree_add_item(tree, &hfi_png_signature, tvb, offset, 8, ENC_NA);
offset+=8;
while(tvb_reported_length_remaining(tvb, offset) > 0){
guint32 len_field;
proto_item *len_it;
proto_tree *chunk_tree;
guint32 type;
guint8 *type_str;
tvbuff_t *chunk_tvb;
len_field = tvb_get_ntohl(tvb, offset);
type = tvb_get_ntohl(tvb, offset+4);
type_str = tvb_get_string_enc(wmem_packet_scope(),
tvb, offset+4, 4, ENC_ASCII|ENC_NA);
/* 4 byte len field, 4 byte chunk type, 4 byte CRC */
chunk_tree = proto_tree_add_subtree_format(tree, tvb, offset, 4+4+len_field+4, ett_png_chunk, NULL,
"%s (%s)", val_to_str_const(type, chunk_types, "unknown"), type_str);
len_it = proto_tree_add_item(chunk_tree, &hfi_png_chunk_len,
tvb, offset, 4, ENC_BIG_ENDIAN);
offset+=4;
if (len_field > G_MAXINT) {
expert_add_info(pinfo, len_it, &ei_png_chunk_too_large);
return offset;
}
proto_tree_add_item(chunk_tree, &hfi_png_chunk_type_str,
tvb, offset, 4, ENC_ASCII|ENC_NA);
proto_tree_add_item(chunk_tree, &hfi_png_chunk_flag_anc, tvb, offset, 4, ENC_BIG_ENDIAN);
proto_tree_add_item(chunk_tree, &hfi_png_chunk_flag_priv, tvb, offset, 4, ENC_BIG_ENDIAN);
proto_tree_add_item(chunk_tree, &hfi_png_chunk_flag_stc, tvb, offset, 4, ENC_BIG_ENDIAN);
offset+=4;
chunk_tvb=tvb_new_subset_length(tvb, offset, len_field);
switch (type) {
case CHUNK_TYPE_IHDR:
dissect_png_ihdr(chunk_tvb, pinfo, chunk_tree);
break;
case CHUNK_TYPE_bKGD:
dissect_png_bkgd(chunk_tvb, pinfo, chunk_tree);
break;
case CHUNK_TYPE_cHRM:
dissect_png_chrm(chunk_tvb, pinfo, chunk_tree);
break;
case CHUNK_TYPE_gAMA:
dissect_png_gama(chunk_tvb, pinfo, chunk_tree);
break;
case CHUNK_TYPE_pHYs:
dissect_png_phys(chunk_tvb, pinfo, chunk_tree);
break;
case CHUNK_TYPE_sRGB:
dissect_png_srgb(chunk_tvb, pinfo, chunk_tree);
break;
case CHUNK_TYPE_tEXt:
dissect_png_text(chunk_tvb, pinfo, chunk_tree);
break;
case CHUNK_TYPE_tIME:
dissect_png_time(chunk_tvb, pinfo, chunk_tree);
break;
default:
if (len_field>0) {
proto_tree_add_item(chunk_tree, &hfi_png_chunk_data,
tvb, offset, len_field, ENC_NA);
}
break;
}
offset += len_field;
proto_tree_add_item(chunk_tree, &hfi_png_chunk_crc, tvb, offset, 4, ENC_BIG_ENDIAN);
offset+=4;
}
return offset;
}
void
proto_register_png(void)
{
#ifndef HAVE_HFI_SECTION_INIT
static header_field_info *hfi[] =
{
&hfi_png_signature,
&hfi_png_chunk_type_str,
&hfi_png_chunk_data,
&hfi_png_chunk_len,
&hfi_png_chunk_crc,
&hfi_png_chunk_flag_anc,
&hfi_png_chunk_flag_priv,
&hfi_png_chunk_flag_stc,
&hfi_png_ihdr_width,
&hfi_png_ihdr_height,
&hfi_png_ihdr_bitdepth,
&hfi_png_ihdr_colour_type,
&hfi_png_ihdr_compression_method,
&hfi_png_ihdr_filter_method,
&hfi_png_ihdr_interlace_method,
&hfi_png_srgb_intent,
&hfi_png_text_keyword,
&hfi_png_text_string,
&hfi_png_time_year,
&hfi_png_time_month,
&hfi_png_time_day,
&hfi_png_time_hour,
&hfi_png_time_minute,
&hfi_png_time_second,
&hfi_png_phys_horiz,
&hfi_png_phys_vert,
&hfi_png_phys_unit,
&hfi_png_bkgd_palette_index,
&hfi_png_bkgd_greyscale,
&hfi_png_bkgd_red,
&hfi_png_bkgd_green,
&hfi_png_bkgd_blue,
&hfi_png_chrm_white_x,
&hfi_png_chrm_white_y,
&hfi_png_chrm_red_x,
&hfi_png_chrm_red_y,
&hfi_png_chrm_green_x,
&hfi_png_chrm_green_y,
&hfi_png_chrm_blue_x,
&hfi_png_chrm_blue_y,
&hfi_png_gama_gamma
};
#endif
static gint *ett[] =
{
&ett_png,
&ett_png_chunk,
};
static ei_register_info ei[] = {
{ &ei_png_chunk_too_large,
{ "png.chunk_too_large", PI_PROTOCOL, PI_WARN,
"chunk size too large, dissection of this chunk is not supported", EXPFILL }}
};
expert_module_t *expert_png;
int proto_png;
proto_png = proto_register_protocol("Portable Network Graphics","PNG","png");
hfi_png = proto_registrar_get_nth(proto_png);
proto_register_fields(proto_png, hfi, array_length(hfi));
proto_register_subtree_array(ett, array_length(ett));
expert_png = expert_register_protocol(proto_png);
expert_register_field_array(expert_png, ei, array_length(ei));
png_handle = register_dissector("png", dissect_png, proto_png);
}
static gboolean dissect_png_heur(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
return dissect_png(tvb, pinfo, tree, NULL) > 0;
}
void
proto_reg_handoff_png(void)
{
dissector_add_string("media_type", "image/png", png_handle);
heur_dissector_add("http", dissect_png_heur, "PNG file in HTTP", "png_http", hfi_png->id, HEURISTIC_ENABLE);
heur_dissector_add("wtap_file", dissect_png_heur, "PNG file in HTTP", "png_wtap", hfi_png->id, HEURISTIC_ENABLE);
}
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/