diff options
Diffstat (limited to 'epan/dissectors/packet-image-jfif.c')
| -rw-r--r-- | epan/dissectors/packet-image-jfif.c | 1198 |
1 files changed, 1198 insertions, 0 deletions
diff --git a/epan/dissectors/packet-image-jfif.c b/epan/dissectors/packet-image-jfif.c new file mode 100644 index 0000000000..666584c84d --- /dev/null +++ b/epan/dissectors/packet-image-jfif.c @@ -0,0 +1,1198 @@ +/* packet-image-jfif.c + * + * Routines for JFIF image/jpeg media dissection + * Copyright 2004, Olivier Biot. + * + * $Id$ + * + * Refer to the AUTHORS file or the AUTHORS section in the man page + * for contacting the author(s) of this file. + * + * Ethereal - Network traffic analyzer + * By Gerald Combs <gerald@ethereal.com> + * Copyright 1998 Gerald Combs + * + * JFIF media decoding functionality provided by Olivier Biot. + * + * The JFIF specifications are found at several locations, such as: + * http://www.jpeg.org/public/jfif.pdf + * http://www.w3.org/Graphics/JPEG/itu-t81.pdf + * + * The Exif specifications are found at several locations, such as: + * http://www.exif.org/ + * + * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +/* Edit this file with 4-space tabulation */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include <glib.h> + +#ifdef NEED_SNPRINTF_H +# include "snprintf.h" +#endif + +#include <epan/packet.h> + +/* General-purpose debug logger. + * Requires double parentheses because of variable arguments of printf(). + * + * Enable debug logging for JFIF by defining AM_CFLAGS + * so that it contains "-DDEBUG_image_jfif" or "-DDEBUG_image" + */ +#if (defined(DEBUG_image_jfif) || defined(DEBUG_image)) +#define DebugLog(x) \ + printf("%s:%u: ", __FILE__, __LINE__); \ + printf x; \ + fflush(stdout) +#else +#define DebugLog(x) ; +#endif + +#define PLURALIZE(x) ((x) == 1 ? "" : "s") + +#define IMG_JFIF "image-jfif" + +/************************** Variable declarations **************************/ + +#define MARKER_TEM 0xFF01 + +/* 0xFF02 -- 0xFFBF are reserved */ + +#define MARKER_SOF0 0xFFC0 +#define MARKER_SOF1 0xFFC1 +#define MARKER_SOF2 0xFFC2 +#define MARKER_SOF3 0xFFC3 + +#define MARKER_DHT 0xFFC4 + +#define MARKER_SOF5 0xFFC5 +#define MARKER_SOF6 0xFFC6 +#define MARKER_SOF7 0xFFC7 +#define MARKER_SOF8 0xFFC8 +#define MARKER_SOF9 0xFFC9 +#define MARKER_SOF10 0xFFCA +#define MARKER_SOF11 0xFFCB + +#define MARKER_DAC 0xFFCC + +#define MARKER_SOF13 0xFFCD +#define MARKER_SOF14 0xFFCE +#define MARKER_SOF15 0xFFCF + +#define MARKER_RST0 0xFFD0 +#define MARKER_RST1 0xFFD1 +#define MARKER_RST2 0xFFD2 +#define MARKER_RST3 0xFFD3 +#define MARKER_RST4 0xFFD4 +#define MARKER_RST5 0xFFD5 +#define MARKER_RST6 0xFFD6 +#define MARKER_RST7 0xFFD7 + +#define MARKER_FFDB 0xFFDB +#define MARKER_SOI 0xFFD8 +#define MARKER_EOI 0xFFD9 +#define MARKER_SOS 0xFFDA +#define MARKER_DQT 0xFFDB +#define MARKER_DNL 0xFFDC +#define MARKER_DRI 0xFFDD +#define MARKER_DHP 0xFFDE +#define MARKER_EXP 0xFFDF + +#define MARKER_APP0 0xFFE0 +#define MARKER_APP1 0xFFE1 +#define MARKER_APP2 0xFFE2 +#define MARKER_APP3 0xFFE3 +#define MARKER_APP4 0xFFE4 +#define MARKER_APP5 0xFFE5 +#define MARKER_APP6 0xFFE6 +#define MARKER_APP7 0xFFE7 +#define MARKER_APP8 0xFFE8 +#define MARKER_APP9 0xFFE9 +#define MARKER_APP10 0xFFEA +#define MARKER_APP11 0xFFEB +#define MARKER_APP12 0xFFEC +#define MARKER_APP13 0xFFED +#define MARKER_APP14 0xFFEE +#define MARKER_APP15 0xFFEF + +#define MARKER_JPG0 0xFFF0 +#define MARKER_JPG1 0xFFF1 +#define MARKER_JPG2 0xFFF2 +#define MARKER_JPG3 0xFFF3 +#define MARKER_JPG4 0xFFF4 +#define MARKER_JPG5 0xFFF5 +#define MARKER_JPG6 0xFFF6 +#define MARKER_JPG7 0xFFF7 +#define MARKER_JPG8 0xFFF8 +#define MARKER_JPG9 0xFFF9 +#define MARKER_JPG10 0xFFFA +#define MARKER_JPG11 0xFFFB +#define MARKER_JPG12 0xFFFC +#define MARKER_JPG13 0xFFFD + +#define MARKER_COM 0xFFFE + +#define marker_has_length(marker) ( ! ( \ + ((marker) == MARKER_TEM) \ + || ((marker) == MARKER_SOI) \ + || ((marker) == MARKER_EOI) \ + || ( ((marker) >= MARKER_RST0) && ((marker) <= MARKER_RST7) ) \ + ) ) + + +static const value_string vals_marker[] = { + { MARKER_TEM, "Reserved - For temporary private use in arithmetic coding" }, + { MARKER_SOF0, "Start of Frame (non-differential, Huffman coding) - Baseline DCT" }, + { MARKER_SOF1, "Start of Frame (non-differential, Huffman coding) - Extended sequential DCT" }, + { MARKER_SOF2, "Start of Frame (non-differential, Huffman coding) - Progressive DCT" }, + { MARKER_SOF3, "Start of Frame (non-differential, Huffman coding) - Lossless (sequential)" }, + { MARKER_DHT, "Define Huffman table(s)" }, + { MARKER_SOF5, "Start of Frame (differential, Huffman coding) - Differential sequential DCT" }, + { MARKER_SOF6, "Start of Frame (differential, Huffman coding) - Differential progressive DCT" }, + { MARKER_SOF7, "Start of Frame (differential, Huffman coding) - Differential lossless (sequential)" }, + { MARKER_SOF8, "Start of Frame (non-differential, arithmetic coding) - Reserved for JPEG extensions" }, + { MARKER_SOF9, "Start of Frame (non-differential, arithmetic coding) - Extended sequential DCT" }, + { MARKER_SOF10, "Start of Frame (non-differential, arithmetic coding) - Progressive DCT" }, + { MARKER_SOF11, "Start of Frame (non-differential, arithmetic coding) - Lossless (sequential)" }, + { MARKER_DAC, "Define arithmetic coding conditioning(s)" }, + { MARKER_SOF13, "Start of Frame (differential, arithmetic coding) - Differential sequential DCT" }, + { MARKER_SOF14, "Start of Frame (differential, arithmetic coding) - Differential progressive DCT" }, + { MARKER_SOF15, "Start of Frame (differential, arithmetic coding) - Differential lossless (sequential)" }, + { MARKER_RST0, "Restart interval termination - Restart with modulo 8 count 0" }, + { MARKER_RST1, "Restart interval termination - Restart with modulo 8 count 1" }, + { MARKER_RST2, "Restart interval termination - Restart with modulo 8 count 2" }, + { MARKER_RST3, "Restart interval termination - Restart with modulo 8 count 3" }, + { MARKER_RST4, "Restart interval termination - Restart with modulo 8 count 4" }, + { MARKER_RST5, "Restart interval termination - Restart with modulo 8 count 5" }, + { MARKER_RST6, "Restart interval termination - Restart with modulo 8 count 6" }, + { MARKER_RST7, "Restart interval termination - Restart with modulo 8 count 7" }, + { MARKER_SOI, "Start of Image" }, + { MARKER_EOI, "End of Image" }, + { MARKER_SOS, "Start of Scan" }, + { MARKER_DQT, "Define quantization table(s)" }, + { MARKER_DNL, "Define number of lines" }, + { MARKER_DRI, "Define restart interval" }, + { MARKER_DHP, "Define hierarchical progression" }, + { MARKER_EXP, "Expand reference component(s)" }, + { MARKER_APP0, "Reserved for application segments - 0" }, + { MARKER_APP1, "Reserved for application segments - 1" }, + { MARKER_APP2, "Reserved for application segments - 2" }, + { MARKER_APP3, "Reserved for application segments - 3" }, + { MARKER_APP4, "Reserved for application segments - 4" }, + { MARKER_APP5, "Reserved for application segments - 5" }, + { MARKER_APP6, "Reserved for application segments - 6" }, + { MARKER_APP7, "Reserved for application segments - 7" }, + { MARKER_APP8, "Reserved for application segments - 8" }, + { MARKER_APP9, "Reserved for application segments - 9" }, + { MARKER_APP10, "Reserved for application segments - 10" }, + { MARKER_APP11, "Reserved for application segments - 11" }, + { MARKER_APP12, "Reserved for application segments - 12" }, + { MARKER_APP13, "Reserved for application segments - 13" }, + { MARKER_APP14, "Reserved for application segments - 14" }, + { MARKER_APP15, "Reserved for application segments - 15" }, + { MARKER_JPG0, "Reserved for JPEG extensions - 0" }, + { MARKER_JPG1, "Reserved for JPEG extensions - 1" }, + { MARKER_JPG2, "Reserved for JPEG extensions - 2" }, + { MARKER_JPG3, "Reserved for JPEG extensions - 3" }, + { MARKER_JPG4, "Reserved for JPEG extensions - 4" }, + { MARKER_JPG5, "Reserved for JPEG extensions - 5" }, + { MARKER_JPG6, "Reserved for JPEG extensions - 6" }, + { MARKER_JPG7, "Reserved for JPEG extensions - 7" }, + { MARKER_JPG8, "Reserved for JPEG extensions - 8" }, + { MARKER_JPG9, "Reserved for JPEG extensions - 9" }, + { MARKER_JPG10, "Reserved for JPEG extensions - 10" }, + { MARKER_JPG11, "Reserved for JPEG extensions - 11" }, + { MARKER_JPG12, "Reserved for JPEG extensions - 12" }, + { MARKER_JPG13, "Reserved for JPEG extensions - 13" }, + { 0x00, NULL } +}; + +static const value_string vals_units[] = { + { 0, "No units; Xdensity and Ydensity specify the pixel aspect ratio" }, + { 1, "Dots per inch" }, + { 2, "Dots per centimeter" }, + { 0x00, NULL } +}; + +static const value_string vals_extension_code[] = { + { 0x10, "Thumbnail encoded using JPEG" }, + { 0x11, "Thumbnail encoded using 1 byte (8 bits) per pixel" }, + { 0x13, "Thumbnail encoded using 3 bytes (24 bits) per pixel" }, + { 0x00, NULL } +}; + +static const value_string vals_exif_tags[] = { + /* + * Tags related to image data structure: + */ + { 0x0100, "ImageWidth" }, + { 0x0101, "ImageLength" }, + { 0x0102, "BitsPerSample" }, + { 0x0103, "Compression" }, + { 0x0106, "PhotometricInterpretation" }, + { 0x0112, "Orientation" }, + { 0x0115, "SamplesPerPixel" }, + { 0x011C, "PlanarConfiguration" }, + { 0x0212, "YCbCrSubSampling" }, + { 0x0213, "YCbCrPositioning" }, + { 0x011A, "XResolution" }, + { 0x011B, "YResolution" }, + { 0x0128, "ResolutionUnit" }, + /* + * Tags relating to recording offset: + */ + { 0x0111, "StripOffsets" }, + { 0x0116, "RowsPerStrip" }, + { 0x0117, "StripByteCounts" }, + { 0x0201, "JPEGInterchangeFormat" }, + { 0x0202, "JPEGInterchangeFormatLength" }, + /* + * Tags relating to image data characteristics: + */ + { 0x012D, "TransferFunction" }, + { 0x013E, "WhitePoint" }, + { 0x013F, "PrimaryChromaticities" }, + { 0x0211, "YCbCrCoefficients" }, + { 0x0214, "ReferenceBlackWhite" }, + /* + * Other tags: + */ + { 0x0132, "DateTime" }, + { 0x010E, "ImageDescription" }, + { 0x010F, "Make" }, + { 0x0110, "Model" }, + { 0x0131, "Software" }, + { 0x013B, "Artist" }, + { 0x8296, "Copyright" }, + /* + * Exif-specific IFD: + */ + { 0x8769, "Exif IFD Pointer"}, + { 0x8825, "GPS IFD Pointer"}, + { 0xA005, "Interoperability IFD Pointer"}, + + { 0x0000, NULL } +}; + +static const value_string vals_exif_types[] = { + { 0x0001, "BYTE" }, + { 0x0002, "ASCII" }, + { 0x0003, "SHORT" }, + { 0x0004, "LONG" }, + { 0x0005, "RATIONAL" }, + /* 0x0006 */ + { 0x0007, "UNDEFINED" }, + /* 0x0008 */ + { 0x0009, "SLONG" }, + { 0x000A, "SRATIONAL" }, + + { 0x0000, NULL } +}; + +/* Initialize the protocol and registered fields */ +static int proto_jfif = -1; + +/* Marker */ +static gint hf_marker = -1; +/* Marker segment */ +static gint hf_marker_segment = -1; +static gint hf_len = -1; +/* MARKER_APP0 */ +static gint hf_identifier = -1; +/* MARKER_APP0 - JFIF */ +static gint hf_version = -1; +static gint hf_version_major = -1; +static gint hf_version_minor = -1; +static gint hf_units = -1; +static gint hf_xdensity = -1; +static gint hf_ydensity = -1; +static gint hf_xthumbnail = -1; +static gint hf_ythumbnail = -1; +static gint hf_rgb = -1; +/* MARKER_APP0 - JFXX */ +static gint hf_extension_code = -1; +/* start of Frame */ +static gint hf_sof_header = -1; +static gint hf_sof_precision = -1; +static gint hf_sof_lines = -1; +static gint hf_sof_samples_per_line = -1; +static gint hf_sof_nf = -1; +static gint hf_sof_c_i = -1; +static gint hf_sof_h_i = -1; +static gint hf_sof_v_i = -1; +static gint hf_sof_tq_i = -1; + +/* Start of Scan */ +static gint hf_sos_header = -1; +static gint hf_sos_ns = -1; +static gint hf_sos_cs_j = -1; +static gint hf_sos_td_j = -1; +static gint hf_sos_ta_j = -1; +static gint hf_sos_ss = -1; +static gint hf_sos_se = -1; +static gint hf_sos_ah = -1; +static gint hf_sos_al = -1; + +/* Initialize the subtree pointers */ +static gint ett_jfif = -1; +static gint ett_marker_segment = -1; +static gint ett_details = -1; + + +/**************** GIF related declarations and definitions ****************/ + + +/************************** Function prototypes **************************/ + + +static void +dissect_jfif(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree); + +void +proto_register_jfif(void); + + + +/****************** JFIF protocol dissection functions ******************/ + +#define ErrorInvalidJFIF "This is not a valid JFIF (JPEG) object" + + +/* + * Process a marker segment (with length). + */ +static void +process_marker_segment(proto_tree *tree, tvbuff_t *tvb, guint32 len, + guint16 marker, const char *marker_name) +{ + proto_item *ti = NULL; + proto_tree *subtree = NULL; + + if (! tree) + return; + + ti = proto_tree_add_item(tree, hf_marker_segment, + tvb, 0, -1, FALSE); + subtree = proto_item_add_subtree(ti, ett_marker_segment); + + proto_item_append_text(ti, ": %s (0x%04X)", marker_name, marker); + proto_tree_add_item(subtree, hf_marker, tvb, 0, 2, FALSE); + + proto_tree_add_item(subtree, hf_len, tvb, 2, 2, FALSE); + + proto_tree_add_text(subtree, tvb, 4, -1, + "Remaining segment data (%u bytes)", len - 2); +} + +/* + * Process a Start of Frame header (with length). + */ +static void +process_sof_header(proto_tree *tree, tvbuff_t *tvb, guint32 len _U_, + guint16 marker, const char *marker_name) +{ + proto_item *ti = NULL; + proto_tree *subtree = NULL; + + if (! tree) + return; + + ti = proto_tree_add_item(tree, hf_sof_header, + tvb, 0, -1, FALSE); + subtree = proto_item_add_subtree(ti, ett_marker_segment); + + proto_item_append_text(ti, ": %s (0x%04X)", marker_name, marker); + proto_tree_add_item(subtree, hf_marker, tvb, 0, 2, FALSE); + + proto_tree_add_item(subtree, hf_len, tvb, 2, 2, FALSE); + + proto_tree_add_item(subtree, hf_sof_precision, tvb, 4, 1, FALSE); + + proto_tree_add_item(subtree, hf_sof_lines, tvb, 5, 2, FALSE); + + proto_tree_add_item(subtree, hf_sof_samples_per_line, tvb, 7, 2, FALSE); + + proto_tree_add_item(subtree, hf_sof_nf, tvb, 9, 1, FALSE); + { + guint8 count = tvb_get_guint8(tvb, 9); + guint32 offset = 10; + while (count > 0) { + proto_tree_add_item(subtree, hf_sof_c_i, tvb, offset++, 1, FALSE); + proto_tree_add_item(subtree, hf_sof_h_i, tvb, offset, 1, FALSE); + proto_tree_add_item(subtree, hf_sof_v_i, tvb, offset++, 1, FALSE); + proto_tree_add_item(subtree, hf_sof_tq_i, tvb, offset++, 1, FALSE); + count--; + } + } +} + +/* + * Process a Start of Segment header (with length). + */ +static void +process_sos_header(proto_tree *tree, tvbuff_t *tvb, guint32 len _U_, + guint16 marker, const char *marker_name) +{ + proto_item *ti = NULL; + proto_tree *subtree = NULL; + guint32 offset; + + if (! tree) + return; + + ti = proto_tree_add_item(tree, hf_sos_header, + tvb, 0, -1, FALSE); + subtree = proto_item_add_subtree(ti, ett_marker_segment); + + proto_item_append_text(ti, ": %s (0x%04X)", marker_name, marker); + proto_tree_add_item(subtree, hf_marker, tvb, 0, 2, FALSE); + + proto_tree_add_item(subtree, hf_len, tvb, 2, 2, FALSE); + + proto_tree_add_item(subtree, hf_sos_ns, tvb, 4, 1, FALSE); + { + guint8 count = tvb_get_guint8(tvb, 4); + offset = 5; + while (count > 0) { + proto_tree_add_item(subtree, hf_sos_cs_j, tvb, offset++, 1, FALSE); + proto_tree_add_item(subtree, hf_sos_td_j, tvb, offset, 1, FALSE); + proto_tree_add_item(subtree, hf_sos_ta_j, tvb, offset++, 1, FALSE); + count--; + } + } + + proto_tree_add_item(subtree, hf_sos_ss, tvb, offset++, 1, FALSE); + proto_tree_add_item(subtree, hf_sos_se, tvb, offset++, 1, FALSE); + + proto_tree_add_item(subtree, hf_sos_ah, tvb, offset, 1, FALSE); + proto_tree_add_item(subtree, hf_sos_al, tvb, offset++, 1, FALSE); +} + +/* Process an APP0 block. + * + * XXX - This code only works on US-ASCII systems!!! + */ +static void +process_app0_segment(proto_tree *tree, tvbuff_t *tvb, guint32 len, + guint16 marker, const char *marker_name) +{ + proto_item *ti = NULL; + proto_tree *subtree = NULL; + proto_tree *subtree_details = NULL; + guint32 offset; + char *str; + gint str_size; + + if (!tree) + return; + + ti = proto_tree_add_item(tree, hf_marker_segment, + tvb, 0, -1, FALSE); + subtree = proto_item_add_subtree(ti, ett_marker_segment); + + proto_item_append_text(ti, ": %s (0x%04X)", marker_name, marker); + proto_tree_add_item(subtree, hf_marker, tvb, 0, 2, FALSE); + + proto_tree_add_item(subtree, hf_len, tvb, 2, 2, FALSE); + + str = tvb_get_stringz(tvb, 4, &str_size); + ti = proto_tree_add_item(subtree, hf_identifier, tvb, 4, str_size, FALSE); + if (strcmp(str, "JFIF") == 0) { + /* Version */ + ti = proto_tree_add_none_format(subtree, hf_version, + tvb, 9, 2, "Version: %u.%u", + tvb_get_guint8(tvb, 9), + tvb_get_guint8(tvb, 10)); + subtree_details = proto_item_add_subtree(ti, ett_details); + proto_tree_add_item(subtree_details, hf_version_major, + tvb, 9, 1, FALSE); + proto_tree_add_item(subtree_details, hf_version_minor, + tvb, 10, 1, FALSE); + + proto_tree_add_item(subtree, hf_units, + tvb, 11, 1, FALSE); + + /* Aspect ratio */ + proto_tree_add_item(subtree, hf_xdensity, + tvb, 12, 2, FALSE); + proto_tree_add_item(subtree, hf_ydensity, + tvb, 14, 2, FALSE); + + /* Thumbnail */ + proto_tree_add_item(subtree, hf_xthumbnail, + tvb, 16, 1, FALSE); + proto_tree_add_item(subtree, hf_ythumbnail, + tvb, 17, 1, FALSE); + { + guint16 x = tvb_get_guint8(tvb, 16); + guint16 y = tvb_get_guint8(tvb, 17); + if (x || y) { + proto_tree_add_item(subtree, hf_rgb, + tvb, 18, 3 * (x * y), FALSE); + offset = 18 + (3 * (x * y)); + } else { + offset = 18; + } + } + } else if (strcmp(str, "JFXX") == 0) { + proto_tree_add_item(subtree, hf_extension_code, + tvb, 9, 1, FALSE); + { + guint8 code = tvb_get_guint8(tvb, 9); + switch (code) { + case 0x10: /* Thumbnail coded using JPEG */ + break; + case 0x11: /* thumbnail stored using 1 byte per pixel */ + break; + case 0x13: /* thumbnail stored using 3 bytes per pixel */ + break; + default: /* Error */ + break; + } + } + } else { /* Unknown */ + proto_item_append_text(ti, " (unknown identifier)"); + offset = 4 + str_size; + + proto_tree_add_text(subtree, tvb, offset, -1, + "Remaining segment data (%u bytes)", len - 2 - str_size); + } + + return; +} + +/* Process an APP1 block. + * + * XXX - This code only works on US-ASCII systems!!! + */ +static void +process_app1_segment(proto_tree *tree, tvbuff_t *tvb, guint32 len, + guint16 marker, const char *marker_name) +{ + proto_item *ti = NULL; + proto_tree *subtree = NULL; + proto_tree *subtree_details = NULL; + char *str; + gint str_size; + guint32 offset, tiff_start; + + if (!tree) + return; + + ti = proto_tree_add_item(tree, hf_marker_segment, + tvb, 0, -1, FALSE); + subtree = proto_item_add_subtree(ti, ett_marker_segment); + + proto_item_append_text(ti, ": %s (0x%04X)", marker_name, marker); + proto_tree_add_item(subtree, hf_marker, tvb, 0, 2, FALSE); + + proto_tree_add_item(subtree, hf_len, tvb, 2, 2, FALSE); + + str = tvb_get_stringz(tvb, 4, &str_size); + ti = proto_tree_add_item(subtree, hf_identifier, tvb, 4, str_size, FALSE); + offset = tiff_start = 4 + str_size; + if (strcmp(str, "Exif") == 0) { + /* + * Endianness + */ + gboolean is_little_endian; + guint16 val_16; + guint32 val_32; + guint16 num_fields; + + offset++; /* Skip a byte supposed to be 0x00 */ + + val_16 = tvb_get_ntohs(tvb, offset); + if (val_16 == 0x4949) { + is_little_endian = TRUE; + proto_tree_add_text(subtree, tvb, offset, 2, "Endianness: little endian"); + } else if (val_16 == 0x4D4D) { + is_little_endian = FALSE; + proto_tree_add_text(subtree, tvb, offset, 2, "Endianness: big endian"); + } else { + /* Error: invalid endianness encoding */ + proto_tree_add_text(subtree, tvb, offset, 2, + "Incorrect endianness encoding - skipping the remainder of this application marker"); + return; + } + offset += 2; + /* + * Fixed value 42 = 0x002a + */ + offset += 2; + /* + * Offset to IFD + */ + if (is_little_endian) { + val_16 = tvb_get_letohs(tvb, offset); + } else { + val_16 = tvb_get_ntohs(tvb, offset); + } + proto_tree_add_text(subtree, tvb, offset, 4, + "Start offset of IFD starting from the TIFF header start: %u bytes", val_16); + offset += 4; + /* + * Skip the following portion + */ + proto_tree_add_text(subtree, tvb, offset, val_16 + tiff_start - offset, + "Skipped data between end of TIFF header and start of IFD (%u bytes)", + val_16 + tiff_start - offset); + offset = val_16 + tiff_start + 1; + /* + * Process the "0th" IFD + */ + if (is_little_endian) { + num_fields = tvb_get_letohs(tvb, offset); + } else { + num_fields = tvb_get_ntohs(tvb, offset); + } + proto_tree_add_text(subtree, tvb, offset, 2, "Number of fields in this IFD: %u", num_fields); + offset += 2; + while (num_fields-- > 0) { + guint16 tag, type; + guint32 count, off; + + if (is_little_endian) { + tag = tvb_get_letohs(tvb, offset); + type = tvb_get_letohs(tvb, offset + 2); + count = tvb_get_letohl(tvb, offset + 4); + off = tvb_get_letohl(tvb, offset + 8); + } else { + tag = tvb_get_ntohs(tvb, offset); + type = tvb_get_ntohs(tvb, offset + 2); + count = tvb_get_ntohl(tvb, offset + 4); + off = tvb_get_ntohl(tvb, offset + 8); + } + /* TODO - refine this */ + proto_tree_add_text(subtree, tvb, offset, 2, + "Exif Tag: 0x%04X (%s), Type: %u (%s), Count: %u, " + "Value offset from start of TIFF header: %u", + tag, val_to_str(tag, vals_exif_tags, "Unknown Exif tag"), + type, val_to_str(type, vals_exif_types, "Unknown Exif type"), + count, off); + offset += 12; + } + /* + * Offset to the "1st" IFD + */ + if (is_little_endian) { + val_32 = tvb_get_letohl(tvb, offset); + } else { + val_32 = tvb_get_ntohl(tvb, offset); + } + proto_tree_add_text(subtree, tvb, offset, 4, + "Offset to next IFD from start of TIFF header: %u bytes", val_32); + /* TODO - Continue parsing the "1th" IFD */ + offset += 4; + proto_tree_add_text(subtree, tvb, offset, -1, "Remainder of APP1 marker skipped"); + } else { + proto_item_append_text(ti, " (Unknown identifier)"); + } +} + +/* Process an APP2 block. + * + * XXX - This code only works on US-ASCII systems!!! + */ +static void +process_app2_segment(proto_tree *tree, tvbuff_t *tvb, guint32 len, + guint16 marker, const char *marker_name) +{ + proto_item *ti = NULL; + proto_tree *subtree = NULL; + proto_tree *subtree_details = NULL; + char *str; + gint str_size; + + if (!tree) + return; + + ti = proto_tree_add_item(tree, hf_marker_segment, + tvb, 0, -1, FALSE); + subtree = proto_item_add_subtree(ti, ett_marker_segment); + + proto_item_append_text(ti, ": %s (0x%04X)", marker_name, marker); + proto_tree_add_item(subtree, hf_marker, tvb, 0, 2, FALSE); + + proto_tree_add_item(subtree, hf_len, tvb, 2, 2, FALSE); + + str = tvb_get_stringz(tvb, 4, &str_size); + ti = proto_tree_add_item(subtree, hf_identifier, tvb, 4, str_size, FALSE); + if (strcmp(str, "FPXR") == 0) { + proto_tree_add_text(tree, tvb, 0, -1, "Exif FlashPix APP2 application marker"); + } else { + proto_item_append_text(ti, " (Unknown identifier)"); + } +} + +static void +dissect_jfif(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree) +{ + proto_tree *subtree = NULL; + proto_item *ti; + guint tvb_len = tvb_reported_length(tvb); + guint32 offset = 0; + tvbuff_t *tmp_tvb; + guint32 len; + guint16 marker; + + /* Add summary to INFO column if it is enabled */ + if (check_col(pinfo->cinfo, COL_INFO)) + col_append_sep_fstr(pinfo->cinfo, COL_INFO, " ", "(JPEG JFIF image)"); + + if (tree) { + ti = proto_tree_add_item(tree, proto_jfif, + tvb, 0, -1, FALSE); + subtree = proto_item_add_subtree(ti, ett_jfif); + } + + marker = tvb_get_ntohs(tvb, 0); + if (marker != MARKER_SOI) { + if (tree) { + proto_tree_add_text(subtree, tvb, 0, 2, ErrorInvalidJFIF); + return; + } + } + if (tree) + proto_tree_add_item(subtree, hf_marker, tvb, 0, 2, FALSE); + + offset = 2; + + /* + * Process the remaining markers and marker segments + */ + while (offset < tvb_len) { + char *str; + marker = tvb_get_ntohs(tvb, offset); + str = match_strval(marker, vals_marker); + if (str) { /* Known marker */ + if (marker_has_length(marker)) { /* Marker segment */ + /* Length of marker segment = 2 + len */ + len = tvb_get_ntohs(tvb, offset + 2); + tmp_tvb = tvb_new_subset(tvb, offset, 2 + len, 2 + len); + switch (marker) { + case MARKER_APP0: + process_app0_segment(subtree, tmp_tvb, len, marker, str); + break; + case MARKER_APP1: + process_app1_segment(subtree, tmp_tvb, len, marker, str); + break; + case MARKER_APP2: + process_app2_segment(subtree, tmp_tvb, len, marker, str); + break; + case MARKER_SOF0: + case MARKER_SOF1: + case MARKER_SOF2: + case MARKER_SOF3: + case MARKER_SOF5: + case MARKER_SOF6: + case MARKER_SOF7: + case MARKER_SOF8: + case MARKER_SOF9: + case MARKER_SOF10: + case MARKER_SOF11: + case MARKER_SOF13: + case MARKER_SOF14: + case MARKER_SOF15: + process_sof_header(subtree, tmp_tvb, len, marker, str); + break; + case MARKER_SOS: + process_sos_header(subtree, tmp_tvb, len, marker, str); + /* + * TODO - dissect a scan; the scan data is encoded. + */ + proto_tree_add_text(subtree, tvb, offset + 2 + len, -1, + "JFIF dissection stops here (dissection of a scan is not yet implemented)"); + return; + break; + default: + process_marker_segment(subtree, tmp_tvb, len, marker, str); + break; + } + offset += 2 + len; + } else { /* Marker but no segment */ + /* Length = 2 */ + proto_tree_add_item(subtree, hf_marker, + tvb, offset, 2, FALSE); + offset += 2; + } + } else { /* Reserved! */ + ti = proto_tree_add_item(subtree, hf_marker, + tvb, offset, 2, FALSE); + proto_item_append_text(ti, " (Reserved)"); + return; + } + } + + return; +} + + +/****************** Register the protocol with Ethereal ******************/ + + +/* This format is required because a script is used to build the C function + * that calls the protocol registration. */ + +void +proto_register_jfif(void) +{ + /* + * Setup list of header fields. + */ + static hf_register_info hf[] = { + /* Marker */ + { &hf_marker, + { "Marker", + IMG_JFIF ".marker", + FT_UINT8, BASE_HEX, VALS(vals_marker), 0x00, + "JFIF Marker", + HFILL + } + }, + /* Marker segment */ + { &hf_marker_segment, + { "Marker segment", + IMG_JFIF "marker_segment", + FT_NONE, BASE_NONE, NULL, 0x00, + "Marker segment", + HFILL + } + }, + { &hf_len, + { "Length", + IMG_JFIF ".length", + FT_UINT16, BASE_DEC, 0, 0x00, + "Length of segment (including length field)", + HFILL + } + }, + /* MARKER_APP0 */ + { &hf_identifier, + { "Identifier", + IMG_JFIF ".identifier", + FT_STRINGZ, BASE_NONE, NULL, 0x00, + "Identifier of the segment", + HFILL + } + }, + /* MARKER_APP0 - JFIF */ + { &hf_version, + { "Version", + IMG_JFIF ".version", + FT_NONE, BASE_NONE, NULL, 0x00, + "JFIF Version", + HFILL + } + }, + { &hf_version_major, + { "Major Version", + IMG_JFIF ".version.major", + FT_UINT8, BASE_DEC, NULL, 0x00, + "JFIF Major Version", + HFILL + } + }, + { &hf_version_minor, + { "Minor Version", + IMG_JFIF ".version.minor", + FT_UINT8, BASE_DEC, NULL, 0x00, + "JFIF Minor Version", + HFILL + } + }, + { &hf_units, + { "Units", + IMG_JFIF ".units", + FT_UINT8, BASE_DEC, VALS(vals_units), 0x00, + "Units used in this segment", + HFILL + } + }, + { &hf_xdensity, + { "Xdensity", + IMG_JFIF ".Xdensity", + FT_UINT16, BASE_DEC, NULL, 0x00, + "Horizontal pixel density", + HFILL + } + }, + { &hf_ydensity, + { "Ydensity", + IMG_JFIF ".Ydensity", + FT_UINT16, BASE_DEC, NULL, 0x00, + "Vertical pixel density", + HFILL + } + }, + { &hf_xthumbnail, + { "Xthumbnail", + IMG_JFIF ".Xthumbnail", + FT_UINT16, BASE_DEC, NULL, 0x00, + "Thumbnail horizontal pixel count", + HFILL + } + }, + { &hf_ythumbnail, + { "Ythumbnail", + IMG_JFIF ".Ythumbnail", + FT_UINT16, BASE_DEC, NULL, 0x00, + "Thumbnail vertical pixel count", + HFILL + } + }, + { &hf_rgb, + { "RGB values of thumbnail pixels", + IMG_JFIF ".RGB", + FT_BYTES, BASE_NONE, NULL, 0x00, + "RGB values of the thumbnail pixels (24 bit per pixel, Xthumbnail x Ythumbnail pixels)", + HFILL + } + }, + /* MARKER_APP0 - JFXX */ + { &hf_extension_code, + { "Extension code", + IMG_JFIF ".extension.code", + FT_UINT8, BASE_HEX, VALS(vals_extension_code), 0x00, + "JFXX extension code for thumbnail encoding", + HFILL + } + }, + /* Header: Start of Frame (MARKER_SOF) */ + { &hf_sof_header, + { "Start of Frame header", + IMG_JFIF ".sof", + FT_NONE, BASE_NONE, NULL, 0x00, + "Start of Frame header", + HFILL + } + }, + { &hf_sof_precision, + { "Sample Precision (bits)", + IMG_JFIF ".sof.precision", + FT_UINT8, BASE_DEC, NULL, 0x00, + "Specifies the precision in bits for the samples of the components in the frame.", + HFILL + } + }, + { &hf_sof_lines, + { "Lines", + IMG_JFIF ".sof.lines", + FT_UINT16, BASE_DEC, NULL, 0x00, + "Specifies the maximum number of lines in the source image.", + HFILL + } + }, + { &hf_sof_samples_per_line, + { "Samples per line", + IMG_JFIF ".sof.samples_per_line", + FT_UINT16, BASE_DEC, NULL, 0x00, + "Specifies the maximum number of samples per line in the source image.", + HFILL + } + }, + { &hf_sof_nf, + { "Number of image components in frame", + IMG_JFIF ".sof.nf", + FT_UINT8, BASE_DEC, NULL, 0x00, + "Specifies the number of source image components in the frame.", + HFILL + } + }, + { &hf_sof_c_i, + { "Component identifier", + IMG_JFIF ".sof.c_i", + FT_UINT8, BASE_DEC, NULL, 0x00, + "Assigns a unique label to the ith component in the sequence " + "of frame component specification parameters.", + HFILL + } + }, + { &hf_sof_h_i, + { "Horizontal sampling factor", + IMG_JFIF ".sof.h_i", + FT_UINT8, BASE_DEC, NULL, 0xF0, + "Specifies the relationship between the component horizontal " + "dimension and maximum image dimension X.", + HFILL + } + }, + { &hf_sof_v_i, + { "Vertical sampling factor", + IMG_JFIF ".sof.v_i", + FT_UINT8, BASE_DEC, NULL, 0x0F, + "Specifies the relationship between the component vertical " + "dimension and maximum image dimension Y.", + HFILL + } + }, + { &hf_sof_tq_i, + { "Quantization table destination selector", + IMG_JFIF ".sof.tq_i", + FT_UINT8, BASE_DEC, NULL, 0x00, + "Specifies one of four possible quantization table " + "destinations from which the quantization table to use " + "for dequantization of DCT coefficients of component Ci " + "is retrieved.", + HFILL + } + }, + + /* Header: Start of Segment (MARKER_SOS) */ + { &hf_sos_header, + { "Start of Segment header", + IMG_JFIF ".header.sos", + FT_NONE, BASE_NONE, NULL, 0x00, + "Start of Segment header", + HFILL + } + }, + { &hf_sos_ns, + { "Number of image components in scan", + IMG_JFIF ".sos.ns", + FT_UINT8, BASE_DEC, NULL, 0x00, + "Specifies the number of source image components in the scan.", + HFILL + } + }, + { &hf_sos_cs_j, + { "Scan component selector", + IMG_JFIF ".sos.component_selector", + FT_UINT8, BASE_DEC, NULL, 0x00, + "Selects which of the Nf image components specified in the " + "frame parameters shall be the jth component in the scan.", + HFILL + } + }, + { &hf_sos_td_j, + { "DC entropy coding table destination selector", + IMG_JFIF ".sos.dc_entropy_selector", + FT_UINT8, BASE_DEC, NULL, 0xF0, + "Specifies one of four possible DC entropy coding table " + "destinations from which the entropy table needed " + "for decoding of the DC coefficients of component Csj " + "is retrieved.", + HFILL + } + }, + { &hf_sos_ta_j, + { "AC entropy coding table destination selector", + IMG_JFIF ".sos.ac_entropy_selector", + FT_UINT8, BASE_DEC, NULL, 0x0F, + "Specifies one of four possible AC entropy coding table " + "destinations from which the entropy table needed " + "for decoding of the AC coefficients of component Csj " + "is retrieved.", + HFILL + } + }, + { &hf_sos_ss, + { "Start of spectral or predictor selection", + IMG_JFIF ".sos.ss", + FT_UINT8, BASE_DEC, NULL, 0x00, + "In the DCT modes of operation, this parameter specifies the " + "first DCT coefficient in each block in zig-zag order which " + "shall be coded in the scan. This parameter shall be set to " + "zero for the sequential DCT processes. " + "In the lossless mode of operations this parameter is used " + "to select the predictor.", + HFILL + } + }, + { &hf_sos_se, + { "End of spectral selection", + IMG_JFIF ".sos.se", + FT_UINT8, BASE_DEC, NULL, 0x00, + "Specifies the last DCT coefficient in each block in zig-zag " + "order which shall be coded in the scan. This parameter shall " + "be set to 63 for the sequential DCT processes. " + "In the lossless mode of operations this parameter has no " + "meaning. It shall be set to zero.", + HFILL + } + }, + { &hf_sos_ah, + { "Successive approximation bit position high", + IMG_JFIF ".sos.ah", + FT_UINT8, BASE_DEC, NULL, 0xF0, + "This parameter specifies the point transform used in the " + "preceding scan (i.e. successive approximation bit position " + "low in the preceding scan) for the band of coefficients " + "specified by Ss and Se. This parameter shall be set to zero " + "for the first scan of each band of coefficients. " + "In the lossless mode of operations this parameter has no " + "meaning. It shall be set to zero.", + HFILL + } + }, + { &hf_sos_al, + { "Successive approximation bit position low or point transform", + IMG_JFIF ".sos.al", + FT_UINT8, BASE_DEC, NULL, 0x0F, + "In the DCT modes of operation this parameter specifies the " + "point transform, i.e. bit position low, used before coding " + "the band of coefficients specified by Ss and Se. " + "This parameter shall be set to zero for the sequential DCT " + "processes. In the lossless mode of operations, this " + "parameter specifies the point transform, Pt.", + HFILL + } + }, + }; + + /* Setup protocol subtree array */ + static gint *ett[] = { + &ett_jfif, + &ett_marker_segment, + &ett_details, + }; + + /* Register the protocol name and description */ + proto_jfif = proto_register_protocol( + "JPEG File Interchange Format", + "JFIF (JPEG) image", + IMG_JFIF + ); + + /* Required function calls to register the header fields + * and subtrees used */ + proto_register_field_array(proto_jfif, hf, array_length(hf)); + proto_register_subtree_array(ett, array_length(ett)); + + register_dissector("image-jfif", dissect_jfif, proto_jfif); +} + + +void +proto_reg_handoff_jfif(void) +{ + dissector_handle_t jfif_handle; + + jfif_handle = create_dissector_handle(dissect_jfif, proto_jfif); + + /* Register the GIF media type */ + dissector_add_string("media_type", "image/jfif", jfif_handle); + dissector_add_string("media_type", "image/jpg", jfif_handle); + dissector_add_string("media_type", "image/jpeg", jfif_handle); +} |