forked from osmocom/wireshark
![Michael Mann](/assets/img/avatar_default.png)
Started by grepping call_dissector_with_data, call_dissector_only and call_dissector and traced the handles passed into them to a find_dissector within the dissector. Then replaced find_dissector with find_dissector_add_dependency and added the protocol id from the dissector. "data" dissector was not considered to be a dependency. Change-Id: I15d0d77301306587ef8e7af5876e74231816890d Reviewed-on: https://code.wireshark.org/review/14509 Petri-Dish: Michael Mann <mmann78@netscape.net> Reviewed-by: Michael Mann <mmann78@netscape.net>
287 lines
9.4 KiB
C
287 lines
9.4 KiB
C
/* packet-hdmi.c
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* Routines for HDMI dissection
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* Copyright 2014 Martin Kaiser <martin@kaiser.cx>
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*
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* Wireshark - Network traffic analyzer
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* By Gerald Combs <gerald@wireshark.org>
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* Copyright 1998 Gerald Combs
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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/* this dissector handles I2C messages on the HDMI Display Data Channel (DDC)
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*
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* EDID (Extended Display Identification Data) messages are dissected here,
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* HDCP messages are passed on to the HDCP dissector
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*/
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#include "config.h"
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#include <epan/packet.h>
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void proto_register_hdmi(void);
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void proto_reg_handoff_hdmi(void);
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static int proto_hdmi = -1;
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static dissector_handle_t hdcp_handle;
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static gint ett_hdmi = -1;
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static gint ett_hdmi_edid = -1;
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static int hf_hdmi_addr = -1;
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static int hf_hdmi_edid_offset = -1;
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static int hf_hdmi_edid_hdr = -1;
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static int hf_hdmi_edid_manf_id = -1;
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static int hf_hdmi_edid_manf_prod_code = -1;
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static int hf_hdmi_edid_manf_serial = -1;
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static int hf_hdmi_edid_manf_week = -1;
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static int hf_hdmi_edid_mod_year = -1;
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static int hf_hdmi_edid_manf_year = -1;
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static int hf_hdmi_edid_version = -1;
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/* also called Source and Sink in the HDMI spec */
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#define ADDR_TRX "Transmitter"
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#define ADDR_RCV "Receiver"
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/* we use 8bit I2C addresses, including the direction bit */
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#define ADDR8_HDCP_WRITE 0x74 /* transmitter->receiver */
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#define ADDR8_HDCP_READ 0x75 /* r->t */
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#define ADDR8_EDID_WRITE 0xA0 /* t->r */
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#define ADDR8_EDID_READ 0xA1 /* r->t */
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#define HDCP_ADDR8(x) (x == ADDR8_HDCP_WRITE || x == ADDR8_HDCP_READ)
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static const value_string hdmi_addr[] = {
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{ ADDR8_HDCP_WRITE, "transmitter writes HDCP data for receiver" },
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{ ADDR8_HDCP_READ, "transmitter reads HDCP data from receiver" },
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{ ADDR8_EDID_WRITE, "EDID request" },
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{ ADDR8_EDID_READ, "EDID read" },
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{ 0, NULL }
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};
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#define EDID_HDR_VALUE G_GUINT64_CONSTANT(0x00ffffffffffff00)
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/* grab 5 bits, from bit n to n+4, from a big-endian number x
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map those bits to a capital letter such that A == 1, B == 2, ... */
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#define CAPITAL_LETTER(x, n) ('A'-1 + (((x) & (0x1F<<n)) >> n))
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/* dissect EDID data from the receiver
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return the offset after the dissected data */
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static gint
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dissect_hdmi_edid(tvbuff_t *tvb, gint offset, packet_info *pinfo, proto_tree *tree)
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{
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proto_item *yi;
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proto_tree *edid_tree;
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guint64 edid_hdr;
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guint16 manf_id;
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gchar manf_id_str[4]; /* 3 letters + 0-termination */
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guint8 week, year;
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int year_hf;
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edid_tree = proto_tree_add_subtree(tree, tvb,
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offset, -1, ett_hdmi_edid, NULL,
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"Extended Display Identification Data (EDID)");
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edid_hdr = tvb_get_ntoh64(tvb, offset);
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if (edid_hdr != EDID_HDR_VALUE)
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return offset; /* XXX handle fragmented EDID messages */
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col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "EDID");
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proto_tree_add_item(edid_tree, hf_hdmi_edid_hdr,
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tvb, offset, 8, ENC_LITTLE_ENDIAN);
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offset += 8;
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/* read as big endian for easier splitting */
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manf_id = tvb_get_ntohs(tvb, offset);
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/* XXX check that MSB is 0 */
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manf_id_str[0] = CAPITAL_LETTER(manf_id, 10);
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manf_id_str[1] = CAPITAL_LETTER(manf_id, 5);
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manf_id_str[2] = CAPITAL_LETTER(manf_id, 0);
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manf_id_str[3] = 0;
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proto_tree_add_string(edid_tree, hf_hdmi_edid_manf_id,
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tvb, offset, 2, manf_id_str);
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offset += 2;
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proto_tree_add_item(edid_tree, hf_hdmi_edid_manf_prod_code,
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tvb, offset, 2, ENC_LITTLE_ENDIAN);
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offset += 2;
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proto_tree_add_item(edid_tree, hf_hdmi_edid_manf_serial,
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tvb, offset, 4, ENC_LITTLE_ENDIAN);
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offset += 4;
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week = tvb_get_guint8(tvb, offset);
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proto_tree_add_item(edid_tree, hf_hdmi_edid_manf_week,
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tvb, offset, 1, ENC_LITTLE_ENDIAN);
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offset += 1;
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year_hf = week == 255 ? hf_hdmi_edid_mod_year : hf_hdmi_edid_manf_year;
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year = tvb_get_guint8(tvb, offset);
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yi = proto_tree_add_item(edid_tree, year_hf,
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tvb, offset, 1, ENC_LITTLE_ENDIAN);
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proto_item_append_text(yi, " (year %d)", 1990+year);
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offset += 1;
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proto_tree_add_item(edid_tree, hf_hdmi_edid_version, tvb, offset, 2, ENC_BIG_ENDIAN);
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/* XXX dissect the parts following the EDID header */
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return tvb_reported_length(tvb);
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}
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static int
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dissect_hdmi(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
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{
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guint8 addr;
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gint offset=0;
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proto_item *pi;
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proto_tree *hdmi_tree;
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/* the I2C address in the first byte is always handled by the HDMI
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dissector, even if the packet contains HDCP data */
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addr = tvb_get_guint8(tvb, 0);
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if (!try_val_to_str(addr, hdmi_addr))
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return 0; /* no HDMI packet */
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "HDMI");
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col_clear(pinfo->cinfo, COL_INFO);
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pi = proto_tree_add_item(tree, proto_hdmi, tvb, 0, -1, ENC_NA);
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hdmi_tree = proto_item_add_subtree(pi, ett_hdmi);
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if (addr&0x01) {
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set_address(&pinfo->src, AT_STRINGZ, (int)strlen(ADDR_RCV)+1, ADDR_RCV);
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set_address(&pinfo->dst, AT_STRINGZ, (int)strlen(ADDR_TRX)+1, ADDR_TRX);
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pinfo->p2p_dir = P2P_DIR_RECV;
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}
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else {
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set_address(&pinfo->src, AT_STRINGZ, (int)strlen(ADDR_TRX)+1, ADDR_TRX);
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set_address(&pinfo->dst, AT_STRINGZ, (int)strlen(ADDR_RCV)+1, ADDR_RCV);
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pinfo->p2p_dir = P2P_DIR_SENT;
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}
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/* there's no explicit statement in the spec saying that the protocol is
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big or little endian
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there's three cases: one byte values, symmetrical values or values
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that are explicitly marked as little endian
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for the sake of simplicity, we use little endian everywhere */
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proto_tree_add_item(hdmi_tree, hf_hdmi_addr, tvb, offset, 1, ENC_LITTLE_ENDIAN);
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offset += 1;
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if (HDCP_ADDR8(addr)) {
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tvbuff_t *hdcp_tvb;
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hdcp_tvb = tvb_new_subset_remaining(tvb, offset);
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return call_dissector(hdcp_handle, hdcp_tvb, pinfo, hdmi_tree);
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}
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if (addr == ADDR8_EDID_WRITE) {
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col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "EDID request");
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proto_tree_add_item(hdmi_tree, hf_hdmi_edid_offset,
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tvb, offset, 1, ENC_LITTLE_ENDIAN);
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offset += 1;
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return offset;
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}
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return dissect_hdmi_edid(tvb, offset, pinfo, hdmi_tree);
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}
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static void
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hdmi_fmt_edid_version( gchar *result, guint32 revision )
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{
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g_snprintf( result, ITEM_LABEL_LENGTH, "%d.%02d", (guint8)(( revision & 0xFF00 ) >> 8), (guint8)(revision & 0xFF) );
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}
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void
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proto_register_hdmi(void)
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{
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static hf_register_info hf[] = {
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{ &hf_hdmi_addr,
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{ "8bit I2C address", "hdmi.addr", FT_UINT8, BASE_HEX,
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VALS(hdmi_addr), 0, NULL, HFILL } },
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{ &hf_hdmi_edid_offset,
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{ "Offset", "hdmi.edid.offset",
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FT_UINT8, BASE_HEX, NULL, 0, NULL, HFILL } },
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{ &hf_hdmi_edid_hdr,
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{ "EDID header", "hdmi.edid.hdr",
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FT_UINT64, BASE_HEX, NULL, 0, NULL, HFILL } },
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{ &hf_hdmi_edid_manf_id,
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{ "Manufacturer ID", "hdmi.edid.manf_id",
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FT_STRING, STR_ASCII, NULL, 0, NULL, HFILL } },
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{ &hf_hdmi_edid_manf_prod_code,
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{ "Manufacturer product code", "hdmi.edid.manf_prod_code",
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FT_UINT16, BASE_HEX, NULL, 0, NULL, HFILL } },
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{ &hf_hdmi_edid_manf_serial,
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{ "Serial number", "hdmi.edid.serial_num",
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FT_UINT32, BASE_DEC, NULL, 0, NULL, HFILL } },
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{ &hf_hdmi_edid_manf_week,
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{ "Week of manufacture", "hdmi.edid.manf_week",
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FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL } },
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{ &hf_hdmi_edid_mod_year,
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{ "Model year", "hdmi.edid.model_year",
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FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL } },
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{ &hf_hdmi_edid_manf_year,
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{ "Year of manufacture", "hdmi.edid.manf_year",
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FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL } },
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{ &hf_hdmi_edid_version,
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{ "EDID Version", "hdmi.edid.version",
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FT_UINT16, BASE_CUSTOM, CF_FUNC(hdmi_fmt_edid_version), 0, NULL, HFILL } }
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};
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static gint *ett[] = {
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&ett_hdmi,
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&ett_hdmi_edid
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};
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proto_hdmi = proto_register_protocol(
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"High-Definition Multimedia Interface", "HDMI", "hdmi");
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proto_register_field_array(proto_hdmi, hf, array_length(hf));
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proto_register_subtree_array(ett, array_length(ett));
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}
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void
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proto_reg_handoff_hdmi(void)
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{
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dissector_handle_t hdmi_handle;
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hdcp_handle = find_dissector_add_dependency("hdcp", proto_hdmi);
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hdmi_handle = create_dissector_handle( dissect_hdmi, proto_hdmi );
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dissector_add_for_decode_as("i2c.message", hdmi_handle );
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}
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/*
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* Editor modelines - http://www.wireshark.org/tools/modelines.html
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*
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* Local variables:
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* c-basic-offset: 4
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* tab-width: 8
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* indent-tabs-mode: nil
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* End:
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*
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* vi: set shiftwidth=4 tabstop=8 expandtab:
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* :indentSize=4:tabSize=8:noTabs=true:
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*/
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