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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-10 20:34:10 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-10 20:34:10 +0000 |
commit | e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc (patch) | |
tree | 68cb5ef9081156392f1dd62a00c6ccc1451b93df /epan/dissectors/packet-hdmi.c | |
parent | Initial commit. (diff) | |
download | wireshark-e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc.tar.xz wireshark-e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc.zip |
Adding upstream version 4.2.2.upstream/4.2.2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'epan/dissectors/packet-hdmi.c')
-rw-r--r-- | epan/dissectors/packet-hdmi.c | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/epan/dissectors/packet-hdmi.c b/epan/dissectors/packet-hdmi.c new file mode 100644 index 0000000..366e798 --- /dev/null +++ b/epan/dissectors/packet-hdmi.c @@ -0,0 +1,271 @@ +/* packet-hdmi.c + * Routines for HDMI dissection + * Copyright 2014 Martin Kaiser <martin@kaiser.cx> + * + * Wireshark - Network traffic analyzer + * By Gerald Combs <gerald@wireshark.org> + * Copyright 1998 Gerald Combs + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +/* this dissector handles I2C messages on the HDMI Display Data Channel (DDC) + * + * EDID (Extended Display Identification Data) messages are dissected here, + * HDCP messages are passed on to the HDCP dissector + */ + +#include "config.h" + +#include <epan/packet.h> + +void proto_register_hdmi(void); +void proto_reg_handoff_hdmi(void); + +static int proto_hdmi = -1; + +static dissector_handle_t hdmi_handle; +static dissector_handle_t hdcp_handle; + +static gint ett_hdmi = -1; +static gint ett_hdmi_edid = -1; + +static int hf_hdmi_addr = -1; +static int hf_hdmi_edid_offset = -1; +static int hf_hdmi_edid_hdr = -1; +static int hf_hdmi_edid_manf_id = -1; +static int hf_hdmi_edid_manf_prod_code = -1; +static int hf_hdmi_edid_manf_serial = -1; +static int hf_hdmi_edid_manf_week = -1; +static int hf_hdmi_edid_mod_year = -1; +static int hf_hdmi_edid_manf_year = -1; +static int hf_hdmi_edid_version = -1; + + +/* also called Source and Sink in the HDMI spec */ +#define ADDR_TRX "Transmitter" +#define ADDR_RCV "Receiver" + +/* we use 8bit I2C addresses, including the direction bit */ +#define ADDR8_HDCP_WRITE 0x74 /* transmitter->receiver */ +#define ADDR8_HDCP_READ 0x75 /* r->t */ +#define ADDR8_EDID_WRITE 0xA0 /* t->r */ +#define ADDR8_EDID_READ 0xA1 /* r->t */ + +#define HDCP_ADDR8(x) (x == ADDR8_HDCP_WRITE || x == ADDR8_HDCP_READ) + +static const value_string hdmi_addr[] = { + { ADDR8_HDCP_WRITE, "transmitter writes HDCP data for receiver" }, + { ADDR8_HDCP_READ, "transmitter reads HDCP data from receiver" }, + + { ADDR8_EDID_WRITE, "EDID request" }, + { ADDR8_EDID_READ, "EDID read" }, + { 0, NULL } +}; + +#define EDID_HDR_VALUE G_GUINT64_CONSTANT(0x00ffffffffffff00) + +/* grab 5 bits, from bit n to n+4, from a big-endian number x + map those bits to a capital letter such that A == 1, B == 2, ... */ +#define CAPITAL_LETTER(x, n) ('A'-1 + (((x) & (0x1F<<n)) >> n)) + + +/* dissect EDID data from the receiver + return the offset after the dissected data */ +static gint +dissect_hdmi_edid(tvbuff_t *tvb, gint offset, packet_info *pinfo, proto_tree *tree) +{ + proto_item *yi; + proto_tree *edid_tree; + guint64 edid_hdr; + guint16 manf_id; + gchar manf_id_str[4]; /* 3 letters + 0-termination */ + guint8 week, year; + int year_hf; + + edid_tree = proto_tree_add_subtree(tree, tvb, + offset, -1, ett_hdmi_edid, NULL, + "Extended Display Identification Data (EDID)"); + + edid_hdr = tvb_get_ntoh64(tvb, offset); + if (edid_hdr != EDID_HDR_VALUE) + return offset; /* XXX handle fragmented EDID messages */ + + col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "EDID"); + + proto_tree_add_item(edid_tree, hf_hdmi_edid_hdr, + tvb, offset, 8, ENC_LITTLE_ENDIAN); + offset += 8; + + /* read as big endian for easier splitting */ + manf_id = tvb_get_ntohs(tvb, offset); + /* XXX check that MSB is 0 */ + manf_id_str[0] = CAPITAL_LETTER(manf_id, 10); + manf_id_str[1] = CAPITAL_LETTER(manf_id, 5); + manf_id_str[2] = CAPITAL_LETTER(manf_id, 0); + manf_id_str[3] = 0; + proto_tree_add_string(edid_tree, hf_hdmi_edid_manf_id, + tvb, offset, 2, manf_id_str); + offset += 2; + + proto_tree_add_item(edid_tree, hf_hdmi_edid_manf_prod_code, + tvb, offset, 2, ENC_LITTLE_ENDIAN); + offset += 2; + + proto_tree_add_item(edid_tree, hf_hdmi_edid_manf_serial, + tvb, offset, 4, ENC_LITTLE_ENDIAN); + offset += 4; + + week = tvb_get_guint8(tvb, offset); + proto_tree_add_item(edid_tree, hf_hdmi_edid_manf_week, + tvb, offset, 1, ENC_LITTLE_ENDIAN); + offset += 1; + + year_hf = week == 255 ? hf_hdmi_edid_mod_year : hf_hdmi_edid_manf_year; + year = tvb_get_guint8(tvb, offset); + yi = proto_tree_add_item(edid_tree, year_hf, + tvb, offset, 1, ENC_LITTLE_ENDIAN); + proto_item_append_text(yi, " (year %d)", 1990+year); + offset += 1; + + proto_tree_add_item(edid_tree, hf_hdmi_edid_version, tvb, offset, 2, ENC_BIG_ENDIAN); + + /* XXX dissect the parts following the EDID header */ + + return tvb_reported_length(tvb); +} + + +static int +dissect_hdmi(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) +{ + guint8 addr; + gint offset=0; + proto_item *pi; + proto_tree *hdmi_tree; + + /* the I2C address in the first byte is always handled by the HDMI + dissector, even if the packet contains HDCP data */ + addr = tvb_get_guint8(tvb, 0); + if (!try_val_to_str(addr, hdmi_addr)) + return 0; /* no HDMI packet */ + + col_set_str(pinfo->cinfo, COL_PROTOCOL, "HDMI"); + col_clear(pinfo->cinfo, COL_INFO); + + pi = proto_tree_add_item(tree, proto_hdmi, tvb, 0, -1, ENC_NA); + hdmi_tree = proto_item_add_subtree(pi, ett_hdmi); + + if (addr&0x01) { + set_address(&pinfo->src, AT_STRINGZ, (int)strlen(ADDR_RCV)+1, ADDR_RCV); + set_address(&pinfo->dst, AT_STRINGZ, (int)strlen(ADDR_TRX)+1, ADDR_TRX); + pinfo->p2p_dir = P2P_DIR_RECV; + } + else { + set_address(&pinfo->src, AT_STRINGZ, (int)strlen(ADDR_TRX)+1, ADDR_TRX); + set_address(&pinfo->dst, AT_STRINGZ, (int)strlen(ADDR_RCV)+1, ADDR_RCV); + pinfo->p2p_dir = P2P_DIR_SENT; + } + + /* there's no explicit statement in the spec saying that the protocol is + big or little endian + there's three cases: one byte values, symmetrical values or values + that are explicitly marked as little endian + for the sake of simplicity, we use little endian everywhere */ + proto_tree_add_item(hdmi_tree, hf_hdmi_addr, tvb, offset, 1, ENC_LITTLE_ENDIAN); + offset += 1; + + if (HDCP_ADDR8(addr)) { + tvbuff_t *hdcp_tvb; + + hdcp_tvb = tvb_new_subset_remaining(tvb, offset); + + return call_dissector(hdcp_handle, hdcp_tvb, pinfo, hdmi_tree); + } + + if (addr == ADDR8_EDID_WRITE) { + col_append_sep_str(pinfo->cinfo, COL_INFO, NULL, "EDID request"); + proto_tree_add_item(hdmi_tree, hf_hdmi_edid_offset, + tvb, offset, 1, ENC_LITTLE_ENDIAN); + offset += 1; + return offset; + } + + return dissect_hdmi_edid(tvb, offset, pinfo, hdmi_tree); +} + +static void +hdmi_fmt_edid_version( gchar *result, guint32 revision ) +{ + snprintf( result, ITEM_LABEL_LENGTH, "%d.%02d", (guint8)(( revision & 0xFF00 ) >> 8), (guint8)(revision & 0xFF) ); +} + +void +proto_register_hdmi(void) +{ + static hf_register_info hf[] = { + { &hf_hdmi_addr, + { "8bit I2C address", "hdmi.addr", FT_UINT8, BASE_HEX, + VALS(hdmi_addr), 0, NULL, HFILL } }, + { &hf_hdmi_edid_offset, + { "Offset", "hdmi.edid.offset", + FT_UINT8, BASE_HEX, NULL, 0, NULL, HFILL } }, + { &hf_hdmi_edid_hdr, + { "EDID header", "hdmi.edid.hdr", + FT_UINT64, BASE_HEX, NULL, 0, NULL, HFILL } }, + { &hf_hdmi_edid_manf_id, + { "Manufacturer ID", "hdmi.edid.manf_id", + FT_STRING, BASE_NONE, NULL, 0, NULL, HFILL } }, + { &hf_hdmi_edid_manf_prod_code, + { "Manufacturer product code", "hdmi.edid.manf_prod_code", + FT_UINT16, BASE_HEX, NULL, 0, NULL, HFILL } }, + { &hf_hdmi_edid_manf_serial, + { "Serial number", "hdmi.edid.serial_num", + FT_UINT32, BASE_DEC, NULL, 0, NULL, HFILL } }, + { &hf_hdmi_edid_manf_week, + { "Week of manufacture", "hdmi.edid.manf_week", + FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL } }, + { &hf_hdmi_edid_mod_year, + { "Model year", "hdmi.edid.model_year", + FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL } }, + { &hf_hdmi_edid_manf_year, + { "Year of manufacture", "hdmi.edid.manf_year", + FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL } }, + { &hf_hdmi_edid_version, + { "EDID Version", "hdmi.edid.version", + FT_UINT16, BASE_CUSTOM, CF_FUNC(hdmi_fmt_edid_version), 0, NULL, HFILL } } + + }; + + static gint *ett[] = { + &ett_hdmi, + &ett_hdmi_edid + }; + + proto_hdmi = proto_register_protocol("High-Definition Multimedia Interface", "HDMI", "hdmi"); + hdmi_handle = register_dissector("hdmi", dissect_hdmi, proto_hdmi ); + + proto_register_field_array(proto_hdmi, hf, array_length(hf)); + proto_register_subtree_array(ett, array_length(ett)); +} + + +void +proto_reg_handoff_hdmi(void) +{ + hdcp_handle = find_dissector_add_dependency("hdcp", proto_hdmi); + dissector_add_for_decode_as("i2c.message", hdmi_handle ); +} + +/* + * Editor modelines - https://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: + */ |