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wireshark/epan/dissectors/packet-i2c.c

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/* packet-i2c.c
* Routines for I2C captures (using libpcap extensions)
*
* Pigeon Point Systems <www.pigeonpoint.com>
*
* 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 <epan/packet.h>
#include <epan/capture_dissectors.h>
#include <epan/prefs.h>
#include <epan/decode_as.h>
#include <wiretap/wtap.h>
void proto_register_i2c(void);
void proto_reg_handoff_i2c(void);
static int proto_i2c = -1;
static int proto_i2c_event = -1;
static int proto_i2c_data = -1;
static int hf_i2c_bus = -1;
static int hf_i2c_event = -1;
static int hf_i2c_flags = -1;
static int hf_i2c_addr = -1;
static gint ett_i2c = -1;
static dissector_table_t subdissector_table;
/* I2C packet flags. */
#define I2C_FLAG_RD 0x00000001
#define I2C_FLAG_TEN 0x00000010
#define I2C_FLAG_REV_DIR_ADDR 0x00002000
#define I2C_FLAG_NOSTART 0x00004000
/* I2C events. */
#define I2C_EVENT_PROM_ON (1 << 0) /* Promiscuous mode: on */
#define I2C_EVENT_PROM_OFF (1 << 1) /* Promiscuous mode: off */
#define I2C_EVENT_ONLINE_ON (1 << 2) /* Online state: on */
#define I2C_EVENT_ONLINE_OFF (1 << 3) /* Online state: off */
#define I2C_EVENT_ATTACHED_ON (1 << 4) /* Attached state: on */
#define I2C_EVENT_ATTACHED_OFF (1 << 5) /* Attached state: off */
#define I2C_EVENT_PROM_OVFL_ON (1 << 6) /* Prom. queue overflow: on */
#define I2C_EVENT_PROM_OVFL_OFF (1 << 7) /* Prom. queue overflow: off */
#define I2C_EVENT_OVFL_ON (1 << 8) /* Queue overflow: on */
#define I2C_EVENT_OVFL_OFF (1 << 9) /* Queue overflow: off */
/* I2C errors. */
#define I2C_EVENT_ERR_DATA_LO (1 << 16) /* Unable to drive data LO */
#define I2C_EVENT_ERR_DATA_HI (1 << 17) /* Unable to drive data HI */
#define I2C_EVENT_ERR_CLOCK_LO (1 << 18) /* Unable to drive clock LO */
#define I2C_EVENT_ERR_CLOCK_HI (1 << 19) /* Unable to drive clock HI */
#define I2C_EVENT_ERR_CLOCK_TO (1 << 20) /* Clock low timeout */
#define I2C_EVENT_ERR_PHYS (1 << 21) /* The I2C bus controller
has been physically
disconnected from the bus */
#define I2C_EVENT_ERR_FAIL (1 << 22) /* Undiagnosed failure */
static void i2c_prompt(packet_info *pinfo _U_, gchar* result)
{
g_snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "Interpret I2C messages as");
}
static gpointer i2c_value(packet_info *pinfo _U_)
{
return 0;
}
static gboolean
capture_i2c(const guchar *pd _U_, int offset _U_, int len _U_, capture_packet_info_t *cpinfo, const union wtap_pseudo_header *pseudo_header)
{
if (pseudo_header->i2c.is_event) {
capture_dissector_increment_count(cpinfo, proto_i2c_event);
} else {
capture_dissector_increment_count(cpinfo, proto_i2c_data);
}
return TRUE;
}
static const char *
i2c_get_event_desc(guint32 event)
{
const char *desc;
switch (event & 0x0000ffff) {
case I2C_EVENT_PROM_ON:
desc = "Promiscuous mode is enabled";
break;
case I2C_EVENT_PROM_OFF:
desc = "Promiscuous mode is disabled";
break;
case I2C_EVENT_ONLINE_ON:
desc = "The I2C controller is operational";
break;
case I2C_EVENT_ONLINE_OFF:
desc = "The I2C controller is non-operational";
break;
case I2C_EVENT_ATTACHED_ON:
desc = "The I2C controller is attached to an I2C bus";
break;
case I2C_EVENT_ATTACHED_OFF:
desc = "The I2C controller is detached from an I2C bus";
if (event & I2C_EVENT_ERR_DATA_LO) {
desc = "The I2C controller is detached from an I2C bus: "
"unable to drive data LO";
} else if (event & I2C_EVENT_ERR_DATA_HI) {
desc = "The I2C controller is detached from an I2C bus: "
"unable to drive data HI";
} else if (event & I2C_EVENT_ERR_CLOCK_LO) {
desc = "The I2C controller is detached from an I2C bus: "
"unable to drive clock LO";
} else if (event & I2C_EVENT_ERR_CLOCK_HI) {
desc = "The I2C controller is detached from an I2C bus: "
"unable to drive clock HI";
} else if (event & I2C_EVENT_ERR_CLOCK_TO) {
desc = "The I2C controller is detached from an I2C bus: "
"clock low timeout";
} else if (event & I2C_EVENT_ERR_PHYS) {
desc = "The I2C controller is detached from an I2C bus: "
"the I2C bus controller has been physically "
"disconnected from the bus";
} else if (event & I2C_EVENT_ERR_FAIL) {
desc = "The I2C controller is detached from an I2C bus: "
"undiagnosed failure";
}
break;
case I2C_EVENT_PROM_OVFL_ON:
desc = "The incoming promiscuous data buffer has been overrun; "
"some data is lost";
break;
case I2C_EVENT_PROM_OVFL_OFF:
desc = "The incoming promiscuous data buffer is available";
break;
case I2C_EVENT_OVFL_ON:
desc = "The incoming I2C data buffer has been overrun; "
"some data is lost";
break;
case I2C_EVENT_OVFL_OFF:
desc = "The incoming I2C data buffer is available";
break;
default:
desc = "<unknown state event>";
break;
}
return desc;
}
static int
dissect_i2c(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
proto_item *ti;
proto_tree *i2c_tree;
guint8 is_event;
guint8 bus, addr;
guint32 flags;
flags = pinfo->pseudo_header->i2c.flags;
bus = pinfo->pseudo_header->i2c.bus;
col_add_fstr(pinfo->cinfo, COL_DEF_SRC, "I2C-%d", bus);
is_event = pinfo->pseudo_header->i2c.is_event;
if (is_event) {
addr = 0;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "I2C Event");
col_add_fstr(pinfo->cinfo, COL_DEF_DST, "----");
col_add_fstr(pinfo->cinfo, COL_INFO, "%s",
i2c_get_event_desc(flags));
} else {
/* Report 7-bit hardware address */
addr = tvb_get_guint8(tvb, 0) >> 1;
col_add_fstr(pinfo->cinfo, COL_PROTOCOL, "I2C %s",
(flags & I2C_FLAG_RD) ? "Read" : "Write");
col_add_fstr(pinfo->cinfo, COL_DEF_DST, "0x%02x", addr);
col_add_fstr(pinfo->cinfo, COL_INFO, "I2C %s, %d bytes",
(flags & I2C_FLAG_RD) ? "Read" : "Write", tvb_captured_length(tvb));
}
pinfo->ptype = PT_I2C;
ti = proto_tree_add_protocol_format(tree, proto_i2c, tvb, 0, -1,
"Inter-Integrated Circuit (%s)",
is_event ? "Event" : "Data");
i2c_tree = proto_item_add_subtree(ti, ett_i2c);
proto_tree_add_uint_format(i2c_tree, hf_i2c_bus, tvb, 0, 0, bus,
"Bus: I2C-%d", bus);
if (is_event) {
proto_tree_add_uint_format_value(i2c_tree, hf_i2c_event, tvb, 0, 0,
flags, "%s (0x%08x)",
i2c_get_event_desc(flags), flags);
} else {
proto_tree_add_uint_format_value(i2c_tree, hf_i2c_addr, tvb, 0, 1,
addr, "0x%02x%s", addr, addr ? "" : " (General Call)");
proto_tree_add_uint(i2c_tree, hf_i2c_flags, tvb, 0, 0, flags);
/* Functionality for choosing subdissector is controlled through Decode As as I2C doesn't
have a unique identifier to determine subdissector */
if (!dissector_try_uint(subdissector_table, 0, tvb, pinfo, tree))
{
call_data_dissector(tvb, pinfo, tree);
}
}
return tvb_captured_length(tvb);
}
void
proto_register_i2c(void)
{
static hf_register_info hf[] = {
{ &hf_i2c_bus, { "Bus ID", "i2c.bus", FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL }},
{ &hf_i2c_addr, { "Target address", "i2c.addr", FT_UINT8, BASE_HEX, NULL, 0, NULL, HFILL }},
{ &hf_i2c_event, { "Event", "i2c.event", FT_UINT32, BASE_HEX, NULL, 0, NULL, HFILL }},
{ &hf_i2c_flags, { "Flags", "i2c.flags", FT_UINT32, BASE_HEX, NULL, 0, NULL, HFILL }},
};
static gint *ett[] = {
&ett_i2c
};
module_t *m;
/* Decode As handling */
static build_valid_func i2c_da_build_value[1] = {i2c_value};
static decode_as_value_t i2c_da_values = {i2c_prompt, 1, i2c_da_build_value};
static decode_as_t i2c_da = {"i2c", "I2C Message", "i2c.message", 1, 0, &i2c_da_values, NULL, NULL,
decode_as_default_populate_list, decode_as_default_reset, decode_as_default_change, NULL};
/* Placeholders for capture statistics */
proto_i2c_event = proto_register_protocol("I2C Events", "I2C Events", "i2c_event");
proto_i2c_data = proto_register_protocol("I2C Data", "I2C Data", "i2c_data");
proto_i2c = proto_register_protocol("Inter-Integrated Circuit", "I2C", "i2c");
proto_register_field_array(proto_i2c, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
subdissector_table = register_dissector_table("i2c.message", "I2C messages dissector", proto_i2c, FT_UINT32, BASE_DEC);
m = prefs_register_protocol(proto_i2c, NULL);
prefs_register_obsolete_preference(m, "type");
register_decode_as(&i2c_da);
}
void
proto_reg_handoff_i2c(void)
{
dissector_handle_t i2c_handle;
capture_dissector_handle_t i2c_cap_handle;
i2c_handle = create_dissector_handle(dissect_i2c, proto_i2c);
dissector_add_uint("wtap_encap", WTAP_ENCAP_I2C, i2c_handle);
i2c_cap_handle = create_capture_dissector_handle(capture_i2c, proto_i2c);
capture_dissector_add_uint("wtap_encap", WTAP_ENCAP_I2C, i2c_cap_handle);
}
/*
* 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:
*/
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