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wireshark/epan/dissectors/packet-i2c.c
Michael Mann 1e60d63c8c Create call_data_dissector() to call data dissector. 
This saves many dissectors the need to find the data dissector and store a handle to it.

There were also some that were finding it, but not using it.
For others this was the only reason for their handoff function, so it could be eliminated.

Change-Id: I5d3f951ee1daa3d30c060d21bd12bbc881a8027b
Reviewed-on: https://code.wireshark.org/review/14530
Petri-Dish: Michael Mann <mmann78@netscape.net>
Reviewed-by: Michael Mann <mmann78@netscape.net>
2016-03-20 17:38:03 +00:00

288 lines
9.6 KiB
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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, DISSECTOR_TABLE_NOT_ALLOW_DUPLICATE);
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;
i2c_handle = create_dissector_handle(dissect_i2c, proto_i2c);
dissector_add_uint("wtap_encap", WTAP_ENCAP_I2C, i2c_handle);
register_capture_dissector("wtap_encap", WTAP_ENCAP_I2C, capture_i2c, proto_i2c);
}
/*
* 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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