forked from osmocom/wireshark
![Guy Harris](/assets/img/avatar_default.png)
build_label_func is a pointer type, pointing to a function that can be used to generate a label for a "Decode As" entry. There's no need to have pointers to those pointers; have register_decode_as_next_proto() take a build_label_func, not a build_label_func *, as its last argument, assign that value rather than dereferencing it, get rid of unnecessary casts, and fix the comment in epan/decode_as.h for that argument. Change-Id: Idc3cf18204c543a2191b122c8129b362562c0ecd Reviewed-on: https://code.wireshark.org/review/25773 Reviewed-by: Guy Harris <guy@alum.mit.edu>
263 lines
8.5 KiB
C
263 lines
8.5 KiB
C
/* packet-i2c.c
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* Routines for I2C captures (using libpcap extensions)
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*
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* Pigeon Point Systems <www.pigeonpoint.com>
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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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* SPDX-License-Identifier: GPL-2.0-or-later
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*/
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#include "config.h"
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#include <epan/packet.h>
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#include <epan/capture_dissectors.h>
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#include <epan/prefs.h>
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#include <epan/decode_as.h>
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#include <wiretap/wtap.h>
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void proto_register_i2c(void);
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void proto_reg_handoff_i2c(void);
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static int proto_i2c = -1;
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static int proto_i2c_event = -1;
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static int proto_i2c_data = -1;
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static int hf_i2c_bus = -1;
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static int hf_i2c_event = -1;
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static int hf_i2c_flags = -1;
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static int hf_i2c_addr = -1;
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static gint ett_i2c = -1;
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static dissector_table_t subdissector_table;
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/* I2C packet flags. */
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#define I2C_FLAG_RD 0x00000001
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#define I2C_FLAG_TEN 0x00000010
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#define I2C_FLAG_REV_DIR_ADDR 0x00002000
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#define I2C_FLAG_NOSTART 0x00004000
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/* I2C events. */
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#define I2C_EVENT_PROM_ON (1 << 0) /* Promiscuous mode: on */
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#define I2C_EVENT_PROM_OFF (1 << 1) /* Promiscuous mode: off */
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#define I2C_EVENT_ONLINE_ON (1 << 2) /* Online state: on */
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#define I2C_EVENT_ONLINE_OFF (1 << 3) /* Online state: off */
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#define I2C_EVENT_ATTACHED_ON (1 << 4) /* Attached state: on */
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#define I2C_EVENT_ATTACHED_OFF (1 << 5) /* Attached state: off */
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#define I2C_EVENT_PROM_OVFL_ON (1 << 6) /* Prom. queue overflow: on */
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#define I2C_EVENT_PROM_OVFL_OFF (1 << 7) /* Prom. queue overflow: off */
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#define I2C_EVENT_OVFL_ON (1 << 8) /* Queue overflow: on */
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#define I2C_EVENT_OVFL_OFF (1 << 9) /* Queue overflow: off */
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/* I2C errors. */
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#define I2C_EVENT_ERR_DATA_LO (1 << 16) /* Unable to drive data LO */
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#define I2C_EVENT_ERR_DATA_HI (1 << 17) /* Unable to drive data HI */
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#define I2C_EVENT_ERR_CLOCK_LO (1 << 18) /* Unable to drive clock LO */
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#define I2C_EVENT_ERR_CLOCK_HI (1 << 19) /* Unable to drive clock HI */
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#define I2C_EVENT_ERR_CLOCK_TO (1 << 20) /* Clock low timeout */
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#define I2C_EVENT_ERR_PHYS (1 << 21) /* The I2C bus controller
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has been physically
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disconnected from the bus */
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#define I2C_EVENT_ERR_FAIL (1 << 22) /* Undiagnosed failure */
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static void i2c_prompt(packet_info *pinfo _U_, gchar* result)
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{
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g_snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "Interpret I2C messages as");
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}
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static gboolean
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capture_i2c(const guchar *pd _U_, int offset _U_, int len _U_, capture_packet_info_t *cpinfo, const union wtap_pseudo_header *pseudo_header)
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{
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if (pseudo_header->i2c.is_event) {
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capture_dissector_increment_count(cpinfo, proto_i2c_event);
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} else {
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capture_dissector_increment_count(cpinfo, proto_i2c_data);
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}
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return TRUE;
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}
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static const char *
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i2c_get_event_desc(guint32 event)
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{
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const char *desc;
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switch (event & 0x0000ffff) {
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case I2C_EVENT_PROM_ON:
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desc = "Promiscuous mode is enabled";
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break;
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case I2C_EVENT_PROM_OFF:
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desc = "Promiscuous mode is disabled";
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break;
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case I2C_EVENT_ONLINE_ON:
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desc = "The I2C controller is operational";
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break;
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case I2C_EVENT_ONLINE_OFF:
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desc = "The I2C controller is non-operational";
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break;
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case I2C_EVENT_ATTACHED_ON:
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desc = "The I2C controller is attached to an I2C bus";
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break;
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case I2C_EVENT_ATTACHED_OFF:
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desc = "The I2C controller is detached from an I2C bus";
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if (event & I2C_EVENT_ERR_DATA_LO) {
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desc = "The I2C controller is detached from an I2C bus: "
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"unable to drive data LO";
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} else if (event & I2C_EVENT_ERR_DATA_HI) {
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desc = "The I2C controller is detached from an I2C bus: "
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"unable to drive data HI";
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} else if (event & I2C_EVENT_ERR_CLOCK_LO) {
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desc = "The I2C controller is detached from an I2C bus: "
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"unable to drive clock LO";
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} else if (event & I2C_EVENT_ERR_CLOCK_HI) {
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desc = "The I2C controller is detached from an I2C bus: "
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"unable to drive clock HI";
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} else if (event & I2C_EVENT_ERR_CLOCK_TO) {
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desc = "The I2C controller is detached from an I2C bus: "
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"clock low timeout";
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} else if (event & I2C_EVENT_ERR_PHYS) {
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desc = "The I2C controller is detached from an I2C bus: "
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"the I2C bus controller has been physically "
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"disconnected from the bus";
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} else if (event & I2C_EVENT_ERR_FAIL) {
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desc = "The I2C controller is detached from an I2C bus: "
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"undiagnosed failure";
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}
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break;
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case I2C_EVENT_PROM_OVFL_ON:
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desc = "The incoming promiscuous data buffer has been overrun; "
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"some data is lost";
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break;
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case I2C_EVENT_PROM_OVFL_OFF:
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desc = "The incoming promiscuous data buffer is available";
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break;
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case I2C_EVENT_OVFL_ON:
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desc = "The incoming I2C data buffer has been overrun; "
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"some data is lost";
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break;
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case I2C_EVENT_OVFL_OFF:
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desc = "The incoming I2C data buffer is available";
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break;
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default:
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desc = "<unknown state event>";
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break;
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}
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return desc;
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}
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static int
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dissect_i2c(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
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{
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proto_item *ti;
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proto_tree *i2c_tree;
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guint8 is_event;
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guint8 bus, addr;
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guint32 flags;
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flags = pinfo->pseudo_header->i2c.flags;
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bus = pinfo->pseudo_header->i2c.bus;
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col_add_fstr(pinfo->cinfo, COL_DEF_SRC, "I2C-%d", bus);
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is_event = pinfo->pseudo_header->i2c.is_event;
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if (is_event) {
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addr = 0;
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "I2C Event");
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col_add_fstr(pinfo->cinfo, COL_DEF_DST, "----");
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col_add_fstr(pinfo->cinfo, COL_INFO, "%s",
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i2c_get_event_desc(flags));
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} else {
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/* Report 7-bit hardware address */
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addr = tvb_get_guint8(tvb, 0) >> 1;
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col_add_fstr(pinfo->cinfo, COL_PROTOCOL, "I2C %s",
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(flags & I2C_FLAG_RD) ? "Read" : "Write");
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col_add_fstr(pinfo->cinfo, COL_DEF_DST, "0x%02x", addr);
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col_add_fstr(pinfo->cinfo, COL_INFO, "I2C %s, %d bytes",
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(flags & I2C_FLAG_RD) ? "Read" : "Write", tvb_captured_length(tvb));
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}
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pinfo->ptype = PT_I2C;
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ti = proto_tree_add_protocol_format(tree, proto_i2c, tvb, 0, -1,
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"Inter-Integrated Circuit (%s)",
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is_event ? "Event" : "Data");
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i2c_tree = proto_item_add_subtree(ti, ett_i2c);
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proto_tree_add_uint_format(i2c_tree, hf_i2c_bus, tvb, 0, 0, bus,
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"Bus: I2C-%d", bus);
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if (is_event) {
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proto_tree_add_uint_format_value(i2c_tree, hf_i2c_event, tvb, 0, 0,
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flags, "%s (0x%08x)",
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i2c_get_event_desc(flags), flags);
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} else {
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proto_tree_add_uint_format_value(i2c_tree, hf_i2c_addr, tvb, 0, 1,
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addr, "0x%02x%s", addr, addr ? "" : " (General Call)");
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proto_tree_add_uint(i2c_tree, hf_i2c_flags, tvb, 0, 0, flags);
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if (!dissector_try_payload(subdissector_table, tvb, pinfo, tree))
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{
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call_data_dissector(tvb, pinfo, tree);
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}
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}
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return tvb_captured_length(tvb);
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}
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void
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proto_register_i2c(void)
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{
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static hf_register_info hf[] = {
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{ &hf_i2c_bus, { "Bus ID", "i2c.bus", FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL }},
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{ &hf_i2c_addr, { "Target address", "i2c.addr", FT_UINT8, BASE_HEX, NULL, 0, NULL, HFILL }},
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{ &hf_i2c_event, { "Event", "i2c.event", FT_UINT32, BASE_HEX, NULL, 0, NULL, HFILL }},
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{ &hf_i2c_flags, { "Flags", "i2c.flags", FT_UINT32, BASE_HEX, NULL, 0, NULL, HFILL }},
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};
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static gint *ett[] = {
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&ett_i2c
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};
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module_t *m;
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proto_i2c = proto_register_protocol("Inter-Integrated Circuit", "I2C", "i2c");
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proto_register_field_array(proto_i2c, hf, array_length(hf));
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proto_register_subtree_array(ett, array_length(ett));
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/* Placeholders for capture statistics */
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proto_i2c_event = proto_register_protocol_in_name_only("I2C Events", "I2C Events", "i2c_event", proto_i2c, FT_PROTOCOL);
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proto_i2c_data = proto_register_protocol_in_name_only("I2C Data", "I2C Data", "i2c_data", proto_i2c, FT_PROTOCOL);
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m = prefs_register_protocol(proto_i2c, NULL);
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prefs_register_obsolete_preference(m, "type");
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subdissector_table = register_decode_as_next_proto(proto_i2c, "I2C Message", "i2c.message", "I2C messages dissector", i2c_prompt);
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}
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void
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proto_reg_handoff_i2c(void)
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{
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dissector_handle_t i2c_handle;
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capture_dissector_handle_t i2c_cap_handle;
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i2c_handle = create_dissector_handle(dissect_i2c, proto_i2c);
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dissector_add_uint("wtap_encap", WTAP_ENCAP_I2C, i2c_handle);
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i2c_cap_handle = create_capture_dissector_handle(capture_i2c, proto_i2c);
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capture_dissector_add_uint("wtap_encap", WTAP_ENCAP_I2C, i2c_cap_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: 8
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* tab-width: 8
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* indent-tabs-mode: t
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* End:
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*
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* vi: set shiftwidth=8 tabstop=8 noexpandtab:
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* :indentSize=8:tabSize=8:noTabs=false:
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*/
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