/* packet-socketcan.c * Routines for disassembly of packets from SocketCAN * Felix Obenhuber * * $Id$ * * Wireshark - Network traffic analyzer * By Gerald Combs * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #include #include #include #include "packet-sll.h" /* controller area network (CAN) kernel definitions * These masks are usually defined within but are not * available on non-Linux platforms; that's the reason for the * redefinitions below * * special address description flags for the CAN_ID */ #define CAN_EFF_FLAG 0x80000000U /* EFF/SFF is set in the MSB */ #define CAN_RTR_FLAG 0x40000000U /* remote transmission request */ #define CAN_ERR_FLAG 0x20000000U /* error frame */ #define CAN_EFF_MASK 0x1FFFFFFFU /* extended frame format (EFF) */ static int hf_can_len = -1; static int hf_can_ident = -1; static int hf_can_extflag = -1; static int hf_can_rtrflag = -1; static int hf_can_errflag = -1; static gint ett_can = -1; static int proto_can = -1; static dissector_handle_t data_handle; static dissector_handle_t canopen_handle; #define LINUX_CAN_STD 0 #define LINUX_CAN_EXT 1 #define LINUX_CAN_RTR 2 #define LINUX_CAN_ERR 3 #define CAN_LEN_OFFSET 4 #define CAN_DATA_OFFSET 8 typedef enum { CAN_DATA_DISSECTOR = 1, CAN_CANOPEN_DISSECTOR = 2 } Dissector_Option; static enum_val_t can_high_level_protocol_dissector_options[] = { { "raw", "Raw data (no further dissection)", CAN_DATA_DISSECTOR }, { "CANopen", "CANopen protocol", CAN_CANOPEN_DISSECTOR }, { NULL, NULL, 0 } }; static guint can_high_level_protocol_dissector = CAN_DATA_DISSECTOR; static const value_string frame_type_vals[] = { { LINUX_CAN_STD, "STD" }, { LINUX_CAN_EXT, "XTD" }, { LINUX_CAN_RTR, "RTR" }, { LINUX_CAN_ERR, "ERR" }, { 0, NULL } }; static void dissect_socketcan(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { proto_tree *can_tree; proto_item *ti; guint8 frame_type; gint frame_len; guint32 id; col_set_str(pinfo->cinfo, COL_PROTOCOL, "CAN"); col_clear(pinfo->cinfo,COL_INFO); frame_len = tvb_get_guint8( tvb, CAN_LEN_OFFSET); id = tvb_get_ntohl(tvb, 0); if (id & CAN_RTR_FLAG) { frame_type = LINUX_CAN_RTR; } else if (id & CAN_ERR_FLAG) { frame_type = LINUX_CAN_ERR; } else if (id & CAN_EFF_FLAG) { frame_type = LINUX_CAN_EXT; } else { frame_type = LINUX_CAN_STD; } id &= CAN_EFF_MASK; col_add_fstr(pinfo->cinfo, COL_INFO, "%s: 0x%08x", val_to_str(frame_type, frame_type_vals, "Unknown (0x%02x)"), id); col_append_fstr(pinfo->cinfo, COL_INFO, " %s", tvb_bytes_to_str_punct(tvb, CAN_DATA_OFFSET, frame_len, ' ')); ti = proto_tree_add_item(tree, proto_can, tvb, 0, -1, ENC_NA); can_tree = proto_item_add_subtree(ti, ett_can); proto_tree_add_item(can_tree, hf_can_ident, tvb, 0, 4, ENC_BIG_ENDIAN); proto_tree_add_item(can_tree, hf_can_extflag, tvb, 0, 4, ENC_BIG_ENDIAN); proto_tree_add_item(can_tree, hf_can_rtrflag, tvb, 0, 4, ENC_BIG_ENDIAN); proto_tree_add_item(can_tree, hf_can_errflag, tvb, 0, 4, ENC_BIG_ENDIAN); proto_tree_add_item(can_tree, hf_can_len, tvb, CAN_LEN_OFFSET, 1, ENC_BIG_ENDIAN); switch (can_high_level_protocol_dissector) { case CAN_DATA_DISSECTOR: call_dissector(data_handle, tvb_new_subset(tvb, CAN_DATA_OFFSET, frame_len, frame_len), pinfo, tree); break; case CAN_CANOPEN_DISSECTOR: /* XXX: The canopen dissector *redissects in a different manner* */ /* the same header bytes dissected above. */ /* What's the right way to handle SocketCan dissection ? */ call_dissector(canopen_handle, tvb, pinfo, tree); break; } } void proto_register_socketcan(void) { static hf_register_info hf[] = { { &hf_can_ident, { "Identifier", "can.id", FT_UINT32, BASE_HEX, NULL, CAN_EFF_MASK, NULL, HFILL } }, { &hf_can_extflag, { "Extended Flag", "can.flags.xtd", FT_BOOLEAN, 32, NULL, CAN_EFF_FLAG, NULL, HFILL } }, { &hf_can_rtrflag, { "Remote Transmission Request Flag", "can.flags.rtr", FT_BOOLEAN, 32, NULL, CAN_RTR_FLAG, NULL, HFILL } }, { &hf_can_errflag, { "Error Flag", "can.flags.err", FT_BOOLEAN, 32, NULL, CAN_ERR_FLAG, NULL, HFILL } }, { &hf_can_len, { "Frame-Length", "can.len", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL } } }; /* Setup protocol subtree array */ static gint *ett[] = { &ett_can }; module_t *can_module; proto_can = proto_register_protocol( "Controller Area Network", /* name */ "CAN", /* short name */ "can" /* abbrev */ ); proto_register_field_array(proto_can, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); can_module = prefs_register_protocol(proto_can, NULL); prefs_register_enum_preference( can_module, "protocol", "Next level protocol", "Next level protocol like CANopen etc.", (gint *)&can_high_level_protocol_dissector, can_high_level_protocol_dissector_options, FALSE ); } void proto_reg_handoff_socketcan(void) { dissector_handle_t can_handle; can_handle = create_dissector_handle(dissect_socketcan, proto_can); dissector_add_uint("wtap_encap", WTAP_ENCAP_SOCKETCAN, can_handle); dissector_add_uint("sll.ltype", LINUX_SLL_P_CAN, can_handle); canopen_handle = find_dissector("canopen"); data_handle = find_dissector("data"); }