/* packet-arcnet.c * Routines for arcnet dissection * Copyright 2001-2002, Peter Fales * * $Id: packet-arcnet.c,v 1.11 2003/12/19 19:09:49 guy Exp $ * * Ethereal - 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 #include #include "packet-arcnet.h" #include "arcnet_pids.h" #include "packet-ip.h" /* Initialize the protocol and registered fields */ static int proto_arcnet = -1; static int hf_arcnet_src = -1; static int hf_arcnet_dst = -1; static int hf_arcnet_offset = -1; static int hf_arcnet_protID = -1; static int hf_arcnet_exception_flag = -1; static int hf_arcnet_split_flag = -1; static int hf_arcnet_sequence = -1; /* Initialize the subtree pointers */ static gint ett_arcnet = -1; static dissector_table_t arcnet_dissector_table; static dissector_handle_t data_handle; void capture_arcnet (const guchar *pd, int len, packet_counts *ld, gboolean has_offset, gboolean has_exception) { int offset = has_offset ? 4 : 2; if (!BYTES_ARE_IN_FRAME(offset, len, 1)) { ld->other++; return; } switch (pd[offset]) { case ARCNET_PROTO_IP_1051: /* No fragmentation stuff in the header */ capture_ip(pd, offset + 1, len, ld); break; case ARCNET_PROTO_IP_1201: /* * There's fragmentation stuff in the header. * * XXX - on at least some versions of NetBSD, it appears that we * might we get ARCNET frames, not reassembled packets; we should * perhaps bump "ld->other" for all but the first frame of a packet. * * XXX - but on FreeBSD it appears that we get reassembled packets * on input (but apparently we get frames on output - or maybe * we get the packet *and* all its frames!); how to tell the * difference? It looks from the FreeBSD reassembly code as if * the reassembled packet arrives with the header for the first * frame. It also looks as if, on output, we first get the * full packet, with a header containing none of the fragmentation * stuff, and then get the frames. * * On Linux, we get only reassembled packets, and the exception * frame stuff is hidden - there's a split flag and sequence * number, but it appears that it will never have the exception * frame stuff. * * XXX - what about OpenBSD? And, for that matter, what about * Windows? (I suspect Windows supplies reassembled frames, * as WinPcap, like PF_PACKET sockets, taps into the networking * stack just as other protocols do.) */ offset++; if (!BYTES_ARE_IN_FRAME(offset, len, 1)) { ld->other++; return; } if (has_exception && pd[offset] == 0xff) { /* This is an exception packet. The flag value there is the "this is an exception flag" packet; the next two bytes after it are padding, and another copy of the packet type appears after the padding. */ offset += 4; } capture_ip(pd, offset + 3, len, ld); break; case ARCNET_PROTO_ARP_1051: case ARCNET_PROTO_ARP_1201: /* * XXX - do we have to worry about fragmentation for ARP? */ ld->arp++; break; case ARCNET_PROTO_IPX: ld->ipx++; break; default: ld->other++; break; } } static void dissect_arcnet_common (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, gboolean has_offset, gboolean has_exception) { int offset = 0; guint8 dst, src, protID, split_flag; tvbuff_t *next_tvb; proto_item *ti = NULL; proto_tree *arcnet_tree = NULL; if (check_col (pinfo->cinfo, COL_PROTOCOL)) col_set_str (pinfo->cinfo, COL_PROTOCOL, "ARCNET"); if (check_col (pinfo->cinfo, COL_INFO)) col_set_str (pinfo->cinfo, COL_INFO, "ARCNET"); src = tvb_get_guint8 (tvb, 0); dst = tvb_get_guint8 (tvb, 1); SET_ADDRESS(&pinfo->dl_src, AT_ARCNET, 1, tvb_get_ptr(tvb, 0, 1)); SET_ADDRESS(&pinfo->src, AT_ARCNET, 1, tvb_get_ptr(tvb, 0, 1)); SET_ADDRESS(&pinfo->dl_dst, AT_ARCNET, 1, tvb_get_ptr(tvb, 1, 1)); SET_ADDRESS(&pinfo->dst, AT_ARCNET, 1, tvb_get_ptr(tvb, 1, 1)); if (tree) { ti = proto_tree_add_item (tree, proto_arcnet, tvb, 0, -1, FALSE); arcnet_tree = proto_item_add_subtree (ti, ett_arcnet); proto_tree_add_uint (tree, hf_arcnet_src, tvb, offset, 1, src); } offset++; if (tree) proto_tree_add_uint (tree, hf_arcnet_dst, tvb, offset, 1, dst); offset++; if (has_offset) { if (tree) proto_tree_add_item (tree, hf_arcnet_offset, tvb, offset, 2, FALSE); offset += 2; } protID = tvb_get_guint8 (tvb, offset); if (tree) proto_tree_add_uint (tree, hf_arcnet_protID, tvb, offset, 1, protID); offset++; switch (protID) { case ARCNET_PROTO_IP_1051: case ARCNET_PROTO_ARP_1051: case ARCNET_PROTO_DIAGNOSE: case ARCNET_PROTO_BACNET: /* XXX - no fragmentation? */ /* No fragmentation stuff in the header */ break; default: /* * Show the fragmentation stuff - flag and sequence ID. * * XXX - on at least some versions of NetBSD, it appears that * we might get ARCNET frames, not reassembled packets; if so, * we should reassemble them. * * XXX - but on FreeBSD it appears that we get reassembled packets * on input (but apparently we get frames on output - or maybe * we get the packet *and* all its frames!); how to tell the * difference? It looks from the FreeBSD reassembly code as if * the reassembled packet arrives with the header for the first * frame. It also looks as if, on output, we first get the * full packet, with a header containing none of the fragmentation * stuff, and then get the frames. * * On Linux, we get only reassembled packets, and the exception * frame stuff is hidden - there's a split flag and sequence * number, but it appears that it will never have the exception * frame stuff. * * XXX - what about OpenBSD? And, for that matter, what about * Windows? (I suspect Windows supplies reassembled frames, * as WinPcap, like PF_PACKET sockets, taps into the networking * stack just as other protocols do.) */ split_flag = tvb_get_guint8 (tvb, offset); if (has_exception && split_flag == 0xff) { /* This is an exception packet. The flag value there is the "this is an exception flag" packet; the next two bytes after it are padding. */ if (tree) { proto_tree_add_uint (tree, hf_arcnet_exception_flag, tvb, offset, 1, split_flag); } offset++; if (tree) proto_tree_add_text (tree, tvb, offset, 2, "Padding"); offset += 2; /* Another copy of the packet type appears after the padding. */ if (tree) proto_tree_add_item (tree, hf_arcnet_protID, tvb, offset, 1, FALSE); offset++; /* And after that comes the real split flag. */ split_flag = tvb_get_guint8 (tvb, offset); } if (tree) { proto_tree_add_uint (tree, hf_arcnet_split_flag, tvb, offset, 1, split_flag); } offset++; if (tree) proto_tree_add_item (tree, hf_arcnet_sequence, tvb, offset, 2, FALSE); offset += 2; break; } /* Set the length of the ARCNET header protocol tree item. */ if (tree) proto_item_set_len(ti, offset); next_tvb = tvb_new_subset (tvb, offset, -1, -1); if (!dissector_try_port (arcnet_dissector_table, protID, next_tvb, pinfo, tree)) { if (check_col (pinfo->cinfo, COL_PROTOCOL)) { col_add_fstr (pinfo->cinfo, COL_PROTOCOL, "0x%04x", protID); } call_dissector (data_handle, next_tvb, pinfo, tree); } } /* * BSD-style ARCNET headers - they don't have the offset field from the * ARCNET hardware packet, but we might get an exception frame header. */ static void dissect_arcnet (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree) { dissect_arcnet_common (tvb, pinfo, tree, FALSE, TRUE); } /* * Linux-style ARCNET headers - they *do* have the offset field from the * ARCNET hardware packet, but we should never see an exception frame * header. */ static void dissect_arcnet_linux (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree) { dissect_arcnet_common (tvb, pinfo, tree, TRUE, FALSE); } static const value_string arcnet_prot_id_vals[] = { {ARCNET_PROTO_IP_1051, "RFC 1051 IP"}, {ARCNET_PROTO_ARP_1051, "RFC 1051 ARP"}, {ARCNET_PROTO_IP_1201, "RFC 1201 IP"}, {ARCNET_PROTO_ARP_1201, "RFC 1201 ARP"}, {ARCNET_PROTO_RARP_1201, "RFC 1201 RARP"}, {ARCNET_PROTO_IPX, "IPX"}, {ARCNET_PROTO_NOVELL_EC, "Novell of some sort"}, {ARCNET_PROTO_IPv6, "IPv6"}, {ARCNET_PROTO_ETHERNET, "Encapsulated Ethernet"}, {ARCNET_PROTO_DATAPOINT_BOOT, "Datapoint boot"}, {ARCNET_PROTO_DATAPOINT_MOUNT, "Datapoint mount"}, {ARCNET_PROTO_POWERLAN_BEACON, "PowerLAN beacon"}, {ARCNET_PROTO_POWERLAN_BEACON2, "PowerLAN beacon2"}, {ARCNET_PROTO_APPLETALK, "Appletalk"}, {ARCNET_PROTO_BANYAN, "Banyan VINES"}, {ARCNET_PROTO_DIAGNOSE, "Diagnose"}, {ARCNET_PROTO_BACNET, "BACnet"}, {0, NULL} }; void proto_register_arcnet (void) { /* Setup list of header fields See Section 1.6.1 for details*/ static hf_register_info hf[] = { {&hf_arcnet_src, {"Source", "arcnet.src", FT_UINT8, BASE_HEX, NULL, 0, "Source ID", HFILL} }, {&hf_arcnet_dst, {"Dest", "arcnet.dst", FT_UINT8, BASE_HEX, NULL, 0, "Dest ID", HFILL} }, {&hf_arcnet_offset, {"Offset", "arcnet.offset", FT_BYTES, BASE_NONE, NULL, 0, "Offset", HFILL} }, {&hf_arcnet_protID, {"Protocol ID", "arcnet.protID", FT_UINT8, BASE_HEX, VALS(arcnet_prot_id_vals), 0, "Proto type", HFILL} }, {&hf_arcnet_split_flag, {"Split Flag", "arcnet.split_flag", FT_UINT8, BASE_DEC, NULL, 0, "Split flag", HFILL} }, {&hf_arcnet_exception_flag, {"Exception Flag", "arcnet.exception_flag", FT_UINT8, BASE_HEX, NULL, 0, "Exception flag", HFILL} }, {&hf_arcnet_sequence, {"Sequence", "arcnet.sequence", FT_UINT16, BASE_DEC, NULL, 0, "Sequence number", HFILL} }, }; /* Setup protocol subtree array */ static gint *ett[] = { &ett_arcnet, }; arcnet_dissector_table = register_dissector_table ("arcnet.protocol_id", "ARCNET Protocol ID", FT_UINT8, BASE_HEX); /* Register the protocol name and description */ proto_arcnet = proto_register_protocol ("ARCNET", "ARCNET", "arcnet"); /* Required function calls to register the header fields and subtrees used */ proto_register_field_array (proto_arcnet, hf, array_length (hf)); proto_register_subtree_array (ett, array_length (ett)); } void proto_reg_handoff_arcnet (void) { dissector_handle_t arcnet_handle, arcnet_linux_handle; arcnet_handle = create_dissector_handle (dissect_arcnet, proto_arcnet); dissector_add ("wtap_encap", WTAP_ENCAP_ARCNET, arcnet_handle); arcnet_linux_handle = create_dissector_handle (dissect_arcnet_linux, proto_arcnet); dissector_add ("wtap_encap", WTAP_ENCAP_ARCNET_LINUX, arcnet_linux_handle); data_handle = find_dissector ("data"); }