/* packet-mdshdr.c * Routines for dissection of Cisco MDS Switch Internal Header * Copyright 2001, Dinesh G Dutt * * $Id: packet-mdshdr.c,v 1.8 2003/10/30 02:06:12 guy Exp $ * * Ethereal - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * Copied from WHATEVER_FILE_YOU_USED (where "WHATEVER_FILE_YOU_USED" * is a dissector file; if you just copied this from README.developer, * don't bother with the "Copied from" - you don't even need to put * in a "Copied from" if you copied an existing dissector, especially * if the bulk of the code in the new dissector is your code) * * 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 #ifdef HAVE_SYS_TYPES_H # include #endif #ifdef HAVE_NETINET_IN_H # include #endif #include #ifdef NEED_SNPRINTF_H # include "snprintf.h" #endif #include #include #include #include "prefs.h" #define MDSHDR_VERSION_OFFSET 0 /* Mdshdr Control bits */ #define MDSHDR_CTL_IDXDIRECT 1 #define MDSHDR_CTL_IGNACLO 2 #define MDSHDR_CTL_DRP 4 /* OFFSETS OF FIELDS */ #define MDSHDR_VER_OFFSET 0 #define MDSHDR_SOF_OFFSET 1 #define MDSHDR_PKTLEN_OFFSET 2 #define MDSHDR_DIDX_OFFSET 5 #define MDSHDR_SIDX_OFFSET 6 #define MDSHDR_VSAN_OFFSET 13 /* Two size definitions are sufficient */ #define MDSHDR_SIZE_BYTE sizeof (gchar) #define MDSHDR_SIZE_INT16 sizeof (guint16) #define MDSHDR_SIZE_INT32 sizeof (guint32) /* Other miscellaneous defines; can't rely on sizeof structs */ #define MDSHDR_MAX_VERSION 0 #define MDSHDR_HEADER_SIZE 16 #define MDSHDR_TRAILER_SIZE 6 /* SOF Encodings */ #define MDSHDR_SOFc1 0x1 #define MDSHDR_SOFi1 0x2 #define MDSHDR_SOFn1 0x3 #define MDSHDR_SOFi2 0x4 #define MDSHDR_SOFn2 0x5 #define MDSHDR_SOFi3 0x6 #define MDSHDR_SOFn3 0x7 #define MDSHDR_SOFf 0x8 #define MDSHDR_SOFc4 0x9 #define MDSHDR_SOFi4 0xa #define MDSHDR_SOFn4 0xb /* EOF Encodings */ #define MDSHDR_EOFt 0x1 #define MDSHDR_EOFdt 0x2 #define MDSHDR_EOFa 0x4 #define MDSHDR_EOFn 0x3 #define MDSHDR_EOFdti 0x6 #define MDSHDR_EOFni 0x7 #define MDSHDR_EOFrt 0xa #define MDSHDR_EOFrti 0xe #define MDSHDR_EOF_UNKNOWN 0xb /* Initialize the protocol and registered fields */ static int proto_mdshdr = -1; static int hf_mdshdr_sof = -1; static int hf_mdshdr_pkt_len = -1; static int hf_mdshdr_dstidx = -1; static int hf_mdshdr_srcidx = -1; static int hf_mdshdr_vsan = -1; static int hf_mdshdr_eof = -1; static int hf_mdshdr_span = -1; static int hf_mdshdr_fccrc = -1; /* Initialize the subtree pointers */ static gint ett_mdshdr = -1; static gint ett_mdshdr_hdr = -1; static gint ett_mdshdr_trlr = -1; static dissector_handle_t data_handle, fc_dissector_handle; static gboolean decode_if_zero_etype = TRUE; static const value_string sof_vals[] = { {MDSHDR_SOFc1, "SOFc1"}, {MDSHDR_SOFi1, "SOFi1"}, {MDSHDR_SOFn1, "SOFn1"}, {MDSHDR_SOFi2, "SOFi2"}, {MDSHDR_SOFn2, "SOFn2"}, {MDSHDR_SOFi3, "SOFi3"}, {MDSHDR_SOFn3, "SOFn3"}, {MDSHDR_SOFc4, "SOFc4"}, {MDSHDR_SOFi4, "SOFi4"}, {MDSHDR_SOFn4, "SOFn4"}, {MDSHDR_SOFf, "SOFf"}, {0, NULL}, }; static const value_string eof_vals[] = { {MDSHDR_EOFt, "EOFt"}, {MDSHDR_EOFdt, "EOFdt"}, {MDSHDR_EOFa, "EOFa"}, {MDSHDR_EOFn, "EOFn"}, {MDSHDR_EOFdti, "EOFdti"}, {MDSHDR_EOFni, "EOFni"}, {MDSHDR_EOFrt, "EOFrt"}, {MDSHDR_EOFrti, "EOFrti"}, {MDSHDR_EOF_UNKNOWN, ""}, {0, NULL}, }; void proto_reg_handoff_mdshdr(void); /* Code to actually dissect the packets */ static void dissect_mdshdr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { /* Set up structures needed to add the protocol subtree and manage it */ proto_item *ti_main, *ti_hdr, *ti_trlr; proto_tree *mdshdr_tree_main, *mdshdr_tree_hdr, *mdshdr_tree_trlr; int offset = 0, pktlen; tvbuff_t *next_tvb; guint8 sof, eof; guint16 vsan; guint8 span_id; int trailer_start = 0; /* Make entries in Protocol column and Info column on summary display */ if (check_col(pinfo->cinfo, COL_PROTOCOL)) col_set_str(pinfo->cinfo, COL_PROTOCOL, "MDS Header"); if (check_col (pinfo->cinfo, COL_INFO)) col_clear (pinfo->cinfo, COL_INFO); sof = tvb_get_guint8 (tvb, offset+MDSHDR_SOF_OFFSET) & 0x0F; pktlen = tvb_get_ntohs (tvb, offset+MDSHDR_PKTLEN_OFFSET) & 0x1FFF; vsan = tvb_get_ntohs (tvb, offset+MDSHDR_VSAN_OFFSET) & 0x0FFF; span_id = (tvb_get_ntohs (tvb, offset+MDSHDR_VSAN_OFFSET) & 0xF000) >> 12; /* The Mdshdr trailer is at the end of the frame */ if (tvb_bytes_exist (tvb, 0, MDSHDR_HEADER_SIZE + pktlen)) { trailer_start = MDSHDR_HEADER_SIZE + pktlen - MDSHDR_TRAILER_SIZE; eof = tvb_get_guint8 (tvb, trailer_start); tvb_set_reported_length (tvb, MDSHDR_HEADER_SIZE+pktlen); } else { eof = MDSHDR_EOF_UNKNOWN; } pinfo->src_idx = (tvb_get_ntohs (tvb, MDSHDR_SIDX_OFFSET) & 0x3FF); pinfo->dst_idx = (tvb_get_ntohs (tvb, MDSHDR_DIDX_OFFSET) & 0xFFC) >> 6; pinfo->vsan = vsan; pinfo->sof_eof = 0; if ((sof == MDSHDR_SOFi3) || (sof == MDSHDR_SOFi2) || (sof == MDSHDR_SOFi1) || (sof == MDSHDR_SOFi4)) { pinfo->sof_eof = PINFO_SOF_FIRST_FRAME; } else if (sof == MDSHDR_SOFf) { pinfo->sof_eof = PINFO_SOF_SOFF; } if (eof != MDSHDR_EOFn) { pinfo->sof_eof |= PINFO_EOF_LAST_FRAME; } else if (eof != MDSHDR_EOFt) { pinfo->sof_eof |= PINFO_EOF_INVALID; } /* In the interest of speed, if "tree" is NULL, don't do any work not necessary to generate protocol tree items. */ if (tree) { /* create display subtree for the protocol */ ti_main = proto_tree_add_protocol_format (tree, proto_mdshdr, tvb, 0, MDSHDR_HEADER_SIZE+pktlen, "MDS Header(%s/%s)", val_to_str(sof, sof_vals, "Unknown(%u)"), val_to_str(eof, eof_vals, "Unknown(%u)")); mdshdr_tree_main = proto_item_add_subtree (ti_main, ett_mdshdr); /* Add Header part as subtree first */ ti_hdr = proto_tree_add_text (mdshdr_tree_main, tvb, MDSHDR_VER_OFFSET, MDSHDR_HEADER_SIZE, "MDS Header"); mdshdr_tree_hdr = proto_item_add_subtree (ti_hdr, ett_mdshdr_hdr); proto_tree_add_item_hidden (mdshdr_tree_hdr, hf_mdshdr_sof, tvb, MDSHDR_SOF_OFFSET, MDSHDR_SIZE_BYTE, 0); proto_tree_add_item (mdshdr_tree_hdr, hf_mdshdr_pkt_len, tvb, MDSHDR_PKTLEN_OFFSET, MDSHDR_SIZE_INT16, 0); proto_tree_add_item (mdshdr_tree_hdr, hf_mdshdr_dstidx, tvb, MDSHDR_DIDX_OFFSET, MDSHDR_SIZE_INT16, 0); proto_tree_add_item (mdshdr_tree_hdr, hf_mdshdr_srcidx, tvb, MDSHDR_SIDX_OFFSET, MDSHDR_SIZE_INT16, 0); proto_tree_add_item (mdshdr_tree_hdr, hf_mdshdr_vsan, tvb, MDSHDR_VSAN_OFFSET, MDSHDR_SIZE_INT16, 0); proto_tree_add_uint_hidden(mdshdr_tree_hdr, hf_mdshdr_span, tvb, MDSHDR_VSAN_OFFSET, MDSHDR_SIZE_BYTE, span_id); /* Add Mdshdr Trailer part */ if (tvb_bytes_exist (tvb, 0, MDSHDR_HEADER_SIZE+pktlen)) { ti_trlr = proto_tree_add_text (mdshdr_tree_main, tvb, trailer_start, MDSHDR_TRAILER_SIZE, "MDS Trailer"); mdshdr_tree_trlr = proto_item_add_subtree (ti_trlr, ett_mdshdr_trlr); proto_tree_add_item (mdshdr_tree_trlr, hf_mdshdr_eof, tvb, trailer_start, MDSHDR_SIZE_BYTE, 0); proto_tree_add_item (mdshdr_tree_trlr, hf_mdshdr_fccrc, tvb, trailer_start+2, MDSHDR_SIZE_INT32, 0); } } /* If this protocol has a sub-dissector call it here, see section 1.8 */ if (tvb_bytes_exist (tvb, 0, MDSHDR_HEADER_SIZE+pktlen)) { next_tvb = tvb_new_subset (tvb, MDSHDR_HEADER_SIZE, pktlen, pktlen); } else { next_tvb = tvb_new_subset (tvb, MDSHDR_HEADER_SIZE, -1, -1); } /* Call the Fibre Channel dissector */ if (fc_dissector_handle) { call_dissector (fc_dissector_handle, next_tvb, pinfo, tree); } else { call_dissector (data_handle, next_tvb, pinfo, tree); } } /* Register the protocol with Ethereal. This format is require because a script * is used to build the C function that calls all the protocol registration. */ void proto_register_mdshdr(void) { /* Setup list of header fields See Section 1.6.1 for details*/ static hf_register_info hf[] = { { &hf_mdshdr_sof, {"SOF", "mdshdr.sof", FT_UINT8, BASE_DEC, VALS(sof_vals), 0x0, "", HFILL}}, { &hf_mdshdr_pkt_len, {"Packet Len", "mdshdr.plen", FT_UINT16, BASE_DEC, NULL, 0x1FFF, "", HFILL}}, { &hf_mdshdr_dstidx, {"Dst Index", "mdshdr.dstidx", FT_UINT16, BASE_HEX, NULL, 0xFFC, "", HFILL}}, { &hf_mdshdr_srcidx, {"Src Index", "mdshdr.srcidx", FT_UINT16, BASE_HEX, NULL, 0x3FF, "", HFILL}}, { &hf_mdshdr_vsan, {"VSAN", "mdshdr.vsan", FT_UINT16, BASE_DEC, NULL, 0x0FFF, "", HFILL}}, { &hf_mdshdr_eof, {"EOF", "mdshdr.eof", FT_UINT8, BASE_DEC, VALS(eof_vals), 0x0, "", HFILL}}, { &hf_mdshdr_span, {"SPAN Frame", "mdshdr.span", FT_UINT8, BASE_DEC, NULL, 0x0, "", HFILL}}, { &hf_mdshdr_fccrc, {"CRC", "mdshdr.crc", FT_UINT32, BASE_HEX, NULL, 0x0, "", HFILL}}, }; /* Setup protocol subtree array */ static gint *ett[] = { &ett_mdshdr, &ett_mdshdr_hdr, &ett_mdshdr_trlr }; module_t *mdshdr_module; /* Register the protocol name and description */ proto_mdshdr = proto_register_protocol("MDS Header", "MDS Header", "mdshdr"); /* Required function calls to register the header fields and subtrees used */ proto_register_field_array(proto_mdshdr, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); mdshdr_module = prefs_register_protocol (proto_mdshdr, proto_reg_handoff_mdshdr); prefs_register_bool_preference (mdshdr_module, "decode_if_etype_zero", "Decode as MDS Header If Ethertype == 0", "A frame is considered for decoding as MDSHDR if either " "ethertype is 0xFCFC or zero. Turn this flag off if you " "you don't want ethertype zero to be decoded as MDSHDR. " "This might be useful to avoid problems with test frames.", &decode_if_zero_etype); } /* If this dissector uses sub-dissector registration add a registration routine. This format is required because a script is used to find these routines and create the code that calls these routines. */ void proto_reg_handoff_mdshdr(void) { static dissector_handle_t mdshdr_handle; static gboolean registered_for_zero_etype = FALSE; static gboolean mdshdr_prefs_initialized = FALSE; if (!mdshdr_prefs_initialized) { /* * This is the first time this has been called (i.e., * Ethereal/Tethereal is starting up), so create a handle for * the MDS Header dissector, register the dissector for * ethertype ETHERTYPE_FCFT, and fetch the data and Fibre * Channel handles. */ mdshdr_handle = create_dissector_handle (dissect_mdshdr, proto_mdshdr); dissector_add ("ethertype", ETHERTYPE_FCFT, mdshdr_handle); data_handle = find_dissector ("data"); fc_dissector_handle = find_dissector ("fc"); mdshdr_prefs_initialized = TRUE; } /* * Only register the dissector for ethertype 0 if the preference * is set to do so. */ if (decode_if_zero_etype) { /* * The preference to register for ethertype ETHERTYPE_UNK (0) * is set; if we're not registered for ethertype ETHERTYPE_UNK, * do so. */ if (!registered_for_zero_etype) { dissector_add ("ethertype", ETHERTYPE_UNK, mdshdr_handle); registered_for_zero_etype = TRUE; } } else { /* * The preference to register for ethertype ETHERTYPE_UNK (0) * is not set; if we're registered for ethertype ETHERTYPE_UNK, * undo that registration. */ if (registered_for_zero_etype) { dissector_delete ("ethertype", ETHERTYPE_UNK, mdshdr_handle); registered_for_zero_etype = FALSE; } } }