/* packet-isis-clv.c * Common CLV decode routines. * * Stuart Stanley * * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "config.h" #include #include #include "packet-isis-clv.h" #include /* * Name: isis_dissect_area_address_clv() * * Description: * Take an area address CLV and display it pieces. An area address * CLV is n, x byte hex strings. * * Input: * tvbuff_t * : tvbuffer for packet data * proto_tree * : protocol display tree to fill out. May be NULL * int : offset into packet data where we are. * int : length of clv we are decoding * * Output: * void, but we will add to proto tree if !NULL. */ void isis_dissect_area_address_clv(proto_tree *tree, packet_info* pinfo, tvbuff_t *tvb, expert_field* expert, int hf_area, int offset, int length) { int arealen,area_idx; while ( length > 0 ) { arealen = tvb_get_guint8(tvb, offset); length--; if (length<=0) { proto_tree_add_expert_format(tree, pinfo, expert, tvb, offset, -1, "short address (no length for payload)"); return; } if ( arealen > length) { proto_tree_add_expert_format(tree, pinfo, expert, tvb, offset, -1, "short address, packet says %d, we have %d left", arealen, length ); return; } if ( tree ) { proto_item *ti; ti = proto_tree_add_bytes_format( tree, hf_area, tvb, offset, arealen + 1, NULL, "Area address (%d): ", arealen ); /* * Lets turn the area address into "standard" * xx.xxxx.xxxx.xxxx.xxxx.xxxx.xxxx format string. * this is a private routine as the print_nsap_net in * epan/osi_utils.c is incomplete and we need only * a subset - actually some nice placing of dots .... */ for (area_idx = 0; area_idx < arealen; area_idx++) { proto_item_append_text(ti, "%02x", tvb_get_guint8(tvb, offset+area_idx+1)); if (((area_idx & 1) == 0) && (area_idx + 1 < arealen)) { proto_item_append_text(ti, "."); } } } offset += arealen + 1; length -= arealen; /* length already adjusted for len fld*/ } } /* * Name: isis_dissect_instance_identifier_clv() * * * Input: * tvbuff_t * : tvbuffer for packet data * proto_tree * : protocol display tree to fill out. May be NULL * int : offset into packet data where we are. * int : length of clv we are decoding * * Output: * void, but we will add to proto tree if !NULL. */ void isis_dissect_instance_identifier_clv(proto_tree *tree, packet_info* pinfo, tvbuff_t *tvb, expert_field* expert, int hf_iid, int hf_supported_itid, int offset, int length) { length--; if (length<=0) { proto_tree_add_expert_format(tree, pinfo, expert, tvb, offset, -1, "short address (no length for payload)"); return; } proto_tree_add_item(tree, hf_iid, tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2; length -= 2; while ( length > 0 ) { proto_tree_add_item(tree, hf_supported_itid, tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2; length -= 2; } } /* * Name: isis_dissect_authentication_clv() * * Description: * Take apart the CLV that hold authentication information. This * is currently 1 octet auth type. * the two defined authentication types * are 1 for a clear text password and * 54 for a HMAC-MD5 digest * * Input: * tvbuff_t * : tvbuffer for packet data * proto_tree * : protocol display tree to fill out. May be NULL * int : offset into packet data where we are. * int : length of clv we are decoding * * Output: * void, but we will add to proto tree if !NULL. */ void isis_dissect_authentication_clv(proto_tree *tree, packet_info* pinfo, tvbuff_t *tvb, int hf_auth_bytes, expert_field* auth_expert, int offset, int length) { guchar pw_type; int auth_unsupported; if ( length <= 0 ) { return; } pw_type = tvb_get_guint8(tvb, offset); offset += 1; length--; auth_unsupported = FALSE; switch (pw_type) { case 1: if ( length > 0 ) { proto_tree_add_bytes_format( tree, hf_auth_bytes, tvb, offset, length, NULL, "clear text (1), password (length %d) = %s", length, tvb_format_text(tvb, offset, length)); } else { proto_tree_add_bytes_format( tree, hf_auth_bytes, tvb, offset, length, NULL, "clear text (1), no clear-text password found!!!"); } break; case 54: if ( length == 16 ) { proto_tree_add_bytes_format( tree, hf_auth_bytes, tvb, offset, length, NULL, "hmac-md5 (54), password (length %d) = %s", length, tvb_bytes_to_str(wmem_packet_scope(), tvb, offset, length)); } else { proto_tree_add_bytes_format( tree, hf_auth_bytes, tvb, offset, length, NULL, "hmac-md5 (54), illegal hmac-md5 digest format (must be 16 bytes)"); } break; default: proto_tree_add_bytes_format( tree, hf_auth_bytes, tvb, offset, length, NULL, "type 0x%02x (0x%02x)", pw_type, length); auth_unsupported=TRUE; break; } if ( auth_unsupported ) { proto_tree_add_expert(tree, pinfo, auth_expert, tvb, offset, -1); } } /* * Name: isis_dissect_hostname_clv() * * Description: * dump the hostname information found in TLV 137 * pls note that the hostname is not null terminated * * Input: * tvbuff_t * : tvbuffer for packet data * proto_tree * : protocol display tree to fill out. May be NULL * int : offset into packet data where we are. * int : length of clv we are decoding * int : tree id to use for proto tree. * * Output: * void, but we will add to proto tree if !NULL. */ void isis_dissect_hostname_clv(tvbuff_t *tvb, proto_tree *tree, int offset, int length, int tree_id) { proto_item* ti = proto_tree_add_item( tree, tree_id, tvb, offset, length, ENC_ASCII|ENC_NA); if ( length == 0 ) { proto_item_append_text(ti, "--none--" ); } } void isis_dissect_mt_clv(tvbuff_t *tvb, packet_info* pinfo, proto_tree *tree, int offset, int length, int tree_id, expert_field* mtid_expert) { guint16 mt_block; const char *mt_desc; while (length>0) { /* length can only be a multiple of 2, otherwise there is something broken -> so decode down until length is 1 */ if (length!=1) { /* fetch two bytes */ mt_block=tvb_get_ntohs(tvb, offset); /* mask out the lower 12 bits */ switch(mt_block&0x0fff) { case 0: mt_desc="IPv4 unicast"; break; case 1: mt_desc="In-Band Management"; break; case 2: mt_desc="IPv6 unicast"; break; case 3: mt_desc="Multicast"; break; case 4095: mt_desc="Development, Experimental or Proprietary"; break; default: mt_desc="Reserved for IETF Consensus"; break; } proto_tree_add_uint_format ( tree, tree_id, tvb, offset, 2, mt_block, "%s Topology (0x%03x), %ssubTLVs present%s", mt_desc, mt_block&0xfff, (mt_block&0x8000) ? "" : "no ", (mt_block&0x4000) ? ", ATT bit set" : "" ); } else { proto_tree_add_expert( tree, pinfo, mtid_expert, tvb, offset, 1); break; } length -= 2; offset += 2; } } /* * Name: isis_dissect_ip_int_clv() * * Description: * Take apart the CLV that lists all the IP interfaces. The * meaning of which is slightly different for the different base packet * types, but the display is not different. What we have is n ip * addresses, plain and simple. * * Input: * tvbuff_t * : tvbuffer for packet data * proto_tree * : protocol display tree to fill out. May be NULL * int : offset into packet data where we are. * int : length of clv we are decoding * int : tree id to use for proto tree. * * Output: * void, but we will add to proto tree if !NULL. */ void isis_dissect_ip_int_clv(proto_tree *tree, packet_info* pinfo, tvbuff_t *tvb, expert_field* expert, int offset, int length, int tree_id) { if ( length <= 0 ) { return; } while ( length > 0 ) { if ( length < 4 ) { proto_tree_add_expert_format(tree, pinfo, expert, tvb, offset, -1, "Short IP interface address (%d vs 4)",length ); return; } if ( tree ) { proto_tree_add_item(tree, tree_id, tvb, offset, 4, ENC_BIG_ENDIAN); } offset += 4; length -= 4; } } /* * Name: isis_dissect_ipv6_int_clv() * * Description: * Take apart the CLV that lists all the IPv6 interfaces. The * meaning of which is slightly different for the different base packet * types, but the display is not different. What we have is n ip * addresses, plain and simple. * * Input: * tvbuff_t * : tvbuffer for packet data * proto_tree * : protocol display tree to fill out. May be NULL * int : offset into packet data where we are. * int : length of clv we are decoding * int : tree id to use for proto tree. * * Output: * void, but we will add to proto tree if !NULL. */ void isis_dissect_ipv6_int_clv(proto_tree *tree, packet_info* pinfo, tvbuff_t *tvb, expert_field* expert, int offset, int length, int tree_id) { struct e_in6_addr addr; if ( length <= 0 ) { return; } while ( length > 0 ) { if ( length < 16 ) { proto_tree_add_expert_format(tree, pinfo, expert, tvb, offset, -1, "Short IPv6 interface address (%d vs 16)",length ); return; } tvb_get_ipv6(tvb, offset, &addr); if ( tree ) { proto_tree_add_ipv6(tree, tree_id, tvb, offset, 16, &addr); } offset += 16; length -= 16; } } /* * Name: isis_dissect_te_router_id_clv() * * Description: * Display the Traffic Engineering Router ID TLV #134. * This TLV is like the IP Interface TLV, except that * only _one_ IP address is present * * Input: * tvbuff_t * : tvbuffer for packet data * proto_tree * : protocol display tree to fill out. May be NULL * int : offset into packet data where we are. * int : length of clv we are decoding * int : tree id to use for proto tree. * * Output: * void, but we will add to proto tree if !NULL. */ void isis_dissect_te_router_id_clv(proto_tree *tree, packet_info* pinfo, tvbuff_t *tvb, expert_field* expert, int offset, int length, int tree_id) { if ( length <= 0 ) { return; } if ( length != 4 ) { proto_tree_add_expert_format(tree, pinfo, expert, tvb, offset, -1, "malformed Traffic Engineering Router ID (%d vs 4)",length ); return; } proto_tree_add_item(tree, tree_id, tvb, offset, 4, ENC_BIG_ENDIAN); } /* * Name: isis_dissect_nlpid_clv() * * Description: * Take apart a NLPID packet and display it. The NLPID (for intergrated * ISIS, contains n network layer protocol IDs that the box supports. * We max out at 256 entries. * * Input: * tvbuff_t * : tvbuffer for packet data * proto_tree * : protocol display tree to fill out. May be NULL * int : offset into packet data where we are. * int : length of clv we are decoding * * Output: * void, but we will add to proto tree if !NULL. */ void isis_dissect_nlpid_clv(tvbuff_t *tvb, proto_tree *tree, int hf_nlpid, int offset, int length) { gboolean first; proto_item *ti; if ( !tree ) return; /* nothing to do! */ if (length <= 0) { proto_tree_add_item(tree, hf_nlpid, tvb, offset, length, ENC_NA); } else { first = TRUE; ti = proto_tree_add_bytes_format(tree, hf_nlpid, tvb, offset, length, NULL, "NLPID(s): "); while (length-- > 0 ) { if (!first) { proto_item_append_text(ti, ", "); } proto_item_append_text(ti, "%s (0x%02x)", /* NLPID_IEEE_8021AQ conflicts with NLPID_SNDCF. * In this context, we want the former. */ (tvb_get_guint8(tvb, offset) == NLPID_IEEE_8021AQ ? "IEEE 802.1aq (SPB)" : val_to_str_const(tvb_get_guint8(tvb, offset), nlpid_vals, "Unknown")), tvb_get_guint8(tvb, offset)); offset++; first = FALSE; } } } /* * Name: isis_dissect_clvs() * * Description: * Dispatch routine to shred all the CLVs in a packet. We just * walk through the clv entries in the packet. For each one, we * search the passed in valid clv's for this protocol (opts) for * a matching code. If found, we add to the display tree and * then call the dissector. If it is not, we just post an * "unknown" clv entry using the passed in unknown clv tree id. * * Input: * tvbuff_t * : tvbuffer for packet data * proto_tree * : protocol display tree to fill out. May be NULL * int : offset into packet data where we are. * isis_clv_handle_t * : NULL dissector terminated array of codes * and handlers (along with tree text and tree id's). * int : length of CLV area. * int : length of IDs in packet. * int : unknown clv tree id * * Output: * void, but we will add to proto tree if !NULL. */ void isis_dissect_clvs(tvbuff_t *tvb, packet_info* pinfo, proto_tree *tree, int offset, const isis_clv_handle_t *opts, expert_field* expert_short_len, int len, int id_length, int unknown_tree_id _U_, int tree_type, int tree_length, expert_field ei_unknown) { guint8 code; guint8 length; int q; proto_tree *clv_tree; while ( len > 0 ) { code = tvb_get_guint8(tvb, offset); offset += 1; len -= 1; if (len == 0) break; length = tvb_get_guint8(tvb, offset); offset += 1; len -= 1; if (len == 0) break; if ( len < length ) { proto_tree_add_expert_format(tree, pinfo, expert_short_len, tvb, offset, -1, "Short CLV header (%d vs %d)", length, len ); return; } q = 0; while ((opts[q].dissect != NULL )&&( opts[q].optcode != code )){ q++; } if ( opts[q].dissect ) { /* adjust by 2 for code/len octets */ clv_tree = proto_tree_add_subtree_format(tree, tvb, offset - 2, length + 2, *opts[q].tree_id, NULL, "%s (t=%u, l=%u)", opts[q].tree_text, opts[q].optcode, length); proto_tree_add_item(clv_tree, tree_type, tvb, offset - 2, 1, ENC_BIG_ENDIAN); proto_tree_add_item(clv_tree, tree_length, tvb, offset - 1, 1, ENC_BIG_ENDIAN); opts[q].dissect(tvb, pinfo, clv_tree, offset, id_length, length); } else { clv_tree = proto_tree_add_subtree_format(tree, tvb, offset - 2, length + 2, unknown_tree_id, NULL, "Unknown code (t=%u, l=%u)", code, length); proto_tree_add_item(clv_tree, tree_type, tvb, offset - 2, 1, ENC_BIG_ENDIAN); proto_tree_add_item(clv_tree, tree_length, tvb, offset - 1, 1, ENC_BIG_ENDIAN); proto_tree_add_expert_format(clv_tree, pinfo, &ei_unknown, tvb, offset, length -2, "Dissector for IS-IS CLV (%d)" " code not implemented, Contact Wireshark developers if you want this supported", code); } offset += length; len -= length; } } /* * Editor modelines - http://www.wireshark.org/tools/modelines.html * * Local variables: * c-basic-offset: 4 * tab-width: 8 * indent-tabs-mode: nil * End: * * vi: set shiftwidth=4 tabstop=8 expandtab: * :indentSize=4:tabSize=8:noTabs=true: */