/* packet-isis-clv.c * Common CLV decode routines. * * $Id: packet-isis-clv.c,v 1.29 2003/12/08 20:40:32 guy Exp $ * Stuart Stanley * * 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 "packet-osi.h" #include "packet-isis.h" #include "packet-isis-clv.h" #include "nlpid.h" static void free_g_string(void *arg) { g_string_free(arg, TRUE); } /* * 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(tvbuff_t *tvb, proto_tree *tree, int offset, int length) { int arealen,area_idx; GString *gstr; while ( length > 0 ) { arealen = tvb_get_guint8(tvb, offset); length--; if (length<=0) { isis_dissect_unknown(tvb, tree, offset, "short address (no length for payload)"); return; } if ( arealen > length) { isis_dissect_unknown(tvb, tree, offset, "short address, packet says %d, we have %d left", arealen, length ); return; } if ( tree ) { /* * 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 .... * * We pick an initial size of 32 bytes. */ gstr = g_string_sized_new(32); /* * Free the GString if we throw an exception. */ CLEANUP_PUSH(free_g_string, gstr); for (area_idx = 0; area_idx < arealen; area_idx++) { g_string_sprintfa(gstr, "%02x", tvb_get_guint8(tvb, offset+area_idx+1)); if (((area_idx & 1) == 0) && (area_idx + 1 < arealen)) { g_string_sprintfa(gstr, "."); } } /* and spit it out */ proto_tree_add_text ( tree, tvb, offset, arealen + 1, "Area address (%d): %s", arealen, gstr->str ); /* * We're done with the GString, so delete it and * get rid of the cleanup handler. */ CLEANUP_CALL_AND_POP; } offset += arealen + 1; length -= arealen; /* length already adjusted for len fld*/ } } /* * 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(tvbuff_t *tvb, proto_tree *tree, int offset, int length) { guchar pw_type; int auth_unsupported; GString *gstr; if ( length <= 0 ) { return; } pw_type = tvb_get_guint8(tvb, offset); offset += 1; length--; auth_unsupported = FALSE; gstr = g_string_new(""); /* * Free the GString if we throw an exception. */ CLEANUP_PUSH(free_g_string, gstr); switch (pw_type) { case 1: g_string_sprintfa(gstr, "clear text (1), password (length %d) = ", length); if ( length > 0 ) { g_string_sprintfa(gstr, "%s", tvb_format_text(tvb, offset, length)); } else { g_string_append(gstr, "no clear-text password found!!!"); } break; case 54: g_string_sprintfa(gstr, "hmac-md5 (54), password (length %d) = ", length); if ( length == 16 ) { g_string_sprintfa(gstr, "0x%02x", tvb_get_guint8(tvb, offset)); offset += 1; length--; while (length > 0) { g_string_sprintfa(gstr, "%02x", tvb_get_guint8(tvb, offset)); offset += 1; length--; } } else { g_string_append(gstr, "illegal hmac-md5 digest format (must be 16 bytes)"); } break; default: g_string_sprintfa(gstr, "type 0x%02x (0x%02x): ", pw_type, length ); auth_unsupported=TRUE; break; } proto_tree_add_text ( tree, tvb, offset - 1, length + 1, "%s", gstr->str ); /* * We're done with the GString, so delete it and get rid of * the cleanup handler. */ CLEANUP_CALL_AND_POP; if ( auth_unsupported ) { isis_dissect_unknown(tvb, tree, offset, "Unknown authentication type" ); } } /* * Name: isis_ip_authentication_clv() * * Description: * dump the IP authentication information found in TLV 133 * the CLV is standardized in rf1195, however all major * implementations use TLV #10 * 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_ip_authentication_clv(tvbuff_t *tvb, proto_tree *tree, int offset, int length) { if ( !tree ) return; /* nothing to do! */ if ( length != 0 ) { proto_tree_add_text ( tree, tvb, offset, length, "IP Authentication: %.*s", length, tvb_get_ptr(tvb, offset, length) ); } } /* * 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 * * 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) { if ( !tree ) return; /* nothing to do! */ if ( length == 0 ) { proto_tree_add_text ( tree, tvb, offset, length, "Hostname: --none--" ); } else { proto_tree_add_text ( tree, tvb, offset, length, "Hostname: %.*s", length, tvb_get_ptr(tvb, offset, length) ); } } void isis_dissect_mt_clv(tvbuff_t *tvb, proto_tree *tree, int offset, int length, int tree_id) { guint16 mt_block; char mt_desc[60]; 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: strcpy(mt_desc,"IPv4 unicast"); break; case 1: strcpy(mt_desc,"In-Band Management"); break; case 2: strcpy(mt_desc,"IPv6 unicast"); break; case 3: strcpy(mt_desc,"Multicast"); break; case 4095: strcpy(mt_desc,"Development, Experimental or Proprietary"); break; default: strcpy(mt_desc,"Reserved for IETF Consensus"); break; } proto_tree_add_uint_format ( tree, tree_id, tvb, offset, 2, mt_block, "%s Topology (0x%03x)%s%s", mt_desc, mt_block&0xfff, (mt_block&0x8000) ? "" : ", no sub-TLVs present", (mt_block&0x4000) ? ", ATT bit set" : "" ); } else { proto_tree_add_text ( tree, tvb, offset, 1, "malformed MT-ID"); break; } length=length-2; offset=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(tvbuff_t *tvb, proto_tree *tree, int offset, int length, int tree_id) { if ( length <= 0 ) { return; } while ( length > 0 ) { if ( length < 4 ) { isis_dissect_unknown(tvb, tree, offset, "Short IP interface address (%d vs 4)",length ); return; } if ( tree ) { proto_tree_add_item(tree, tree_id, tvb, offset, 4, FALSE); } 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(tvbuff_t *tvb, proto_tree *tree, int offset, int length, int tree_id) { guint8 addr [16]; if ( length <= 0 ) { return; } while ( length > 0 ) { if ( length < 16 ) { isis_dissect_unknown(tvb, tree, offset, "Short IPv6 interface address (%d vs 16)",length ); return; } tvb_memcpy(tvb, addr, offset, sizeof(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(tvbuff_t *tvb, proto_tree *tree, int offset, int length, int tree_id) { if ( length <= 0 ) { return; } if ( length != 4 ) { isis_dissect_unknown(tvb, tree, offset, "malformed Traffic Engineering Router ID (%d vs 4)",length ); return; } if ( tree ) { proto_tree_add_item(tree, tree_id, tvb, offset, 4, FALSE); } } /* * 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. * Our display buffer we use is upto 255 entries, 6 bytes per (0x00, ) * plus 1 for zero termination. We just just 256*6 for simplicity. * * 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 offset, int length) { char sbuf[256*6]; char *s = sbuf; int hlen = length; int old_offset = offset; if ( !tree ) return; /* nothing to do! */ while ( length-- > 0 ) { if (s != sbuf ) { s += sprintf ( s, ", " ); } s += sprintf ( s, "%s (0x%02x)", val_to_str(tvb_get_guint8(tvb, offset), nlpid_vals, "Unknown"), tvb_get_guint8(tvb, offset)); offset++; } if ( hlen == 0 ) { sprintf ( sbuf, "--none--" ); } proto_tree_add_text ( tree, tvb, old_offset, hlen, "NLPID(s): %s", sbuf ); } /* * 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, proto_tree *tree, int offset, const isis_clv_handle_t *opts, int len, int id_length, int unknown_tree_id) { guint8 code; guint8 length; int q; proto_item *ti; proto_tree *clv_tree; int adj; while ( len > 0 ) { code = tvb_get_guint8(tvb, offset); offset += 1; length = tvb_get_guint8(tvb, offset); offset += 1; adj = (sizeof(code) + sizeof(length) + length); len -= adj; if ( len < 0 ) { isis_dissect_unknown(tvb, tree, offset, "Short CLV header (%d vs %d)", adj, len + adj ); return; } q = 0; while ((opts[q].dissect != NULL )&&( opts[q].optcode != code )){ q++; } if ( opts[q].dissect ) { if (tree) { /* adjust by 2 for code/len octets */ ti = proto_tree_add_text(tree, tvb, offset - 2, length + 2, "%s (%u)", opts[q].tree_text, length ); clv_tree = proto_item_add_subtree(ti, *opts[q].tree_id ); } else { clv_tree = NULL; } opts[q].dissect(tvb, clv_tree, offset, id_length, length); } else { if (tree) { ti = proto_tree_add_text(tree, tvb, offset - 2, length + 2, "Unknown code %u (%u)", code, length); clv_tree = proto_item_add_subtree(ti, unknown_tree_id ); } else { clv_tree = NULL; } } offset += length; } }