diff options
Diffstat (limited to 'epan/dissectors/packet-isis-snp.c')
| -rw-r--r-- | epan/dissectors/packet-isis-snp.c | 595 |
1 files changed, 595 insertions, 0 deletions
diff --git a/epan/dissectors/packet-isis-snp.c b/epan/dissectors/packet-isis-snp.c new file mode 100644 index 0000000000..34b6109961 --- /dev/null +++ b/epan/dissectors/packet-isis-snp.c @@ -0,0 +1,595 @@ +/* packet-isis-snp.c + * Routines for decoding isis complete & partial SNP and their payload + * + * $Id$ + * Stuart Stanley <stuarts@mxmail.net> + * + * Ethereal - Network traffic analyzer + * By Gerald Combs <gerald@ethereal.com> + * 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 <stdio.h> +#include <string.h> +#include <glib.h> +#include <epan/packet.h> +#include "packet-osi.h" +#include "packet-isis.h" +#include "packet-isis-clv.h" +#include "packet-isis-lsp.h" +#include "packet-isis-snp.h" + +/* csnp packets */ +static int hf_isis_csnp_pdu_length = -1; +static gint ett_isis_csnp = -1; +static gint ett_isis_csnp_clv_lsp_entries = -1; +static gint ett_isis_csnp_lsp_entry = -1; +static gint ett_isis_csnp_clv_authentication = -1; +static gint ett_isis_csnp_clv_ip_authentication = -1; +static gint ett_isis_csnp_clv_checksum = -1; +static gint ett_isis_csnp_clv_unknown = -1; + +/* psnp packets */ +static int hf_isis_psnp_pdu_length = -1; +static gint ett_isis_psnp = -1; +static gint ett_isis_psnp_clv_lsp_entries = -1; +static gint ett_isis_psnp_lsp_entry = -1; +static gint ett_isis_psnp_clv_authentication = -1; +static gint ett_isis_psnp_clv_ip_authentication = -1; +static gint ett_isis_psnp_clv_checksum = -1; +static gint ett_isis_psnp_clv_unknown = -1; + +static void dissect_snp_authentication_clv(tvbuff_t *tvb, + proto_tree *tree, int offset, int id_length, int length); +static void dissect_snp_ip_authentication_clv(tvbuff_t *tvb, + proto_tree *tree, int offset, int id_length, int length); +static void dissect_snp_checksum_clv(tvbuff_t *tvb, + proto_tree *tree, int offset, int id_length, int length); +static void dissect_snp_lsp_entries_clv(tvbuff_t *tvb, + proto_tree *tree, int offset, int id_length, int length); + +static const isis_clv_handle_t clv_l1_csnp_opts[] = { + { + ISIS_CLV_LSP_ENTRIES, + "LSP entries", + &ett_isis_csnp_clv_lsp_entries, + dissect_snp_lsp_entries_clv + }, + { + ISIS_CLV_AUTHENTICATION, + "Authentication", + &ett_isis_csnp_clv_authentication, + dissect_snp_authentication_clv + }, + { + ISIS_CLV_IP_AUTHENTICATION, + "IP Authentication", + &ett_isis_csnp_clv_ip_authentication, + dissect_snp_ip_authentication_clv + }, + { + ISIS_CLV_CHECKSUM, + "Checksum", + &ett_isis_csnp_clv_checksum, + dissect_snp_checksum_clv + }, + { + 0, "", NULL, NULL + } +}; + +static const isis_clv_handle_t clv_l2_csnp_opts[] = { + { + ISIS_CLV_LSP_ENTRIES, + "LSP entries", + &ett_isis_csnp_clv_lsp_entries, + dissect_snp_lsp_entries_clv + }, + { + ISIS_CLV_AUTHENTICATION, + "Authentication", + &ett_isis_csnp_clv_authentication, + dissect_snp_authentication_clv + }, + { + ISIS_CLV_IP_AUTHENTICATION, + "IP Authentication", + &ett_isis_csnp_clv_ip_authentication, + dissect_snp_ip_authentication_clv + }, + { + ISIS_CLV_CHECKSUM, + "Checksum", + &ett_isis_csnp_clv_checksum, + dissect_snp_checksum_clv + }, + { + 0, "", NULL, NULL + } +}; + +static const isis_clv_handle_t clv_l1_psnp_opts[] = { + { + ISIS_CLV_LSP_ENTRIES, + "LSP entries", + &ett_isis_psnp_clv_lsp_entries, + dissect_snp_lsp_entries_clv + }, + { + ISIS_CLV_AUTHENTICATION, + "Authentication", + &ett_isis_psnp_clv_authentication, + dissect_snp_authentication_clv + }, + { + ISIS_CLV_IP_AUTHENTICATION, + "IP Authentication", + &ett_isis_psnp_clv_ip_authentication, + dissect_snp_ip_authentication_clv + }, + { + ISIS_CLV_CHECKSUM, + "Checksum", + &ett_isis_psnp_clv_checksum, + dissect_snp_checksum_clv + }, + { + 0, "", NULL, NULL + } +}; + +static const isis_clv_handle_t clv_l2_psnp_opts[] = { + { + ISIS_CLV_LSP_ENTRIES, + "LSP entries", + &ett_isis_psnp_clv_lsp_entries, + dissect_snp_lsp_entries_clv + }, + { + ISIS_CLV_AUTHENTICATION, + "Authentication", + &ett_isis_psnp_clv_authentication, + dissect_snp_authentication_clv + }, + { + ISIS_CLV_IP_AUTHENTICATION, + "IP Authentication", + &ett_isis_psnp_clv_ip_authentication, + dissect_snp_ip_authentication_clv + }, + { + ISIS_CLV_CHECKSUM, + "Checksum", + &ett_isis_psnp_clv_checksum, + dissect_snp_checksum_clv + }, + { + 0, "", NULL, NULL + } +}; + +/* + * Name: dissect_snp_lsp_entries_clv() + * + * Description: + * All the snp packets use a common payload format. We have up + * to n entries (based on length), which are made of: + * 2 : remaining life time + * id_length : lsp id + * 4 : sequence number + * 2 : checksum + * + * 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 IDs in packet. + * int : length of payload to decode. + * + * Output: + * void, but we will add to proto tree if !NULL. + */ +static void +dissect_snp_lsp_entries_clv(tvbuff_t *tvb, proto_tree *tree, int offset, + int id_length, int length) +{ + proto_tree *subtree,*ti; + + while ( length > 0 ) { + if ( length < 2+id_length+2+4+2 ) { + isis_dissect_unknown(tvb, tree, offset, + "Short SNP header entry (%d vs %d)", length, + 2+id_length+2+4+2 ); + return; + } + + ti = proto_tree_add_text(tree, tvb, offset, 2+id_length+2+4+2, + "LSP-ID: %s, Sequence: 0x%08x, Lifetime: %5us, Checksum: 0x%04x", + print_system_id( tvb_get_ptr(tvb, offset+2, id_length+2), id_length+2 ), + tvb_get_ntohl(tvb, offset+2+id_length+2), + tvb_get_ntohs(tvb, offset), + tvb_get_ntohs(tvb, offset+2+id_length+2+4)); + + subtree = proto_item_add_subtree(ti,ett_isis_csnp_lsp_entry); + + proto_tree_add_text(subtree, tvb, offset+2, 8, + "LSP-ID: : %s", + print_system_id( tvb_get_ptr(tvb, offset+2, id_length+2), id_length+2 )); + + proto_tree_add_text(subtree, tvb, offset+2+id_length+2, 4, + "LSP Sequence Number : 0x%08x", + tvb_get_ntohl(tvb, offset+2+id_length+2)); + + proto_tree_add_text(subtree, tvb, offset, 2, + "Remaining Lifetime : %us", + tvb_get_ntohs(tvb, offset)); + + proto_tree_add_text(subtree, tvb, offset+2+id_length+2+4, 2, + "LSP checksum : 0x%04x", + tvb_get_ntohs(tvb, offset+2+id_length+2+4)); + + length -= 2+id_length+2+4+2; + offset += 2+id_length+2+4+2; + } + +} + + +/* + * Name: isis_dissect_isis_csnp() + * + * Description: + * Tear apart a L1 or L2 CSNP header and then call into payload dissect + * to pull apart the lsp id payload. + * + * Input: + * tvbuff_t * : tvbuffer for packet data + * proto_tree * : protocol display tree to add to. May be NULL. + * int offset : our offset into packet data. + * int : type (l1 csnp, l2 csnp) + * int : header length of packet. + * int : length of IDs in packet. + * + * Output: + * void, but we will add to proto tree if !NULL. + */ +void +isis_dissect_isis_csnp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int offset, + int type, int header_length, int id_length) +{ + proto_item *ti; + proto_tree *csnp_tree = NULL; + guint16 pdu_length; + int len; + + if (tree) { + ti = proto_tree_add_text(tree, tvb, offset, -1, + PROTO_STRING_CSNP); + csnp_tree = proto_item_add_subtree(ti, ett_isis_csnp); + } + + pdu_length = tvb_get_ntohs(tvb, offset); + if (tree) { + proto_tree_add_uint(csnp_tree, hf_isis_csnp_pdu_length, tvb, + offset, 2, pdu_length); + } + offset += 2; + + if (tree) { + proto_tree_add_text(csnp_tree, tvb, offset, id_length + 1, + "Source-ID: %s", + print_system_id( tvb_get_ptr(tvb, offset, id_length+1), id_length+1 ) ); + } + if (check_col(pinfo->cinfo, COL_INFO)) { + col_append_fstr(pinfo->cinfo, COL_INFO, ", Source-ID: %s", + print_system_id( tvb_get_ptr(tvb, offset, id_length+1), id_length+1 ) ); + } + offset += id_length + 1; + + if (tree) { + proto_tree_add_text(csnp_tree, tvb, offset, id_length + 2, + "Start LSP-ID: %s", + print_system_id( tvb_get_ptr(tvb, offset, id_length+2), id_length+2 ) ); + } + if (check_col(pinfo->cinfo, COL_INFO)) { + col_append_fstr(pinfo->cinfo, COL_INFO, ", Start LSP-ID: %s", + print_system_id( tvb_get_ptr(tvb, offset, id_length+2), id_length+2 ) ); + } + offset += id_length + 2; + + if (tree) { + proto_tree_add_text(csnp_tree, tvb, offset, id_length + 2, + "End LSP-ID: %s", + print_system_id( tvb_get_ptr(tvb, offset, id_length+2), id_length+2 ) ); + } + if (check_col(pinfo->cinfo, COL_INFO)) { + col_append_fstr(pinfo->cinfo, COL_INFO, ", End LSP-ID: %s", + print_system_id( tvb_get_ptr(tvb, offset, id_length+2), id_length+2 ) ); + } + offset += id_length + 2; + + len = pdu_length - header_length; + if (len < 0) { + return; + } + /* Call into payload dissector */ + if (type == ISIS_TYPE_L1_CSNP ) { + isis_dissect_clvs(tvb, csnp_tree, offset, + clv_l1_csnp_opts, len, id_length, + ett_isis_csnp_clv_unknown ); + } else { + isis_dissect_clvs(tvb, csnp_tree, offset, + clv_l2_csnp_opts, len, id_length, + ett_isis_csnp_clv_unknown ); + } +} + +/* + * Name: isis_dissect_isis_psnp() + * + * Description: + * Tear apart a L1 or L2 PSNP header and then call into payload dissect + * to pull apart the lsp id payload. + * + * Input: + * tvbuff_t * : tvbuffer for packet data + * proto_tree * : protocol display tree to add to. May be NULL. + * int : our offset into packet data + * int : type (l1 psnp, l2 psnp) + * int : header length of packet. + * int : length of IDs in packet. + * + * Output: + * void, but we will add to proto tree if !NULL. + */ +void +isis_dissect_isis_psnp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int offset, + int type, int header_length, int id_length) +{ + proto_item *ti; + proto_tree *psnp_tree = NULL; + guint16 pdu_length; + int len; + + if (tree) { + ti = proto_tree_add_text(tree, tvb, offset, -1, + PROTO_STRING_PSNP); + psnp_tree = proto_item_add_subtree(ti, ett_isis_psnp); + } + + pdu_length = tvb_get_ntohs(tvb, offset); + if (tree) { + proto_tree_add_uint(psnp_tree, hf_isis_psnp_pdu_length, tvb, + offset, 2, pdu_length); + } + offset += 2; + + if (tree) { + proto_tree_add_text(psnp_tree, tvb, offset, id_length + 1, + "Source-ID: %s", + print_system_id( tvb_get_ptr(tvb, offset, id_length+1), id_length + 1 ) ); + } + if (check_col(pinfo->cinfo, COL_INFO)) { + col_append_fstr(pinfo->cinfo, COL_INFO, ", Source-ID: %s", + print_system_id( tvb_get_ptr(tvb, offset, id_length+1), id_length+1 ) ); + } + offset += id_length + 1; + + len = pdu_length - header_length; + if (len < 0) { + isis_dissect_unknown(tvb, tree, offset, + "packet header length %d went beyond packet", + header_length ); + return; + } + /* Call into payload dissector */ + if (type == ISIS_TYPE_L1_PSNP ) { + isis_dissect_clvs(tvb, psnp_tree, offset, + clv_l1_psnp_opts, len, id_length, + ett_isis_psnp_clv_unknown ); + } else { + isis_dissect_clvs(tvb, psnp_tree, offset, + clv_l2_psnp_opts, len, id_length, + ett_isis_psnp_clv_unknown ); + } +} + +/* + * Name: dissect_snp_authentication_clv() + * + * Description: + * Decode for a snp packets authenticaion clv. + * Calls into the CLV common one. + * + * Input: + * tvbuff_t * : tvbuffer for packet data + * proto_tree * : proto tree to build on (may be null) + * int : current offset into packet data + * int : length of IDs in packet. + * int : length of this clv + * + * Output: + * void, will modify proto_tree if not null. + */ +static void +dissect_snp_authentication_clv(tvbuff_t *tvb, proto_tree *tree, int offset, + int id_length _U_, int length) +{ + isis_dissect_authentication_clv(tvb, tree, offset, length); +} + +/* + * Name: dissect_snp_ip_authentication_clv() + * + * Description: + * Decode for a snp packets authenticaion clv. + * Calls into the CLV common one. + * + * Input: + * tvbuff_t * : tvbuffer for packet data + * proto_tree * : proto tree to build on (may be null) + * int : current offset into packet data + * int : length of IDs in packet. + * int : length of this clv + * + * Output: + * void, will modify proto_tree if not null. + */ +static void +dissect_snp_ip_authentication_clv(tvbuff_t *tvb, proto_tree *tree, int offset, + int id_length _U_, int length) +{ + isis_dissect_ip_authentication_clv(tvb, tree, offset, length); +} + +/* + * Name: dissect_snp_checksum_clv() + * + * Description: + * dump and verify the optional checksum in TLV 12 + * + * 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. + */ + +static void +dissect_snp_checksum_clv(tvbuff_t *tvb, + proto_tree *tree, int offset, int id_length _U_, int length) { + + guint16 pdu_length,checksum, cacl_checksum=0; + + if (tree) { + if ( length != 2 ) { + proto_tree_add_text ( tree, tvb, offset, length, + "incorrect checksum length (%u), should be (2)", length ); + return; + } + + checksum = tvb_get_ntohs(tvb, offset); + + /* the check_and_get_checksum() function needs to know how big + * the packet is. we can either pass through the pdu-len through several layers + * of dissectors and wrappers or extract the PDU length field from the PDU specific header + * which is offseted 8 bytes (relative to the beginning of the IS-IS packet) in SNPs */ + + pdu_length = tvb_get_ntohs(tvb, 8); + + /* unlike the LSP checksum verification which starts at an offset of 12 we start at offset 0*/ + switch (check_and_get_checksum(tvb, 0, pdu_length, checksum, offset, &cacl_checksum)) + { + + case NO_CKSUM : + proto_tree_add_text ( tree, tvb, offset, length, + "Checksum: 0x%04x (unused)", checksum); + break; + case DATA_MISSING : + isis_dissect_unknown(tvb, tree, offset, + "packet length %d went beyond packet", + tvb_length_remaining(tvb, 0)); + break; + case CKSUM_NOT_OK : + proto_tree_add_text ( tree, tvb, offset, length, + "Checksum: 0x%04x (incorrect, should be 0x%04x)", + checksum, + cacl_checksum); + break; + case CKSUM_OK : + proto_tree_add_text ( tree, tvb, offset, length, + "Checksum: 0x%04x (correct)", checksum); + break; + default : + g_message("'check_and_get_checksum' returned an invalid value"); + } + } +} + +/* + * Name: isis_register_csnp() + * + * Description: + * Register our protocol sub-sets with protocol manager. + * + * Input: + * int : protocol index for the ISIS protocol + * + * Output: + * void + */ +void +isis_register_csnp(int proto_isis) { + static hf_register_info hf[] = { + { &hf_isis_csnp_pdu_length, + { "PDU length", "isis.csnp.pdu_length", FT_UINT16, + BASE_DEC, NULL, 0x0, "", HFILL }}, + }; + static gint *ett[] = { + &ett_isis_csnp, + &ett_isis_csnp_clv_lsp_entries, + &ett_isis_csnp_lsp_entry, + &ett_isis_csnp_clv_authentication, + &ett_isis_csnp_clv_ip_authentication, + &ett_isis_csnp_clv_checksum, + &ett_isis_csnp_clv_unknown, + }; + + proto_register_field_array(proto_isis, hf, array_length(hf)); + proto_register_subtree_array(ett, array_length(ett)); +} + + +/* + * Name: isis_register_psnp() + * + * Description: + * Register our protocol sub-sets with protocol manager. + * + * Input: + * int : protocol index for the ISIS protocol + * + * Output: + * void + */ +void +isis_register_psnp(int proto_isis) { + static hf_register_info hf[] = { + { &hf_isis_psnp_pdu_length, + { "PDU length", "isis.psnp.pdu_length", FT_UINT16, + BASE_DEC, NULL, 0x0, "", HFILL }}, + }; + static gint *ett[] = { + &ett_isis_psnp, + &ett_isis_psnp_clv_lsp_entries, + &ett_isis_psnp_lsp_entry, + &ett_isis_psnp_clv_authentication, + &ett_isis_psnp_clv_ip_authentication, + &ett_isis_psnp_clv_checksum, + &ett_isis_psnp_clv_unknown, + }; + + proto_register_field_array(proto_isis, hf, array_length(hf)); + proto_register_subtree_array(ett, array_length(ett)); +} |