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Diffstat (limited to '')
| -rw-r--r-- | print-vtp.c | 392 |
1 files changed, 392 insertions, 0 deletions
diff --git a/print-vtp.c b/print-vtp.c new file mode 100644 index 0000000..bcee64c --- /dev/null +++ b/print-vtp.c @@ -0,0 +1,392 @@ +/* + * Copyright (c) 1998-2007 The TCPDUMP project + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that: (1) source code + * distributions retain the above copyright notice and this paragraph + * in its entirety, and (2) distributions including binary code include + * the above copyright notice and this paragraph in its entirety in + * the documentation or other materials provided with the distribution. + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND + * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT + * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE. + * + * Reference documentation: + * https://www.cisco.com/c/en/us/support/docs/lan-switching/vtp/10558-21.html + * https://docstore.mik.ua/univercd/cc/td/doc/product/lan/trsrb/frames.htm + * + * Original code ode by Carles Kishimoto <carles.kishimoto@gmail.com> + */ + +/* \summary: Cisco VLAN Trunking Protocol (VTP) printer */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include "netdissect-stdinc.h" + +#define ND_LONGJMP_FROM_TCHECK +#include "netdissect.h" +#include "addrtoname.h" +#include "extract.h" + +#define VTP_HEADER_LEN 36 +#define VTP_DOMAIN_NAME_LEN 32 +#define VTP_MD5_DIGEST_LEN 16 +#define VTP_UPDATE_TIMESTAMP_LEN 12 +#define VTP_VLAN_INFO_FIXED_PART_LEN 12 /* length of VLAN info before VLAN name */ + +#define VTP_SUMMARY_ADV 0x01 +#define VTP_SUBSET_ADV 0x02 +#define VTP_ADV_REQUEST 0x03 +#define VTP_JOIN_MESSAGE 0x04 + +struct vtp_vlan_ { + nd_uint8_t len; + nd_uint8_t status; + nd_uint8_t type; + nd_uint8_t name_len; + nd_uint16_t vlanid; + nd_uint16_t mtu; + nd_uint32_t index; +}; + +static const struct tok vtp_message_type_values[] = { + { VTP_SUMMARY_ADV, "Summary advertisement"}, + { VTP_SUBSET_ADV, "Subset advertisement"}, + { VTP_ADV_REQUEST, "Advertisement request"}, + { VTP_JOIN_MESSAGE, "Join message"}, + { 0, NULL } +}; + +static const struct tok vtp_header_values[] = { + { 0x01, "Followers"}, /* On Summary advertisement, 3rd byte is Followers */ + { 0x02, "Seq number"}, /* On Subset advertisement, 3rd byte is Sequence number */ + { 0x03, "Rsvd"}, /* On Adver. requests 3rd byte is Rsvd */ + { 0x04, "Rsvd"}, /* On Adver. requests 3rd byte is Rsvd */ + { 0, NULL } +}; + +static const struct tok vtp_vlan_type_values[] = { + { 0x01, "Ethernet"}, + { 0x02, "FDDI"}, + { 0x03, "TrCRF"}, + { 0x04, "FDDI-net"}, + { 0x05, "TrBRF"}, + { 0, NULL } +}; + +static const struct tok vtp_vlan_status[] = { + { 0x00, "Operational"}, + { 0x01, "Suspended"}, + { 0, NULL } +}; + +#define VTP_VLAN_SOURCE_ROUTING_RING_NUMBER 0x01 +#define VTP_VLAN_SOURCE_ROUTING_BRIDGE_NUMBER 0x02 +#define VTP_VLAN_STP_TYPE 0x03 +#define VTP_VLAN_PARENT_VLAN 0x04 +#define VTP_VLAN_TRANS_BRIDGED_VLAN 0x05 +#define VTP_VLAN_PRUNING 0x06 +#define VTP_VLAN_BRIDGE_TYPE 0x07 +#define VTP_VLAN_ARP_HOP_COUNT 0x08 +#define VTP_VLAN_STE_HOP_COUNT 0x09 +#define VTP_VLAN_BACKUP_CRF_MODE 0x0A + +static const struct tok vtp_vlan_tlv_values[] = { + { VTP_VLAN_SOURCE_ROUTING_RING_NUMBER, "Source-Routing Ring Number TLV"}, + { VTP_VLAN_SOURCE_ROUTING_BRIDGE_NUMBER, "Source-Routing Bridge Number TLV"}, + { VTP_VLAN_STP_TYPE, "STP type TLV"}, + { VTP_VLAN_PARENT_VLAN, "Parent VLAN TLV"}, + { VTP_VLAN_TRANS_BRIDGED_VLAN, "Translationally bridged VLANs TLV"}, + { VTP_VLAN_PRUNING, "Pruning TLV"}, + { VTP_VLAN_BRIDGE_TYPE, "Bridge Type TLV"}, + { VTP_VLAN_ARP_HOP_COUNT, "Max ARP Hop Count TLV"}, + { VTP_VLAN_STE_HOP_COUNT, "Max STE Hop Count TLV"}, + { VTP_VLAN_BACKUP_CRF_MODE, "Backup CRF Mode TLV"}, + { 0, NULL } +}; + +static const struct tok vtp_stp_type_values[] = { + { 1, "SRT"}, + { 2, "SRB"}, + { 3, "Auto"}, + { 0, NULL } +}; + +void +vtp_print(netdissect_options *ndo, + const u_char *pptr, const u_int length) +{ + u_int type, len, name_len, tlv_len, tlv_value, mgmtd_len; + const u_char *tptr; + const struct vtp_vlan_ *vtp_vlan; + + ndo->ndo_protocol = "vtp"; + if (length < VTP_HEADER_LEN) + goto invalid; + + tptr = pptr; + + ND_TCHECK_LEN(tptr, VTP_HEADER_LEN); + + type = GET_U_1(tptr + 1); + ND_PRINT("VTPv%u, Message %s (0x%02x), length %u", + GET_U_1(tptr), + tok2str(vtp_message_type_values,"Unknown message type", type), + type, + length); + + /* In non-verbose mode, just print version and message type */ + if (ndo->ndo_vflag < 1) { + goto tcheck_full_packet; + } + + /* verbose mode print all fields */ + ND_PRINT("\n\tDomain name: "); + mgmtd_len = GET_U_1(tptr + 3); + if (mgmtd_len < 1 || mgmtd_len > VTP_DOMAIN_NAME_LEN) { + ND_PRINT(" [invalid MgmtD Len %u]", mgmtd_len); + goto invalid; + } + nd_printjnp(ndo, tptr + 4, mgmtd_len); + ND_PRINT(", %s: %u", + tok2str(vtp_header_values, "Unknown", type), + GET_U_1(tptr + 2)); + + tptr += VTP_HEADER_LEN; + + switch (type) { + + case VTP_SUMMARY_ADV: + + /* + * SUMMARY ADVERTISEMENT + * + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Version | Code | Followers | MgmtD Len | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Management Domain Name (zero-padded to 32 bytes) | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Configuration revision number | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Updater Identity IP address | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Update Timestamp (12 bytes) | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | MD5 digest (16 bytes) | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + */ + + ND_PRINT("\n\t Config Rev %x, Updater %s", + GET_BE_U_4(tptr), + GET_IPADDR_STRING(tptr+4)); + tptr += 8; + ND_PRINT(", Timestamp 0x%08x 0x%08x 0x%08x", + GET_BE_U_4(tptr), + GET_BE_U_4(tptr + 4), + GET_BE_U_4(tptr + 8)); + tptr += VTP_UPDATE_TIMESTAMP_LEN; + ND_PRINT(", MD5 digest: %08x%08x%08x%08x", + GET_BE_U_4(tptr), + GET_BE_U_4(tptr + 4), + GET_BE_U_4(tptr + 8), + GET_BE_U_4(tptr + 12)); + tptr += VTP_MD5_DIGEST_LEN; + break; + + case VTP_SUBSET_ADV: + + /* + * SUBSET ADVERTISEMENT + * + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Version | Code | Seq number | MgmtD Len | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Management Domain Name (zero-padded to 32 bytes) | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Configuration revision number | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | VLAN info field 1 | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | ................ | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | VLAN info field N | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + */ + + ND_PRINT(", Config Rev %x", GET_BE_U_4(tptr)); + + /* + * VLAN INFORMATION + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | V info len | Status | VLAN type | VLAN name len | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | ISL vlan id | MTU size | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | 802.10 index (SAID) | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | VLAN name | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + */ + + tptr += 4; + while ((unsigned)(tptr - pptr) < length) { + + len = GET_U_1(tptr); + if (len == 0) + break; + + ND_TCHECK_LEN(tptr, len); + + vtp_vlan = (const struct vtp_vlan_*)tptr; + if (len < VTP_VLAN_INFO_FIXED_PART_LEN) + goto invalid; + ND_PRINT("\n\tVLAN info status %s, type %s, VLAN-id %u, MTU %u, SAID 0x%08x, Name ", + tok2str(vtp_vlan_status,"Unknown",GET_U_1(vtp_vlan->status)), + tok2str(vtp_vlan_type_values,"Unknown",GET_U_1(vtp_vlan->type)), + GET_BE_U_2(vtp_vlan->vlanid), + GET_BE_U_2(vtp_vlan->mtu), + GET_BE_U_4(vtp_vlan->index)); + len -= VTP_VLAN_INFO_FIXED_PART_LEN; + tptr += VTP_VLAN_INFO_FIXED_PART_LEN; + name_len = GET_U_1(vtp_vlan->name_len); + if (len < 4*((name_len + 3)/4)) + goto invalid; + nd_printjnp(ndo, tptr, name_len); + + /* + * Vlan names are aligned to 32-bit boundaries. + */ + len -= 4*((name_len + 3)/4); + tptr += 4*((name_len + 3)/4); + + /* TLV information follows */ + + while (len > 0) { + + /* + * Cisco specs say 2 bytes for type + 2 bytes for length; + * see https://docstore.mik.ua/univercd/cc/td/doc/product/lan/trsrb/frames.htm + * However, actual packets on the wire appear to use 1 + * byte for the type and 1 byte for the length, so that's + * what we do. + */ + if (len < 2) + goto invalid; + type = GET_U_1(tptr); + tlv_len = GET_U_1(tptr + 1); + + ND_PRINT("\n\t\t%s (0x%04x) TLV", + tok2str(vtp_vlan_tlv_values, "Unknown", type), + type); + + if (len < tlv_len * 2 + 2) { + ND_PRINT(" (TLV goes past the end of the packet)"); + goto invalid; + } + ND_TCHECK_LEN(tptr, tlv_len * 2 + 2); + + /* + * We assume the value is a 2-byte integer; the length is + * in units of 16-bit words. + */ + if (tlv_len != 1) { + ND_PRINT(" (invalid TLV length %u != 1)", tlv_len); + goto invalid; + } else { + tlv_value = GET_BE_U_2(tptr + 2); + + switch (type) { + case VTP_VLAN_STE_HOP_COUNT: + ND_PRINT(", %u", tlv_value); + break; + + case VTP_VLAN_PRUNING: + ND_PRINT(", %s (%u)", + tlv_value == 1 ? "Enabled" : "Disabled", + tlv_value); + break; + + case VTP_VLAN_STP_TYPE: + ND_PRINT(", %s (%u)", + tok2str(vtp_stp_type_values, "Unknown", tlv_value), + tlv_value); + break; + + case VTP_VLAN_BRIDGE_TYPE: + ND_PRINT(", %s (%u)", + tlv_value == 1 ? "SRB" : "SRT", + tlv_value); + break; + + case VTP_VLAN_BACKUP_CRF_MODE: + ND_PRINT(", %s (%u)", + tlv_value == 1 ? "Backup" : "Not backup", + tlv_value); + break; + + /* + * FIXME those are the defined TLVs that lack a decoder + * you are welcome to contribute code ;-) + */ + + case VTP_VLAN_SOURCE_ROUTING_RING_NUMBER: + case VTP_VLAN_SOURCE_ROUTING_BRIDGE_NUMBER: + case VTP_VLAN_PARENT_VLAN: + case VTP_VLAN_TRANS_BRIDGED_VLAN: + case VTP_VLAN_ARP_HOP_COUNT: + default: + print_unknown_data(ndo, tptr, "\n\t\t ", 2 + tlv_len*2); + break; + } + } + len -= 2 + tlv_len*2; + tptr += 2 + tlv_len*2; + } + } + break; + + case VTP_ADV_REQUEST: + + /* + * ADVERTISEMENT REQUEST + * + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Version | Code | Reserved | MgmtD Len | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Management Domain Name (zero-padded to 32 bytes) | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Start value | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + */ + + ND_PRINT("\n\tStart value: %u", GET_BE_U_4(tptr)); + break; + + case VTP_JOIN_MESSAGE: + + /* FIXME - Could not find message format */ + break; + + default: + break; + } + + return; + +invalid: + nd_print_invalid(ndo); +tcheck_full_packet: + ND_TCHECK_LEN(pptr, length); +} |