X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/f0f2e6d058c90f758bc13c119d738317b2452911..d7b497cac78b6e22a66a6bae9bdec60a8044f67a:/print-vtp.c diff --git a/print-vtp.c b/print-vtp.c index 9fe86e3c..04054112 100644 --- a/print-vtp.c +++ b/print-vtp.c @@ -12,24 +12,22 @@ * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE. * - * VLAN TRUNKING PROTOCOL (VTP) - * * Reference documentation: - * http://www.cisco.com/en/US/tech/tk389/tk689/technologies_tech_note09186a0080094c52.shtml - * http://www.cisco.com/warp/public/473/21.html - * http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm + * http://www.cisco.com/c/en/us/support/docs/lan-switching/vtp/10558-21.html + * http://docstore.mik.ua/univercd/cc/td/doc/product/lan/trsrb/frames.htm * * Original code ode by Carles Kishimoto */ -#define NETDISSECT_REWORKED +/* \summary: Cisco VLAN Trunking Protocol (VTP) printer */ + #ifdef HAVE_CONFIG_H #include "config.h" #endif -#include +#include -#include "interface.h" +#include "netdissect.h" #include "addrtoname.h" #include "extract.h" @@ -37,7 +35,7 @@ #define VTP_DOMAIN_NAME_LEN 32 #define VTP_MD5_DIGEST_LEN 16 #define VTP_UPDATE_TIMESTAMP_LEN 12 -#define VTP_VLAN_INFO_OFFSET 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 @@ -121,7 +119,7 @@ void vtp_print (netdissect_options *ndo, const u_char *pptr, u_int length) { - int type, len, tlv_len, tlv_value; + int type, len, tlv_len, tlv_value, mgmtd_len; const u_char *tptr; const struct vtp_vlan_ *vtp_vlan; @@ -132,11 +130,11 @@ vtp_print (netdissect_options *ndo, ND_TCHECK2(*tptr, VTP_HEADER_LEN); - type = *(tptr+1); + type = EXTRACT_U_1(tptr + 1); ND_PRINT((ndo, "VTPv%u, Message %s (0x%02x), length %u", - *tptr, + EXTRACT_U_1(tptr), tok2str(vtp_message_type_values,"Unknown message type", type), - *(tptr+1), + type, length)); /* In non-verbose mode, just print version and message type */ @@ -145,10 +143,16 @@ vtp_print (netdissect_options *ndo, } /* verbose mode print all fields */ - ND_PRINT((ndo, "\n\tDomain name: %s, %s: %u", - (tptr+4), - tok2str(vtp_header_values,"Unknown",*(tptr+1)), - *(tptr+2))); + ND_PRINT((ndo, "\n\tDomain name: ")); + mgmtd_len = EXTRACT_U_1(tptr + 3); + if (mgmtd_len < 1 || mgmtd_len > 32) { + ND_PRINT((ndo, " [invalid MgmtD Len %d]", mgmtd_len)); + return; + } + fn_printzp(ndo, tptr + 4, mgmtd_len, NULL); + ND_PRINT((ndo, ", %s: %u", + tok2str(vtp_header_values, "Unknown", type), + EXTRACT_U_1(tptr + 2))); tptr += VTP_HEADER_LEN; @@ -161,9 +165,9 @@ vtp_print (netdissect_options *ndo, * * 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 | MmgtD Len | + * | Version | Code | Followers | MgmtD Len | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - * | Management Domain Name | + * | Management Domain Name (zero-padded to 32 bytes) | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Configuration revision number | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ @@ -176,20 +180,23 @@ vtp_print (netdissect_options *ndo, * */ + ND_TCHECK_8(tptr); ND_PRINT((ndo, "\n\t Config Rev %x, Updater %s", - EXTRACT_32BITS(tptr), + EXTRACT_BE_U_4(tptr), ipaddr_string(ndo, tptr+4))); tptr += 8; + ND_TCHECK2(*tptr, VTP_UPDATE_TIMESTAMP_LEN); ND_PRINT((ndo, ", Timestamp 0x%08x 0x%08x 0x%08x", - EXTRACT_32BITS(tptr), - EXTRACT_32BITS(tptr + 4), - EXTRACT_32BITS(tptr + 8))); + EXTRACT_BE_U_4(tptr), + EXTRACT_BE_U_4(tptr + 4), + EXTRACT_BE_U_4(tptr + 8))); tptr += VTP_UPDATE_TIMESTAMP_LEN; + ND_TCHECK2(*tptr, VTP_MD5_DIGEST_LEN); ND_PRINT((ndo, ", MD5 digest: %08x%08x%08x%08x", - EXTRACT_32BITS(tptr), - EXTRACT_32BITS(tptr + 4), - EXTRACT_32BITS(tptr + 8), - EXTRACT_32BITS(tptr + 12))); + EXTRACT_BE_U_4(tptr), + EXTRACT_BE_U_4(tptr + 4), + EXTRACT_BE_U_4(tptr + 8), + EXTRACT_BE_U_4(tptr + 12))); tptr += VTP_MD5_DIGEST_LEN; break; @@ -200,9 +207,9 @@ vtp_print (netdissect_options *ndo, * * 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 | MmgtD Len | + * | Version | Code | Seq number | MgmtD Len | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - * | Management Domain Name | + * | Management Domain Name (zero-padded to 32 bytes) | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Configuration revision number | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ @@ -215,7 +222,8 @@ vtp_print (netdissect_options *ndo, * */ - ND_PRINT((ndo, ", Config Rev %x", EXTRACT_32BITS(tptr))); + ND_TCHECK_4(tptr); + ND_PRINT((ndo, ", Config Rev %x", EXTRACT_BE_U_4(tptr))); /* * VLAN INFORMATION @@ -235,95 +243,116 @@ vtp_print (netdissect_options *ndo, tptr += 4; while (tptr < (pptr+length)) { + ND_TCHECK_1(tptr); len = *tptr; if (len == 0) break; ND_TCHECK2(*tptr, len); - vtp_vlan = (struct vtp_vlan_*)tptr; - ND_PRINT((ndo, "\n\tVLAN info status %s, type %s, VLAN-id %u, MTU %u, SAID 0x%08x, Name %s", + vtp_vlan = (const struct vtp_vlan_*)tptr; + if (len < VTP_VLAN_INFO_FIXED_PART_LEN) + goto trunc; + ND_TCHECK(*vtp_vlan); + ND_PRINT((ndo, "\n\tVLAN info status %s, type %s, VLAN-id %u, MTU %u, SAID 0x%08x, Name ", tok2str(vtp_vlan_status,"Unknown",vtp_vlan->status), tok2str(vtp_vlan_type_values,"Unknown",vtp_vlan->type), - EXTRACT_16BITS(&vtp_vlan->vlanid), - EXTRACT_16BITS(&vtp_vlan->mtu), - EXTRACT_32BITS(&vtp_vlan->index), - (tptr + VTP_VLAN_INFO_OFFSET))); - - /* - * Vlan names are aligned to 32-bit boundaries. - */ - len -= VTP_VLAN_INFO_OFFSET + 4*((vtp_vlan->name_len + 3)/4); - tptr += VTP_VLAN_INFO_OFFSET + 4*((vtp_vlan->name_len + 3)/4); + EXTRACT_BE_U_2(&vtp_vlan->vlanid), + EXTRACT_BE_U_2(&vtp_vlan->mtu), + EXTRACT_BE_U_4(&vtp_vlan->index))); + len -= VTP_VLAN_INFO_FIXED_PART_LEN; + tptr += VTP_VLAN_INFO_FIXED_PART_LEN; + if (len < 4*((vtp_vlan->name_len + 3)/4)) + goto trunc; + ND_TCHECK2(*tptr, vtp_vlan->name_len); + fn_printzp(ndo, tptr, vtp_vlan->name_len, NULL); + + /* + * Vlan names are aligned to 32-bit boundaries. + */ + len -= 4*((vtp_vlan->name_len + 3)/4); + tptr += 4*((vtp_vlan->name_len + 3)/4); /* TLV information follows */ while (len > 0) { /* - * Cisco specs says 2 bytes for type + 2 bytes for length, take only 1 - * See: http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm + * Cisco specs say 2 bytes for type + 2 bytes for length; + * see http://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 trunc; + ND_TCHECK_2(tptr); type = *tptr; - tlv_len = *(tptr+1); + tlv_len = EXTRACT_U_1(tptr + 1); ND_PRINT((ndo, "\n\t\t%s (0x%04x) TLV", tok2str(vtp_vlan_tlv_values, "Unknown", type), type)); - /* - * infinite loop check - */ - if (type == 0 || tlv_len == 0) { + if (len < tlv_len * 2 + 2) { + ND_PRINT((ndo, " (TLV goes past the end of the packet)")); return; } - ND_TCHECK2(*tptr, tlv_len * 2 +2); - tlv_value = EXTRACT_16BITS(tptr+2); - - switch (type) { - case VTP_VLAN_STE_HOP_COUNT: - ND_PRINT((ndo, ", %u", tlv_value)); - break; - - case VTP_VLAN_PRUNING: - ND_PRINT((ndo, ", %s (%u)", - tlv_value == 1 ? "Enabled" : "Disabled", - tlv_value)); - break; - - case VTP_VLAN_STP_TYPE: - ND_PRINT((ndo, ", %s (%u)", - tok2str(vtp_stp_type_values, "Unknown", tlv_value), - tlv_value)); - break; - - case VTP_VLAN_BRIDGE_TYPE: - ND_PRINT((ndo, ", %s (%u)", - tlv_value == 1 ? "SRB" : "SRT", - tlv_value)); - break; - - case VTP_VLAN_BACKUP_CRF_MODE: - ND_PRINT((ndo, ", %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; + /* + * We assume the value is a 2-byte integer; the length is + * in units of 16-bit words. + */ + if (tlv_len != 1) { + ND_PRINT((ndo, " (invalid TLV length %u != 1)", tlv_len)); + return; + } else { + tlv_value = EXTRACT_BE_U_2(tptr + 2); + + switch (type) { + case VTP_VLAN_STE_HOP_COUNT: + ND_PRINT((ndo, ", %u", tlv_value)); + break; + + case VTP_VLAN_PRUNING: + ND_PRINT((ndo, ", %s (%u)", + tlv_value == 1 ? "Enabled" : "Disabled", + tlv_value)); + break; + + case VTP_VLAN_STP_TYPE: + ND_PRINT((ndo, ", %s (%u)", + tok2str(vtp_stp_type_values, "Unknown", tlv_value), + tlv_value)); + break; + + case VTP_VLAN_BRIDGE_TYPE: + ND_PRINT((ndo, ", %s (%u)", + tlv_value == 1 ? "SRB" : "SRT", + tlv_value)); + break; + + case VTP_VLAN_BACKUP_CRF_MODE: + ND_PRINT((ndo, ", %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; @@ -338,16 +367,17 @@ vtp_print (netdissect_options *ndo, * * 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 | MmgtD Len | + * | Version | Code | Reserved | MgmtD Len | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - * | Management Domain Name | + * | Management Domain Name (zero-padded to 32 bytes) | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | Start value | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * */ - ND_PRINT((ndo, "\n\tStart value: %u", EXTRACT_32BITS(tptr))); + ND_TCHECK_4(tptr); + ND_PRINT((ndo, "\n\tStart value: %u", EXTRACT_BE_U_4(tptr))); break; case VTP_JOIN_MESSAGE: