* FOR A PARTICULAR PURPOSE.
*
* Reference documentation:
- * 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
+ * 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
*
*/
/* \summary: Cisco VLAN Trunking Protocol (VTP) printer */
-#ifdef HAVE_CONFIG_H
-#include "config.h"
-#endif
+#include <config.h>
-#include <netdissect-stdinc.h>
+#include "netdissect-stdinc.h"
+#define ND_LONGJMP_FROM_TCHECK
#include "netdissect.h"
#include "addrtoname.h"
#include "extract.h"
#define VTP_JOIN_MESSAGE 0x04
struct vtp_vlan_ {
- uint8_t len;
- uint8_t status;
- uint8_t type;
- uint8_t name_len;
- uint16_t vlanid;
- uint16_t mtu;
- uint32_t index;
+ 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[] = {
};
void
-vtp_print (netdissect_options *ndo,
- const u_char *pptr, u_int length)
+vtp_print(netdissect_options *ndo,
+ const u_char *pptr, const u_int length)
{
- int type, len, tlv_len, tlv_value, mgmtd_len;
+ 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 trunc;
+ goto invalid;
tptr = pptr;
- ND_TCHECK2(*tptr, VTP_HEADER_LEN);
+ ND_TCHECK_LEN(tptr, VTP_HEADER_LEN);
- type = EXTRACT_U_1(tptr + 1);
- ND_PRINT((ndo, "VTPv%u, Message %s (0x%02x), length %u",
- EXTRACT_U_1(tptr),
+ 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));
+ length);
/* In non-verbose mode, just print version and message type */
if (ndo->ndo_vflag < 1) {
- return;
+ goto tcheck_full_packet;
}
/* verbose mode print all fields */
- 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;
+ ND_PRINT("\n\tDomain name: ");
+ mgmtd_len = GET_U_1(tptr + 3);
+ if (mgmtd_len < 1 || mgmtd_len > VTP_DOMAIN_NAME_LEN) {
+ ND_PRINT(" [MgmtD Len %u]", mgmtd_len);
+ goto invalid;
}
- fn_printzp(ndo, tptr + 4, mgmtd_len, NULL);
- ND_PRINT((ndo, ", %s: %u",
+ nd_printjnp(ndo, tptr + 4, mgmtd_len);
+ ND_PRINT(", %s: %u",
tok2str(vtp_header_values, "Unknown", type),
- EXTRACT_U_1(tptr + 2)));
+ GET_U_1(tptr + 2));
tptr += VTP_HEADER_LEN;
*
*/
- ND_TCHECK_8(tptr);
- ND_PRINT((ndo, "\n\t Config Rev %x, Updater %s",
- EXTRACT_BE_U_4(tptr),
- ipaddr_string(ndo, tptr+4)));
+ ND_PRINT("\n\t Config Rev %x, Updater %s",
+ GET_BE_U_4(tptr),
+ GET_IPADDR_STRING(tptr+4));
tptr += 8;
- ND_TCHECK2(*tptr, VTP_UPDATE_TIMESTAMP_LEN);
- ND_PRINT((ndo, ", Timestamp 0x%08x 0x%08x 0x%08x",
- EXTRACT_BE_U_4(tptr),
- EXTRACT_BE_U_4(tptr + 4),
- EXTRACT_BE_U_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_TCHECK2(*tptr, VTP_MD5_DIGEST_LEN);
- ND_PRINT((ndo, ", MD5 digest: %08x%08x%08x%08x",
- EXTRACT_BE_U_4(tptr),
- EXTRACT_BE_U_4(tptr + 4),
- EXTRACT_BE_U_4(tptr + 8),
- EXTRACT_BE_U_4(tptr + 12)));
+ 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;
*
*/
- ND_TCHECK_4(tptr);
- ND_PRINT((ndo, ", Config Rev %x", EXTRACT_BE_U_4(tptr)));
+ ND_PRINT(", Config Rev %x", GET_BE_U_4(tptr));
/*
* VLAN INFORMATION
*/
tptr += 4;
- while (tptr < (pptr+length)) {
+ while ((unsigned)(tptr - pptr) < length) {
- ND_TCHECK_1(tptr);
- len = *tptr;
+ len = GET_U_1(tptr);
if (len == 0)
break;
- ND_TCHECK2(*tptr, len);
+ ND_TCHECK_LEN(tptr, len);
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_BE_U_2(&vtp_vlan->vlanid),
- EXTRACT_BE_U_2(&vtp_vlan->mtu),
- EXTRACT_BE_U_4(&vtp_vlan->index)));
+ 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;
- 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);
+ 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*((vtp_vlan->name_len + 3)/4);
- tptr += 4*((vtp_vlan->name_len + 3)/4);
+ len -= 4*((name_len + 3)/4);
+ tptr += 4*((name_len + 3)/4);
/* TLV information follows */
- while (len > 0) {
+ while (len != 0) {
/*
* 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
+ * 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 trunc;
- ND_TCHECK_2(tptr);
- type = *tptr;
- tlv_len = EXTRACT_U_1(tptr + 1);
+ goto invalid;
+ type = GET_U_1(tptr);
+ tlv_len = GET_U_1(tptr + 1);
- ND_PRINT((ndo, "\n\t\t%s (0x%04x) TLV",
+ ND_PRINT("\n\t\t%s (0x%04x) TLV",
tok2str(vtp_vlan_tlv_values, "Unknown", type),
- type));
+ type);
if (len < tlv_len * 2 + 2) {
- ND_PRINT((ndo, " (TLV goes past the end of the packet)"));
- return;
+ ND_PRINT(" (TLV goes past the end of the packet)");
+ goto invalid;
}
- ND_TCHECK2(*tptr, tlv_len * 2 +2);
+ 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((ndo, " (invalid TLV length %u != 1)", tlv_len));
- return;
+ ND_PRINT(" [TLV length %u != 1]", tlv_len);
+ goto invalid;
} else {
- tlv_value = EXTRACT_BE_U_2(tptr + 2);
+ tlv_value = GET_BE_U_2(tptr + 2);
switch (type) {
case VTP_VLAN_STE_HOP_COUNT:
- ND_PRINT((ndo, ", %u", tlv_value));
+ ND_PRINT(", %u", tlv_value);
break;
case VTP_VLAN_PRUNING:
- ND_PRINT((ndo, ", %s (%u)",
+ ND_PRINT(", %s (%u)",
tlv_value == 1 ? "Enabled" : "Disabled",
- tlv_value));
+ tlv_value);
break;
case VTP_VLAN_STP_TYPE:
- ND_PRINT((ndo, ", %s (%u)",
+ ND_PRINT(", %s (%u)",
tok2str(vtp_stp_type_values, "Unknown", tlv_value),
- tlv_value));
+ tlv_value);
break;
case VTP_VLAN_BRIDGE_TYPE:
- ND_PRINT((ndo, ", %s (%u)",
+ ND_PRINT(", %s (%u)",
tlv_value == 1 ? "SRB" : "SRT",
- tlv_value));
+ tlv_value);
break;
case VTP_VLAN_BACKUP_CRF_MODE:
- ND_PRINT((ndo, ", %s (%u)",
+ ND_PRINT(", %s (%u)",
tlv_value == 1 ? "Backup" : "Not backup",
- tlv_value));
+ tlv_value);
break;
/*
*
*/
- ND_TCHECK_4(tptr);
- ND_PRINT((ndo, "\n\tStart value: %u", EXTRACT_BE_U_4(tptr)));
+ ND_PRINT("\n\tStart value: %u", GET_BE_U_4(tptr));
break;
case VTP_JOIN_MESSAGE:
return;
- trunc:
- ND_PRINT((ndo, "[|vtp]"));
+invalid:
+ nd_print_invalid(ndo);
+tcheck_full_packet:
+ ND_TCHECK_LEN(pptr, length);
}
-
-/*
- * Local Variables:
- * c-style: whitesmith
- * c-basic-offset: 4
- * End:
- */
projects / tcpdump / blobdiff