/*
* Copyright (c) 2000 Lennert Buytenhek
*
* This software may be distributed either under the terms of the
* BSD-style license that accompanies tcpdump or the GNU General
* Public License
*
* Format and print IEEE 802.1d spanning tree protocol packets.
* Contributed by Lennert Buytenhek <buytenh@gnu.org>
*/
#ifndef lint
static const char rcsid[] _U_ =
"@(#) $Header: /tcpdump/master/tcpdump/print-stp.c,v 1.13.2.7 2007/03/18 17:12:36 hannes Exp $";
#endif
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <tcpdump-stdinc.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "interface.h"
#include "addrtoname.h"
#include "extract.h"
#define RSTP_EXTRACT_PORT_ROLE(x) (((x)&0x0C)>>2)
/* STP timers are expressed in multiples of 1/256th second */
#define STP_TIME_BASE 256
#define STP_BPDU_MSTP_MIN_LEN 102
struct stp_bpdu_ {
u_int8_t protocol_id[2];
u_int8_t protocol_version;
u_int8_t bpdu_type;
u_int8_t flags;
u_int8_t root_id[8];
u_int8_t root_path_cost[4];
u_int8_t bridge_id[8];
u_int8_t port_id[2];
u_int8_t message_age[2];
u_int8_t max_age[2];
u_int8_t hello_time[2];
u_int8_t forward_delay[2];
u_int8_t v1_length;
};
#define STP_PROTO_REGULAR 0x00
#define STP_PROTO_RAPID 0x02
#define STP_PROTO_MSTP 0x03
struct tok stp_proto_values[] = {
{ STP_PROTO_REGULAR, "802.1d" },
{ STP_PROTO_RAPID, "802.1w" },
{ STP_PROTO_MSTP, "802.1s" },
{ 0, NULL}
};
#define STP_BPDU_TYPE_CONFIG 0x00
#define STP_BPDU_TYPE_RSTP 0x02
#define STP_BPDU_TYPE_TOPO_CHANGE 0x80
struct tok stp_bpdu_flag_values[] = {
{ 0x01, "Topology change" },
{ 0x02, "Proposal" },
{ 0x10, "Learn" },
{ 0x20, "Forward" },
{ 0x40, "Agreement" },
{ 0x80, "Topology change ACK" },
{ 0, NULL}
};
struct tok stp_bpdu_type_values[] = {
{ STP_BPDU_TYPE_CONFIG, "Config" },
{ STP_BPDU_TYPE_RSTP, "Rapid STP" },
{ STP_BPDU_TYPE_TOPO_CHANGE, "Topology Change" },
{ 0, NULL}
};
struct tok rstp_obj_port_role_values[] = {
{ 0x00, "Unknown" },
{ 0x01, "Alternate" },
{ 0x02, "Root" },
{ 0x03, "Designated" },
{ 0, NULL}
};
static char *
stp_print_bridge_id(const u_char *p)
{
static char bridge_id_str[sizeof("pppp.aa:bb:cc:dd:ee:ff")];
snprintf(bridge_id_str, sizeof(bridge_id_str),
"%.2x%.2x.%.2x:%.2x:%.2x:%.2x:%.2x:%.2x",
p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]);
return bridge_id_str;
}
static void
stp_print_config_bpdu(const struct stp_bpdu_ *stp_bpdu, u_int length)
{
printf(", Flags [%s]",
bittok2str(stp_bpdu_flag_values, "none", stp_bpdu->flags));
printf(", bridge-id %s.%04x, length %u",
stp_print_bridge_id((const u_char *)&stp_bpdu->bridge_id),
EXTRACT_16BITS(&stp_bpdu->port_id), length);
/* in non-verbose mode just print the bridge-id */
if (!vflag) {
return;
}
printf("\n\tmessage-age %.2fs, max-age %.2fs"
", hello-time %.2fs, forwarding-delay %.2fs",
(float)EXTRACT_16BITS(&stp_bpdu->message_age) / STP_TIME_BASE,
(float)EXTRACT_16BITS(&stp_bpdu->max_age) / STP_TIME_BASE,
(float)EXTRACT_16BITS(&stp_bpdu->hello_time) / STP_TIME_BASE,
(float)EXTRACT_16BITS(&stp_bpdu->forward_delay) / STP_TIME_BASE);
printf("\n\troot-id %s, root-pathcost %u",
stp_print_bridge_id((const u_char *)&stp_bpdu->root_id),
EXTRACT_32BITS(&stp_bpdu->root_path_cost));
/* Port role is only valid for 802.1w */
if (stp_bpdu->protocol_version == STP_PROTO_RAPID) {
printf(", port-role %s",
tok2str(rstp_obj_port_role_values, "Unknown",
RSTP_EXTRACT_PORT_ROLE(stp_bpdu->flags)));
}
}
/*
* MSTP packet format
* Ref. IEEE 802.1Q 2003 Ed. Section 14
*
* MSTP BPDU
*
* 2 - bytes Protocol Id
* 1 - byte Protocol Ver.
* 1 - byte BPDU tye
* 1 - byte Flags
* 8 - bytes CIST Root Identifier
* 4 - bytes CIST External Path Cost
* 8 - bytes CIST Regional Root Identifier
* 2 - bytes CIST Port Identifier
* 2 - bytes Message Age
* 2 - bytes Max age
* 2 - bytes Hello Time
* 2 - bytes Forward delay
* 1 - byte Version 1 length. Must be 0
* 2 - bytes Version 3 length
* 1 - byte Config Identifier
* 32 - bytes Config Name
* 2 - bytes Revision level
* 16 - bytes Config Digest [MD5]
* 4 - bytes CIST Internal Root Path Cost
* 8 - bytes CIST Bridge Identifier
* 1 - byte CIST Remaining Hops
* 16 - bytes MSTI information [Max 64 MSTI, each 16 bytes]
*
* MSTI Payload
*
* 1 - byte MSTI flag
* 8 - bytes MSTI Regional Root Identifier
* 4 - bytes MSTI Regional Path Cost
* 1 - byte MSTI Bridge Priority
* 1 - byte MSTI Port Priority
* 1 - byte MSTI Remaining Hops
*/
#define MST_BPDU_MSTI_LENGTH 16
#define MST_BPDU_CONFIG_INFO_LENGTH 64
/* Offsets of fields from the begginning for the packet */
#define MST_BPDU_VER3_LEN_OFFSET 36
#define MST_BPDU_CONFIG_NAME_OFFSET 39
#define MST_BPDU_CONFIG_DIGEST_OFFSET 73
#define MST_BPDU_CIST_INT_PATH_COST_OFFSET 89
#define MST_BPDU_CIST_BRIDGE_ID_OFFSET 93
#define MST_BPDU_CIST_REMAIN_HOPS_OFFSET 101
#define MST_BPDU_MSTI_OFFSET 102
/* Offsets within an MSTI */
#define MST_BPDU_MSTI_ROOT_PRIO_OFFSET 1
#define MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET 9
#define MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET 13
#define MST_BPDU_MSTI_PORT_PRIO_OFFSET 14
#define MST_BPDU_MSTI_REMAIN_HOPS_OFFSET 15
static void
stp_print_mstp_bpdu(const struct stp_bpdu_ *stp_bpdu, u_int length)
{
const u_char *ptr;
u_int16_t v3len;
u_int16_t len;
u_int16_t msti;
u_int16_t offset;
ptr = (const u_char *)stp_bpdu;
printf(", CIST Flags [%s]",
bittok2str(stp_bpdu_flag_values, "none", stp_bpdu->flags));
/*
* in non-verbose mode just print the flags. We dont read that much
* of the packet (DEFAULT_SNAPLEN) to print out cist bridge-id
*/
if (!vflag) {
return;
}
printf(", CIST bridge-id %s.%04x, length %u",
stp_print_bridge_id(ptr + MST_BPDU_CIST_BRIDGE_ID_OFFSET),
EXTRACT_16BITS(&stp_bpdu->port_id), length);
printf("\n\tmessage-age %.2fs, max-age %.2fs"
", hello-time %.2fs, forwarding-delay %.2fs",
(float)EXTRACT_16BITS(&stp_bpdu->message_age) / STP_TIME_BASE,
(float)EXTRACT_16BITS(&stp_bpdu->max_age) / STP_TIME_BASE,
(float)EXTRACT_16BITS(&stp_bpdu->hello_time) / STP_TIME_BASE,
(float)EXTRACT_16BITS(&stp_bpdu->forward_delay) / STP_TIME_BASE);
printf("\n\tCIST root-id %s, ext-pathcost %u int-pathcost %u",
stp_print_bridge_id((const u_char *)&stp_bpdu->root_id),
EXTRACT_32BITS(&stp_bpdu->root_path_cost),
EXTRACT_32BITS(ptr + MST_BPDU_CIST_INT_PATH_COST_OFFSET));
printf(", port-role %s",
tok2str(rstp_obj_port_role_values, "Unknown",
RSTP_EXTRACT_PORT_ROLE(stp_bpdu->flags)));
printf("\n\tCIST regional-root-id %s",
stp_print_bridge_id((const u_char *)&stp_bpdu->bridge_id));
printf("\n\tMSTP Configuration Name %s, revision %u, digest %08x%08x%08x%08x",
ptr + MST_BPDU_CONFIG_NAME_OFFSET,
EXTRACT_16BITS(ptr + MST_BPDU_CONFIG_NAME_OFFSET + 32),
EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET),
EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 4),
EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 8),
EXTRACT_32BITS(ptr + MST_BPDU_CONFIG_DIGEST_OFFSET + 12));
printf("\n\tCIST remaining-hops %d", ptr[MST_BPDU_CIST_REMAIN_HOPS_OFFSET]);
/* Dump all MSTI's */
v3len = EXTRACT_16BITS(ptr + MST_BPDU_VER3_LEN_OFFSET);
if (v3len > MST_BPDU_CONFIG_INFO_LENGTH) {
len = v3len - MST_BPDU_CONFIG_INFO_LENGTH;
offset = MST_BPDU_MSTI_OFFSET;
while (len >= MST_BPDU_MSTI_LENGTH) {
msti = EXTRACT_16BITS(ptr + offset +
MST_BPDU_MSTI_ROOT_PRIO_OFFSET);
msti = msti & 0x0FFF;
printf("\n\tMSTI %d, Flags [%s], port-role %s",
msti, bittok2str(stp_bpdu_flag_values, "none", ptr[offset]),
tok2str(rstp_obj_port_role_values, "Unknown",
RSTP_EXTRACT_PORT_ROLE(ptr[offset])));
printf("\n\t\tMSTI regional-root-id %s, pathcost %u",
stp_print_bridge_id(ptr + offset +
MST_BPDU_MSTI_ROOT_PRIO_OFFSET),
EXTRACT_32BITS(ptr + offset +
MST_BPDU_MSTI_ROOT_PATH_COST_OFFSET));
printf("\n\t\tMSTI bridge-prio %d, port-prio %d, hops %d",
ptr[offset + MST_BPDU_MSTI_BRIDGE_PRIO_OFFSET] >> 4,
ptr[offset + MST_BPDU_MSTI_PORT_PRIO_OFFSET] >> 4,
ptr[offset + MST_BPDU_MSTI_REMAIN_HOPS_OFFSET]);
len -= MST_BPDU_MSTI_LENGTH;
offset += MST_BPDU_MSTI_LENGTH;
}
}
}
/*
* Print 802.1d / 802.1w / 802.1q (mstp) packets.
*/
void
stp_print(const u_char *p, u_int length)
{
const struct stp_bpdu_ *stp_bpdu;
u_int16_t mstp_len;
stp_bpdu = (struct stp_bpdu_*)p;
/* Minimum STP Frame size. */
if (length < 4)
goto trunc;
if (EXTRACT_16BITS(&stp_bpdu->protocol_id)) {
printf("unknown STP version, length %u", length);
return;
}
printf("STP %s", tok2str(stp_proto_values, "Unknown STP protocol (0x%02x)",
stp_bpdu->protocol_version));
switch (stp_bpdu->protocol_version) {
case STP_PROTO_REGULAR:
case STP_PROTO_RAPID:
case STP_PROTO_MSTP:
break;
default:
return;
}
printf(", %s", tok2str(stp_bpdu_type_values, "Unknown BPDU Type (0x%02x)",
stp_bpdu->bpdu_type));
switch (stp_bpdu->bpdu_type) {
case STP_BPDU_TYPE_CONFIG:
if (length < sizeof(struct stp_bpdu_) - 1) {
goto trunc;
}
stp_print_config_bpdu(stp_bpdu, length);
break;
case STP_BPDU_TYPE_RSTP:
if (stp_bpdu->protocol_version == STP_PROTO_RAPID) {
if (length < sizeof(struct stp_bpdu_)) {
goto trunc;
}
stp_print_config_bpdu(stp_bpdu, length);
} else if (stp_bpdu->protocol_version == STP_PROTO_MSTP) {
if (length < STP_BPDU_MSTP_MIN_LEN) {
goto trunc;
}
if (stp_bpdu->v1_length != 0) {
/* FIX ME: Emit a message here ? */
goto trunc;
}
/* Validate v3 length */
mstp_len = EXTRACT_16BITS(p + MST_BPDU_VER3_LEN_OFFSET);
mstp_len += 2; /* length encoding itself is 2 bytes */
if (length < (sizeof(struct stp_bpdu_) + mstp_len)) {
goto trunc;
}
stp_print_mstp_bpdu(stp_bpdu, length);
}
break;
case STP_BPDU_TYPE_TOPO_CHANGE:
/* always empty message - just break out */
break;
default:
break;
}
return;
trunc:
printf("[|stp %d]", length);
}
/*
* Local Variables:
* c-style: whitesmith
* c-basic-offset: 4
* End:
*/