freebsd-nq/contrib/tcpdump/print-l2tp.c

700 lines
19 KiB
C

/*
* Copyright (c) 1991, 1993, 1994, 1995, 1996, 1997
* The Regents of the University of California. All rights reserved.
*
* 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, (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, and (3) all advertising materials mentioning
* features or use of this software display the following acknowledgement:
* ``This product includes software developed by the University of California,
* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
* the University nor the names of its contributors may be used to endorse
* or promote products derived from this software without specific prior
* written permission.
* 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.
*
* L2TP support contributed by Motonori Shindo (mshindo@mshindo.net)
*/
#ifndef lint
static const char rcsid[] =
"@(#) $Header: /tcpdump/master/tcpdump/print-l2tp.c,v 1.10 2001/11/10 21:37:58 guy Exp $";
#endif
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdio.h>
#include <sys/types.h>
#include <sys/param.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "l2tp.h"
#include "interface.h"
static char tstr[] = " [|l2tp]";
#ifndef TRUE
#define TRUE 1
#endif
#ifndef FALSE
#define FALSE 0
#endif
#define L2TP_MSGTYPE_SCCRQ 1 /* Start-Control-Connection-Request */
#define L2TP_MSGTYPE_SCCRP 2 /* Start-Control-Connection-Reply */
#define L2TP_MSGTYPE_SCCCN 3 /* Start-Control-Connection-Connected */
#define L2TP_MSGTYPE_STOPCCN 4 /* Stop-Control-Connection-Notification */
#define L2TP_MSGTYPE_HELLO 6 /* Hello */
#define L2TP_MSGTYPE_OCRQ 7 /* Outgoing-Call-Request */
#define L2TP_MSGTYPE_OCRP 8 /* Outgoing-Call-Reply */
#define L2TP_MSGTYPE_OCCN 9 /* Outgoing-Call-Connected */
#define L2TP_MSGTYPE_ICRQ 10 /* Incoming-Call-Request */
#define L2TP_MSGTYPE_ICRP 11 /* Incoming-Call-Reply */
#define L2TP_MSGTYPE_ICCN 12 /* Incoming-Call-Connected */
#define L2TP_MSGTYPE_CDN 14 /* Call-Disconnect-Notify */
#define L2TP_MSGTYPE_WEN 15 /* WAN-Error-Notify */
#define L2TP_MSGTYPE_SLI 16 /* Set-Link-Info */
static struct tok l2tp_msgtype2str[] = {
{ L2TP_MSGTYPE_SCCRQ, "SCCRQ" },
{ L2TP_MSGTYPE_SCCRP, "SCCRP" },
{ L2TP_MSGTYPE_SCCCN, "SCCCN" },
{ L2TP_MSGTYPE_STOPCCN, "StopCCN" },
{ L2TP_MSGTYPE_HELLO, "HELLO" },
{ L2TP_MSGTYPE_OCRQ, "OCRQ" },
{ L2TP_MSGTYPE_OCRP, "OCRP" },
{ L2TP_MSGTYPE_OCCN, "OCCN" },
{ L2TP_MSGTYPE_ICRQ, "ICRQ" },
{ L2TP_MSGTYPE_ICRP, "ICRP" },
{ L2TP_MSGTYPE_ICCN, "ICCN" },
{ L2TP_MSGTYPE_CDN, "CDN" },
{ L2TP_MSGTYPE_WEN, "WEN" },
{ L2TP_MSGTYPE_SLI, "SLI" },
{ 0, NULL }
};
#define L2TP_AVP_MSGTYPE 0 /* Message Type */
#define L2TP_AVP_RESULT_CODE 1 /* Result Code */
#define L2TP_AVP_PROTO_VER 2 /* Protocol Version */
#define L2TP_AVP_FRAMING_CAP 3 /* Framing Capabilities */
#define L2TP_AVP_BEARER_CAP 4 /* Bearer Capabilities */
#define L2TP_AVP_TIE_BREAKER 5 /* Tie Breaker */
#define L2TP_AVP_FIRM_VER 6 /* Firmware Revision */
#define L2TP_AVP_HOST_NAME 7 /* Host Name */
#define L2TP_AVP_VENDOR_NAME 8 /* Vendor Name */
#define L2TP_AVP_ASSND_TUN_ID 9 /* Assigned Tunnel ID */
#define L2TP_AVP_RECV_WIN_SIZE 10 /* Receive Window Size */
#define L2TP_AVP_CHALLENGE 11 /* Challenge */
#define L2TP_AVP_Q931_CC 12 /* Q.931 Cause Code */
#define L2TP_AVP_CHALLENGE_RESP 13 /* Challenge Response */
#define L2TP_AVP_ASSND_SESS_ID 14 /* Assigned Session ID */
#define L2TP_AVP_CALL_SER_NUM 15 /* Call Serial Number */
#define L2TP_AVP_MINIMUM_BPS 16 /* Minimum BPS */
#define L2TP_AVP_MAXIMUM_BPS 17 /* Maximum BPS */
#define L2TP_AVP_BEARER_TYPE 18 /* Bearer Type */
#define L2TP_AVP_FRAMING_TYPE 19 /* Framing Type */
#define L2TP_AVP_PACKET_PROC_DELAY 20 /* Packet Processing Delay (OBSOLETE) */
#define L2TP_AVP_CALLED_NUMBER 21 /* Called Number */
#define L2TP_AVP_CALLING_NUMBER 22 /* Calling Number */
#define L2TP_AVP_SUB_ADDRESS 23 /* Sub-Address */
#define L2TP_AVP_TX_CONN_SPEED 24 /* (Tx) Connect Speed */
#define L2TP_AVP_PHY_CHANNEL_ID 25 /* Physical Channel ID */
#define L2TP_AVP_INI_RECV_LCP 26 /* Initial Received LCP CONFREQ */
#define L2TP_AVP_LAST_SENT_LCP 27 /* Last Sent LCP CONFREQ */
#define L2TP_AVP_LAST_RECV_LCP 28 /* Last Received LCP CONFREQ */
#define L2TP_AVP_PROXY_AUTH_TYPE 29 /* Proxy Authen Type */
#define L2TP_AVP_PROXY_AUTH_NAME 30 /* Proxy Authen Name */
#define L2TP_AVP_PROXY_AUTH_CHAL 31 /* Proxy Authen Challenge */
#define L2TP_AVP_PROXY_AUTH_ID 32 /* Proxy Authen ID */
#define L2TP_AVP_PROXY_AUTH_RESP 33 /* Proxy Authen Response */
#define L2TP_AVP_CALL_ERRORS 34 /* Call Errors */
#define L2TP_AVP_ACCM 35 /* ACCM */
#define L2TP_AVP_RANDOM_VECTOR 36 /* Random Vector */
#define L2TP_AVP_PRIVATE_GRP_ID 37 /* Private Group ID */
#define L2TP_AVP_RX_CONN_SPEED 38 /* (Rx) Connect Speed */
#define L2TP_AVP_SEQ_REQUIRED 39 /* Sequencing Required */
#define L2TP_AVP_PPP_DISCON_CC 46 /* PPP Disconnect Cause Code */
static struct tok l2tp_avp2str[] = {
{ L2TP_AVP_MSGTYPE, "MSGTYPE" },
{ L2TP_AVP_RESULT_CODE, "RESULT_CODE" },
{ L2TP_AVP_PROTO_VER, "PROTO_VER" },
{ L2TP_AVP_FRAMING_CAP, "FRAMING_CAP" },
{ L2TP_AVP_BEARER_CAP, "BEARER_CAP" },
{ L2TP_AVP_TIE_BREAKER, "TIE_BREAKER" },
{ L2TP_AVP_FIRM_VER, "FIRM_VER" },
{ L2TP_AVP_HOST_NAME, "HOST_NAME" },
{ L2TP_AVP_VENDOR_NAME, "VENDOR_NAME" },
{ L2TP_AVP_ASSND_TUN_ID, "ASSND_TUN_ID" },
{ L2TP_AVP_RECV_WIN_SIZE, "RECV_WIN_SIZE" },
{ L2TP_AVP_CHALLENGE, "CHALLENGE" },
{ L2TP_AVP_Q931_CC, "Q931_CC", },
{ L2TP_AVP_CHALLENGE_RESP, "CHALLENGE_RESP" },
{ L2TP_AVP_ASSND_SESS_ID, "ASSND_SESS_ID" },
{ L2TP_AVP_CALL_SER_NUM, "CALL_SER_NUM" },
{ L2TP_AVP_MINIMUM_BPS, "MINIMUM_BPS" },
{ L2TP_AVP_MAXIMUM_BPS, "MAXIMUM_BPS" },
{ L2TP_AVP_BEARER_TYPE, "BEARER_TYPE" },
{ L2TP_AVP_FRAMING_TYPE, "FRAMING_TYPE" },
{ L2TP_AVP_PACKET_PROC_DELAY, "PACKET_PROC_DELAY" },
{ L2TP_AVP_CALLED_NUMBER, "CALLED_NUMBER" },
{ L2TP_AVP_CALLING_NUMBER, "CALLING_NUMBER" },
{ L2TP_AVP_SUB_ADDRESS, "SUB_ADDRESS" },
{ L2TP_AVP_TX_CONN_SPEED, "TX_CONN_SPEED" },
{ L2TP_AVP_PHY_CHANNEL_ID, "PHY_CHANNEL_ID" },
{ L2TP_AVP_INI_RECV_LCP, "INI_RECV_LCP" },
{ L2TP_AVP_LAST_SENT_LCP, "LAST_SENT_LCP" },
{ L2TP_AVP_LAST_RECV_LCP, "LAST_RECV_LCP" },
{ L2TP_AVP_PROXY_AUTH_TYPE, "PROXY_AUTH_TYPE" },
{ L2TP_AVP_PROXY_AUTH_NAME, "PROXY_AUTH_NAME" },
{ L2TP_AVP_PROXY_AUTH_CHAL, "PROXY_AUTH_CHAL" },
{ L2TP_AVP_PROXY_AUTH_ID, "PROXY_AUTH_ID" },
{ L2TP_AVP_PROXY_AUTH_RESP, "PROXY_AUTH_RESP" },
{ L2TP_AVP_CALL_ERRORS, "CALL_ERRORS" },
{ L2TP_AVP_ACCM, "ACCM" },
{ L2TP_AVP_RANDOM_VECTOR, "RANDOM_VECTOR" },
{ L2TP_AVP_PRIVATE_GRP_ID, "PRIVATE_GRP_ID" },
{ L2TP_AVP_RX_CONN_SPEED, "RX_CONN_SPEED" },
{ L2TP_AVP_SEQ_REQUIRED, "SEQ_REQUIRED" },
{ L2TP_AVP_PPP_DISCON_CC, "PPP_DISCON_CC" },
{ 0, NULL }
};
static struct tok l2tp_authentype2str[] = {
{ L2TP_AUTHEN_TYPE_RESERVED, "Reserved" },
{ L2TP_AUTHEN_TYPE_TEXTUAL, "Textual" },
{ L2TP_AUTHEN_TYPE_CHAP, "CHAP" },
{ L2TP_AUTHEN_TYPE_PAP, "PAP" },
{ L2TP_AUTHEN_TYPE_NO_AUTH, "No Auth" },
{ L2TP_AUTHEN_TYPE_MSCHAPv1, "MS-CHAPv1" },
{ 0, NULL }
};
#define L2TP_PPP_DISCON_CC_DIRECTION_GLOBAL 0
#define L2TP_PPP_DISCON_CC_DIRECTION_AT_PEER 1
#define L2TP_PPP_DISCON_CC_DIRECTION_AT_LOCAL 2
static struct tok l2tp_cc_direction2str[] = {
{ L2TP_PPP_DISCON_CC_DIRECTION_GLOBAL, "global error" },
{ L2TP_PPP_DISCON_CC_DIRECTION_AT_PEER, "at peer" },
{ L2TP_PPP_DISCON_CC_DIRECTION_AT_LOCAL,"at local" },
{ 0, NULL }
};
#if 0
static char *l2tp_result_code_StopCCN[] = {
"Reserved",
"General request to clear control connection",
"General error--Error Code indicates the problem",
"Control channel already exists",
"Requester is not authorized to establish a control channel",
"The protocol version of the requester is not supported",
"Requester is being shut down",
"Finite State Machine error"
#define L2TP_MAX_RESULT_CODE_STOPCC_INDEX 8
};
#endif
#if 0
static char *l2tp_result_code_CDN[] = {
"Reserved",
"Call disconnected due to loss of carrier",
"Call disconnected for the reason indicated in error code",
"Call disconnected for administrative reasons",
"Call failed due to lack of appropriate facilities being " \
"available (temporary condition)",
"Call failed due to lack of appropriate facilities being " \
"available (permanent condition)",
"Invalid destination",
"Call failed due to no carrier detected",
"Call failed due to detection of a busy signal",
"Call failed due to lack of a dial tone",
"Call was not established within time allotted by LAC",
"Call was connected but no appropriate framing was detected"
#define L2TP_MAX_RESULT_CODE_CDN_INDEX 12
};
#endif
#if 0
static char *l2tp_error_code_general[] = {
"No general error",
"No control connection exists yet for this LAC-LNS pair",
"Length is wrong",
"One of the field values was out of range or " \
"reserved field was non-zero"
"Insufficient resources to handle this operation now",
"The Session ID is invalid in this context",
"A generic vendor-specific error occurred in the LAC",
"Try another"
#define L2TP_MAX_ERROR_CODE_GENERAL_INDEX 8
};
#endif
/******************************/
/* generic print out routines */
/******************************/
static void
print_string(const u_char *dat, u_int length)
{
int i;
for (i=0; i<length; i++) {
printf("%c", *dat++);
}
}
static void
print_octets(const u_char *dat, u_int length)
{
int i;
for (i=0; i<length; i++) {
printf("%02x", *dat++);
}
}
static void
print_16bits_val(const u_int16_t *dat)
{
printf("%u", ntohs(*dat));
}
static void
print_32bits_val(const u_int32_t *dat)
{
printf("%lu", (u_long)ntohl(*dat));
}
/***********************************/
/* AVP-specific print out routines */
/***********************************/
static void
l2tp_msgtype_print(const u_char *dat)
{
u_int16_t *ptr = (u_int16_t*)dat;
printf("%s", tok2str(l2tp_msgtype2str, "MSGTYPE-#%u", ntohs(*ptr)));
}
static void
l2tp_result_code_print(const u_char *dat, u_int length)
{
u_int16_t *ptr = (u_int16_t *)dat;
printf("%u", ntohs(*ptr++)); /* Result Code */
if (length > 2) { /* Error Code (opt) */
printf("/%u", ntohs(*ptr++));
}
if (length > 4) { /* Error Message (opt) */
printf(" ");
print_string((u_char *)ptr, length - 4);
}
}
static void
l2tp_proto_ver_print(const u_int16_t *dat)
{
printf("%u.%u", (ntohs(*dat) >> 8), (ntohs(*dat) & 0xff));
}
static void
l2tp_framing_cap_print(const u_char *dat)
{
u_int32_t *ptr = (u_int32_t *)dat;
if (ntohl(*ptr) & L2TP_FRAMING_CAP_ASYNC_MASK) {
printf("A");
}
if (ntohl(*ptr) & L2TP_FRAMING_CAP_SYNC_MASK) {
printf("S");
}
}
static void
l2tp_bearer_cap_print(const u_char *dat)
{
u_int32_t *ptr = (u_int32_t *)dat;
if (ntohl(*ptr) & L2TP_BEARER_CAP_ANALOG_MASK) {
printf("A");
}
if (ntohl(*ptr) & L2TP_BEARER_CAP_DIGITAL_MASK) {
printf("D");
}
}
static void
l2tp_q931_cc_print(const u_char *dat, u_int length)
{
print_16bits_val((u_int16_t *)dat);
printf(", %02x", dat[2]);
if (length > 3) {
printf(" ");
print_string(dat+3, length-3);
}
}
static void
l2tp_bearer_type_print(const u_char *dat)
{
u_int32_t *ptr = (u_int32_t *)dat;
if (ntohl(*ptr) & L2TP_BEARER_TYPE_ANALOG_MASK) {
printf("A");
}
if (ntohl(*ptr) & L2TP_BEARER_TYPE_DIGITAL_MASK) {
printf("D");
}
}
static void
l2tp_framing_type_print(const u_char *dat)
{
u_int32_t *ptr = (u_int32_t *)dat;
if (ntohl(*ptr) & L2TP_FRAMING_TYPE_ASYNC_MASK) {
printf("A");
}
if (ntohl(*ptr) & L2TP_FRAMING_TYPE_SYNC_MASK) {
printf("S");
}
}
static void
l2tp_packet_proc_delay_print(void)
{
printf("obsolete");
}
static void
l2tp_proxy_auth_type_print(const u_char *dat)
{
u_int16_t *ptr = (u_int16_t *)dat;
printf("%s", tok2str(l2tp_authentype2str,
"AuthType-#%u", ntohs(*ptr)));
}
static void
l2tp_proxy_auth_id_print(const u_char *dat)
{
u_int16_t *ptr = (u_int16_t *)dat;
printf("%u", ntohs(*ptr) & L2TP_PROXY_AUTH_ID_MASK);
}
static void
l2tp_call_errors_print(const u_char *dat)
{
u_int16_t *ptr = (u_int16_t *)dat;
u_int16_t val_h, val_l;
ptr++; /* skip "Reserved" */
val_h = ntohs(*ptr++);
val_l = ntohs(*ptr++);
printf("CRCErr=%u ", (val_h<<16) + val_l);
val_h = ntohs(*ptr++);
val_l = ntohs(*ptr++);
printf("FrameErr=%u ", (val_h<<16) + val_l);
val_h = ntohs(*ptr++);
val_l = ntohs(*ptr++);
printf("HardOver=%u ", (val_h<<16) + val_l);
val_h = ntohs(*ptr++);
val_l = ntohs(*ptr++);
printf("BufOver=%u ", (val_h<<16) + val_l);
val_h = ntohs(*ptr++);
val_l = ntohs(*ptr++);
printf("Timeout=%u ", (val_h<<16) + val_l);
val_h = ntohs(*ptr++);
val_l = ntohs(*ptr++);
printf("AlignErr=%u ", (val_h<<16) + val_l);
}
static void
l2tp_accm_print(const u_char *dat)
{
u_int16_t *ptr = (u_int16_t *)dat;
u_int16_t val_h, val_l;
ptr++; /* skip "Reserved" */
val_h = ntohs(*ptr++);
val_l = ntohs(*ptr++);
printf("send=%08x ", (val_h<<16) + val_l);
val_h = ntohs(*ptr++);
val_l = ntohs(*ptr++);
printf("recv=%08x ", (val_h<<16) + val_l);
}
static void
l2tp_ppp_discon_cc_print(const u_char *dat, u_int length)
{
u_int16_t *ptr = (u_int16_t *)dat;
printf("%04x, ", ntohs(*ptr++)); /* Disconnect Code */
printf("%04x ", ntohs(*ptr++)); /* Control Protocol Number */
printf("%s", tok2str(l2tp_cc_direction2str,
"Direction-#%u", *((u_char *)ptr++)));
if (length > 5) {
printf(" ");
print_string((const u_char *)ptr, length-5);
}
}
static void
l2tp_avp_print(const u_char *dat, int length)
{
u_int len;
const u_int16_t *ptr = (u_int16_t *)dat;
u_int16_t attr_type;
int hidden = FALSE;
if (length <= 0) {
return;
}
printf(" ");
TCHECK(*ptr); /* Flags & Length */
len = ntohs(*ptr) & L2TP_AVP_HDR_LEN_MASK;
/* If it is not long enough to decode the entire AVP, we'll
abandon. */
TCHECK2(*ptr, len);
/* After this point, no need to worry about truncation */
if (ntohs(*ptr) & L2TP_AVP_HDR_FLAG_MANDATORY) {
printf("*");
}
if (ntohs(*ptr) & L2TP_AVP_HDR_FLAG_HIDDEN) {
hidden = TRUE;
printf("?");
}
ptr++;
if (ntohs(*ptr)) {
/* Vendor Specific Attribute */
printf("VENDOR%04x:", ntohs(*ptr++));
printf("ATTR%04x", ntohs(*ptr++));
printf("(");
print_octets((u_char *)ptr, len-6);
printf(")");
} else {
/* IETF-defined Attributes */
ptr++;
attr_type = ntohs(*ptr++);
printf("%s", tok2str(l2tp_avp2str, "AVP-#%u", attr_type));
printf("(");
if (hidden) {
printf("???");
} else {
switch (attr_type) {
case L2TP_AVP_MSGTYPE:
l2tp_msgtype_print((u_char *)ptr);
break;
case L2TP_AVP_RESULT_CODE:
l2tp_result_code_print((u_char *)ptr, len-6);
break;
case L2TP_AVP_PROTO_VER:
l2tp_proto_ver_print(ptr);
break;
case L2TP_AVP_FRAMING_CAP:
l2tp_framing_cap_print((u_char *)ptr);
break;
case L2TP_AVP_BEARER_CAP:
l2tp_bearer_cap_print((u_char *)ptr);
break;
case L2TP_AVP_TIE_BREAKER:
print_octets((u_char *)ptr, 8);
break;
case L2TP_AVP_FIRM_VER:
case L2TP_AVP_ASSND_TUN_ID:
case L2TP_AVP_RECV_WIN_SIZE:
case L2TP_AVP_ASSND_SESS_ID:
print_16bits_val(ptr);
break;
case L2TP_AVP_HOST_NAME:
case L2TP_AVP_VENDOR_NAME:
case L2TP_AVP_CALLING_NUMBER:
case L2TP_AVP_CALLED_NUMBER:
case L2TP_AVP_SUB_ADDRESS:
case L2TP_AVP_PROXY_AUTH_NAME:
case L2TP_AVP_PRIVATE_GRP_ID:
print_string((u_char *)ptr, len-6);
break;
case L2TP_AVP_CHALLENGE:
case L2TP_AVP_INI_RECV_LCP:
case L2TP_AVP_LAST_SENT_LCP:
case L2TP_AVP_LAST_RECV_LCP:
case L2TP_AVP_PROXY_AUTH_CHAL:
case L2TP_AVP_PROXY_AUTH_RESP:
case L2TP_AVP_RANDOM_VECTOR:
print_octets((u_char *)ptr, len-6);
break;
case L2TP_AVP_Q931_CC:
l2tp_q931_cc_print((u_char *)ptr, len-6);
break;
case L2TP_AVP_CHALLENGE_RESP:
print_octets((u_char *)ptr, 16);
break;
case L2TP_AVP_CALL_SER_NUM:
case L2TP_AVP_MINIMUM_BPS:
case L2TP_AVP_MAXIMUM_BPS:
case L2TP_AVP_TX_CONN_SPEED:
case L2TP_AVP_PHY_CHANNEL_ID:
case L2TP_AVP_RX_CONN_SPEED:
print_32bits_val((u_int32_t *)ptr);
break;
case L2TP_AVP_BEARER_TYPE:
l2tp_bearer_type_print((u_char *)ptr);
break;
case L2TP_AVP_FRAMING_TYPE:
l2tp_framing_type_print((u_char *)ptr);
break;
case L2TP_AVP_PACKET_PROC_DELAY:
l2tp_packet_proc_delay_print();
break;
case L2TP_AVP_PROXY_AUTH_TYPE:
l2tp_proxy_auth_type_print((u_char *)ptr);
break;
case L2TP_AVP_PROXY_AUTH_ID:
l2tp_proxy_auth_id_print((u_char *)ptr);
break;
case L2TP_AVP_CALL_ERRORS:
l2tp_call_errors_print((u_char *)ptr);
break;
case L2TP_AVP_ACCM:
l2tp_accm_print((u_char *)ptr);
break;
case L2TP_AVP_SEQ_REQUIRED:
break; /* No Attribute Value */
case L2TP_AVP_PPP_DISCON_CC:
l2tp_ppp_discon_cc_print((u_char *)ptr, len-6);
break;
default:
break;
}
}
printf(")");
}
l2tp_avp_print(dat+len, length-len);
return;
trunc:
printf("|...");
}
void
l2tp_print(const u_char *dat, u_int length)
{
const u_int16_t *ptr = (u_int16_t *)dat;
u_int cnt = 0; /* total octets consumed */
u_int16_t pad;
int flag_t, flag_l, flag_s, flag_o, flag_p;
u_int16_t l2tp_len;
flag_t = flag_l = flag_s = flag_o = flag_p = FALSE;
TCHECK(*ptr); /* Flags & Version */
if ((ntohs(*ptr) & L2TP_VERSION_MASK) == L2TP_VERSION_L2TP) {
printf(" l2tp:");
} else if ((ntohs(*ptr) & L2TP_VERSION_MASK) == L2TP_VERSION_L2F) {
printf(" l2f:");
return; /* nothing to do */
} else {
printf(" Unknown Version, neither L2F(1) nor L2TP(2)");
return; /* nothing we can do */
}
printf("[");
if (ntohs(*ptr) & L2TP_FLAG_TYPE) {
flag_t = TRUE;
printf("T");
}
if (ntohs(*ptr) & L2TP_FLAG_LENGTH) {
flag_l = TRUE;
printf("L");
}
if (ntohs(*ptr) & L2TP_FLAG_SEQUENCE) {
flag_s = TRUE;
printf("S");
}
if (ntohs(*ptr) & L2TP_FLAG_OFFSET) {
flag_o = TRUE;
printf("O");
}
if (ntohs(*ptr) & L2TP_FLAG_PRIORITY) {
flag_p = TRUE;
printf("P");
}
printf("]");
ptr++;
cnt += 2;
if (flag_l) {
TCHECK(*ptr); /* Length */
l2tp_len = ntohs(*ptr++);
cnt += 2;
} else {
l2tp_len = 0;
}
TCHECK(*ptr); /* Tunnel ID */
printf("(%u/", ntohs(*ptr++));
cnt += 2;
TCHECK(*ptr); /* Session ID */
printf("%u)", ntohs(*ptr++));
cnt += 2;
if (flag_s) {
TCHECK(*ptr); /* Ns */
printf("Ns=%u,", ntohs(*ptr++));
cnt += 2;
TCHECK(*ptr); /* Nr */
printf("Nr=%u", ntohs(*ptr++));
cnt += 2;
}
if (flag_o) {
TCHECK(*ptr); /* Offset Size */
pad = ntohs(*ptr++);
ptr += pad / sizeof(*ptr);
cnt += (2 + pad);
}
if (flag_t) {
if (length - cnt == 0) {
printf(" ZLB");
} else {
l2tp_avp_print((u_char *)ptr, length - cnt);
}
} else {
printf(" {");
ppp_print((u_char *)ptr, length - cnt);
printf("}");
}
return;
trunc:
printf("%s", tstr);
}