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mirror of https://git.FreeBSD.org/src.git synced 2024-12-22 11:17:19 +00:00
freebsd/contrib/tcpdump/print-ldp.c
2009-03-21 18:30:25 +00:00

624 lines
21 KiB
C

/*
* 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.
*
* Original code by Hannes Gredler (hannes@juniper.net)
* and Steinar Haug (sthaug@nethelp.no)
*/
#ifndef lint
static const char rcsid[] _U_ =
"@(#) $Header: /tcpdump/master/tcpdump/print-ldp.c,v 1.20 2006-06-23 02:03:09 hannes Exp $";
#endif
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <tcpdump-stdinc.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "interface.h"
#include "decode_prefix.h"
#include "extract.h"
#include "addrtoname.h"
#include "l2vpn.h"
#include "af.h"
/*
* ldp common header
*
* 0 1 2 3
* 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 | PDU Length |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | LDP Identifier |
* + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
*/
struct ldp_common_header {
u_int8_t version[2];
u_int8_t pdu_length[2];
u_int8_t lsr_id[4];
u_int8_t label_space[2];
};
#define LDP_VERSION 1
/*
* ldp message header
*
* 0 1 2 3
* 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
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |U| Message Type | Message Length |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Message ID |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | |
* + +
* | Mandatory Parameters |
* + +
* | |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | |
* + +
* | Optional Parameters |
* + +
* | |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
struct ldp_msg_header {
u_int8_t type[2];
u_int8_t length[2];
u_int8_t id[4];
};
#define LDP_MASK_MSG_TYPE(x) ((x)&0x7fff)
#define LDP_MASK_U_BIT(x) ((x)&0x8000)
#define LDP_MSG_NOTIF 0x0001
#define LDP_MSG_HELLO 0x0100
#define LDP_MSG_INIT 0x0200
#define LDP_MSG_KEEPALIVE 0x0201
#define LDP_MSG_ADDRESS 0x0300
#define LDP_MSG_ADDRESS_WITHDRAW 0x0301
#define LDP_MSG_LABEL_MAPPING 0x0400
#define LDP_MSG_LABEL_REQUEST 0x0401
#define LDP_MSG_LABEL_WITHDRAW 0x0402
#define LDP_MSG_LABEL_RELEASE 0x0403
#define LDP_MSG_LABEL_ABORT_REQUEST 0x0404
#define LDP_VENDOR_PRIVATE_MIN 0x3e00
#define LDP_VENDOR_PRIVATE_MAX 0x3eff
#define LDP_EXPERIMENTAL_MIN 0x3f00
#define LDP_EXPERIMENTAL_MAX 0x3fff
static const struct tok ldp_msg_values[] = {
{ LDP_MSG_NOTIF, "Notification" },
{ LDP_MSG_HELLO, "Hello" },
{ LDP_MSG_INIT, "Initialization" },
{ LDP_MSG_KEEPALIVE, "Keepalive" },
{ LDP_MSG_ADDRESS, "Address" },
{ LDP_MSG_ADDRESS_WITHDRAW, "Address Withdraw" },
{ LDP_MSG_LABEL_MAPPING, "Label Mapping" },
{ LDP_MSG_LABEL_REQUEST, "Label Request" },
{ LDP_MSG_LABEL_WITHDRAW, "Label Withdraw" },
{ LDP_MSG_LABEL_RELEASE, "Label Release" },
{ LDP_MSG_LABEL_ABORT_REQUEST, "Label Abort Request" },
{ 0, NULL}
};
#define LDP_MASK_TLV_TYPE(x) ((x)&0x3fff)
#define LDP_MASK_F_BIT(x) ((x)&0x4000)
#define LDP_TLV_FEC 0x0100
#define LDP_TLV_ADDRESS_LIST 0x0101
#define LDP_TLV_ADDRESS_LIST_AFNUM_LEN 2
#define LDP_TLV_HOP_COUNT 0x0103
#define LDP_TLV_PATH_VECTOR 0x0104
#define LDP_TLV_GENERIC_LABEL 0x0200
#define LDP_TLV_ATM_LABEL 0x0201
#define LDP_TLV_FR_LABEL 0x0202
#define LDP_TLV_STATUS 0x0300
#define LDP_TLV_EXTD_STATUS 0x0301
#define LDP_TLV_RETURNED_PDU 0x0302
#define LDP_TLV_RETURNED_MSG 0x0303
#define LDP_TLV_COMMON_HELLO 0x0400
#define LDP_TLV_IPV4_TRANSPORT_ADDR 0x0401
#define LDP_TLV_CONFIG_SEQ_NUMBER 0x0402
#define LDP_TLV_IPV6_TRANSPORT_ADDR 0x0403
#define LDP_TLV_COMMON_SESSION 0x0500
#define LDP_TLV_ATM_SESSION_PARM 0x0501
#define LDP_TLV_FR_SESSION_PARM 0x0502
#define LDP_TLV_FT_SESSION 0x0503
#define LDP_TLV_LABEL_REQUEST_MSG_ID 0x0600
#define LDP_TLV_MTU 0x0601 /* rfc 3988 */
static const struct tok ldp_tlv_values[] = {
{ LDP_TLV_FEC, "FEC" },
{ LDP_TLV_ADDRESS_LIST, "Address List" },
{ LDP_TLV_HOP_COUNT, "Hop Count" },
{ LDP_TLV_PATH_VECTOR, "Path Vector" },
{ LDP_TLV_GENERIC_LABEL, "Generic Label" },
{ LDP_TLV_ATM_LABEL, "ATM Label" },
{ LDP_TLV_FR_LABEL, "Frame-Relay Label" },
{ LDP_TLV_STATUS, "Status" },
{ LDP_TLV_EXTD_STATUS, "Extended Status" },
{ LDP_TLV_RETURNED_PDU, "Returned PDU" },
{ LDP_TLV_RETURNED_MSG, "Returned Message" },
{ LDP_TLV_COMMON_HELLO, "Common Hello Parameters" },
{ LDP_TLV_IPV4_TRANSPORT_ADDR, "IPv4 Transport Address" },
{ LDP_TLV_CONFIG_SEQ_NUMBER, "Configuration Sequence Number" },
{ LDP_TLV_IPV6_TRANSPORT_ADDR, "IPv6 Transport Address" },
{ LDP_TLV_COMMON_SESSION, "Common Session Parameters" },
{ LDP_TLV_ATM_SESSION_PARM, "ATM Session Parameters" },
{ LDP_TLV_FR_SESSION_PARM, "Frame-Relay Session Parameters" },
{ LDP_TLV_FT_SESSION, "Fault-Tolerant Session Parameters" },
{ LDP_TLV_LABEL_REQUEST_MSG_ID, "Label Request Message ID" },
{ LDP_TLV_MTU, "MTU" },
{ 0, NULL}
};
#define LDP_FEC_WILDCARD 0x01
#define LDP_FEC_PREFIX 0x02
#define LDP_FEC_HOSTADDRESS 0x03
/* From draft-martini-l2circuit-trans-mpls-13.txt */
#define LDP_FEC_MARTINI_VC 0x80
static const struct tok ldp_fec_values[] = {
{ LDP_FEC_WILDCARD, "Wildcard" },
{ LDP_FEC_PREFIX, "Prefix" },
{ LDP_FEC_HOSTADDRESS, "Host address" },
{ LDP_FEC_MARTINI_VC, "Martini VC" },
{ 0, NULL}
};
#define LDP_FEC_MARTINI_IFPARM_MTU 0x01
#define LDP_FEC_MARTINI_IFPARM_DESC 0x03
#define LDP_FEC_MARTINI_IFPARM_VCCV 0x0c
static const struct tok ldp_fec_martini_ifparm_values[] = {
{ LDP_FEC_MARTINI_IFPARM_MTU, "MTU" },
{ LDP_FEC_MARTINI_IFPARM_DESC, "Description" },
{ LDP_FEC_MARTINI_IFPARM_VCCV, "VCCV" },
{ 0, NULL}
};
/* draft-ietf-pwe3-vccv-04.txt */
static const struct tok ldp_fec_martini_ifparm_vccv_cc_values[] = {
{ 0x01, "PWE3 control word" },
{ 0x02, "MPLS Router Alert Label" },
{ 0x04, "MPLS inner label TTL = 1" },
{ 0, NULL}
};
/* draft-ietf-pwe3-vccv-04.txt */
static const struct tok ldp_fec_martini_ifparm_vccv_cv_values[] = {
{ 0x01, "ICMP Ping" },
{ 0x02, "LSP Ping" },
{ 0x04, "BFD" },
{ 0, NULL}
};
int ldp_msg_print(register const u_char *);
int ldp_tlv_print(register const u_char *);
/*
* ldp tlv header
*
* 0 1 2 3
* 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
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |U|F| Type | Length |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | |
* | Value |
* ~ ~
* | |
* | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
int
ldp_tlv_print(register const u_char *tptr) {
struct ldp_tlv_header {
u_int8_t type[2];
u_int8_t length[2];
};
const struct ldp_tlv_header *ldp_tlv_header;
u_short tlv_type,tlv_len,tlv_tlen,af,ft_flags;
u_char fec_type;
u_int ui,vc_info_len, vc_info_tlv_type, vc_info_tlv_len,idx;
char buf[100];
int i;
ldp_tlv_header = (const struct ldp_tlv_header *)tptr;
tlv_len=EXTRACT_16BITS(ldp_tlv_header->length);
tlv_tlen=tlv_len;
tlv_type=LDP_MASK_TLV_TYPE(EXTRACT_16BITS(ldp_tlv_header->type));
/* FIXME vendor private / experimental check */
printf("\n\t %s TLV (0x%04x), length: %u, Flags: [%s and %s forward if unknown]",
tok2str(ldp_tlv_values,
"Unknown",
tlv_type),
tlv_type,
tlv_len,
LDP_MASK_U_BIT(EXTRACT_16BITS(&ldp_tlv_header->type)) ? "continue processing" : "ignore",
LDP_MASK_F_BIT(EXTRACT_16BITS(&ldp_tlv_header->type)) ? "do" : "don't");
tptr+=sizeof(struct ldp_tlv_header);
switch(tlv_type) {
case LDP_TLV_COMMON_HELLO:
printf("\n\t Hold Time: %us, Flags: [%s Hello%s]",
EXTRACT_16BITS(tptr),
(EXTRACT_16BITS(tptr+2)&0x8000) ? "Targeted" : "Link",
(EXTRACT_16BITS(tptr+2)&0x4000) ? ", Request for targeted Hellos" : "");
break;
case LDP_TLV_IPV4_TRANSPORT_ADDR:
printf("\n\t IPv4 Transport Address: %s", ipaddr_string(tptr));
break;
#ifdef INET6
case LDP_TLV_IPV6_TRANSPORT_ADDR:
printf("\n\t IPv6 Transport Address: %s", ip6addr_string(tptr));
break;
#endif
case LDP_TLV_CONFIG_SEQ_NUMBER:
printf("\n\t Sequence Number: %u", EXTRACT_32BITS(tptr));
break;
case LDP_TLV_ADDRESS_LIST:
af = EXTRACT_16BITS(tptr);
tptr+=LDP_TLV_ADDRESS_LIST_AFNUM_LEN;
tlv_tlen -= LDP_TLV_ADDRESS_LIST_AFNUM_LEN;
printf("\n\t Address Family: %s, addresses",
tok2str(af_values, "Unknown (%u)", af));
switch (af) {
case AFNUM_INET:
while(tlv_tlen >= sizeof(struct in_addr)) {
printf(" %s",ipaddr_string(tptr));
tlv_tlen-=sizeof(struct in_addr);
tptr+=sizeof(struct in_addr);
}
break;
#ifdef INET6
case AFNUM_INET6:
while(tlv_tlen >= sizeof(struct in6_addr)) {
printf(" %s",ip6addr_string(tptr));
tlv_tlen-=sizeof(struct in6_addr);
tptr+=sizeof(struct in6_addr);
}
break;
#endif
default:
/* unknown AF */
break;
}
break;
case LDP_TLV_COMMON_SESSION:
printf("\n\t Version: %u, Keepalive: %us, Flags: [Downstream %s, Loop Detection %s]",
EXTRACT_16BITS(tptr), EXTRACT_16BITS(tptr+2),
(EXTRACT_16BITS(tptr+6)&0x8000) ? "On Demand" : "Unsolicited",
(EXTRACT_16BITS(tptr+6)&0x4000) ? "Enabled" : "Disabled"
);
break;
case LDP_TLV_FEC:
fec_type = *tptr;
printf("\n\t %s FEC (0x%02x)",
tok2str(ldp_fec_values, "Unknown", fec_type),
fec_type);
tptr+=1;
switch(fec_type) {
case LDP_FEC_WILDCARD:
break;
case LDP_FEC_PREFIX:
af = EXTRACT_16BITS(tptr);
tptr+=2;
if (af == AFNUM_INET) {
i=decode_prefix4(tptr,buf,sizeof(buf));
printf(": IPv4 prefix %s",buf);
}
#ifdef INET6
else if (af == AFNUM_INET6) {
i=decode_prefix6(tptr,buf,sizeof(buf));
printf(": IPv6 prefix %s",buf);
}
#endif
break;
case LDP_FEC_HOSTADDRESS:
break;
case LDP_FEC_MARTINI_VC:
if (!TTEST2(*tptr, 11))
goto trunc;
vc_info_len = *(tptr+2);
printf(": %s, %scontrol word, group-ID %u, VC-ID %u, VC-info-length: %u",
tok2str(l2vpn_encaps_values, "Unknown", EXTRACT_16BITS(tptr)&0x7fff),
EXTRACT_16BITS(tptr)&0x8000 ? "" : "no ",
EXTRACT_32BITS(tptr+3),
EXTRACT_32BITS(tptr+7),
vc_info_len);
if (vc_info_len == 0) /* infinite loop protection */
break;
tptr+=11;
if (!TTEST2(*tptr, vc_info_len))
goto trunc;
while (vc_info_len > 2) {
vc_info_tlv_type = *tptr;
vc_info_tlv_len = *(tptr+1);
if (vc_info_tlv_len < 2)
break;
if (vc_info_len < vc_info_tlv_len)
break;
printf("\n\t\tInterface Parameter: %s (0x%02x), len %u",
tok2str(ldp_fec_martini_ifparm_values,"Unknown",vc_info_tlv_type),
vc_info_tlv_type,
vc_info_tlv_len);
switch(vc_info_tlv_type) {
case LDP_FEC_MARTINI_IFPARM_MTU:
printf(": %u",EXTRACT_16BITS(tptr+2));
break;
case LDP_FEC_MARTINI_IFPARM_DESC:
printf(": ");
for (idx = 2; idx < vc_info_tlv_len; idx++)
safeputchar(*(tptr+idx));
break;
case LDP_FEC_MARTINI_IFPARM_VCCV:
printf("\n\t\t Control Channels (0x%02x) = [%s]",
*(tptr+2),
bittok2str(ldp_fec_martini_ifparm_vccv_cc_values,"none",*(tptr+2)));
printf("\n\t\t CV Types (0x%02x) = [%s]",
*(tptr+3),
bittok2str(ldp_fec_martini_ifparm_vccv_cv_values,"none",*(tptr+3)));
break;
default:
print_unknown_data(tptr+2,"\n\t\t ",vc_info_tlv_len-2);
break;
}
vc_info_len -= vc_info_tlv_len;
tptr += vc_info_tlv_len;
}
break;
}
break;
case LDP_TLV_GENERIC_LABEL:
printf("\n\t Label: %u", EXTRACT_32BITS(tptr) & 0xfffff);
break;
case LDP_TLV_STATUS:
ui = EXTRACT_32BITS(tptr);
tptr+=4;
printf("\n\t Status: 0x%02x, Flags: [%s and %s forward]",
ui&0x3fffffff,
ui&0x80000000 ? "Fatal error" : "Advisory Notification",
ui&0x40000000 ? "do" : "don't");
ui = EXTRACT_32BITS(tptr);
tptr+=4;
if (ui)
printf(", causing Message ID: 0x%08x", ui);
break;
case LDP_TLV_FT_SESSION:
ft_flags = EXTRACT_16BITS(tptr);
printf("\n\t Flags: [%sReconnect, %sSave State, %sAll-Label Protection, %s Checkpoint, %sRe-Learn State]",
ft_flags&0x8000 ? "" : "No ",
ft_flags&0x8 ? "" : "Don't ",
ft_flags&0x4 ? "" : "No ",
ft_flags&0x2 ? "Sequence Numbered Label" : "All Labels",
ft_flags&0x1 ? "" : "Don't ");
tptr+=4;
ui = EXTRACT_32BITS(tptr);
if (ui)
printf(", Reconnect Timeout: %ums", ui);
tptr+=4;
ui = EXTRACT_32BITS(tptr);
if (ui)
printf(", Recovery Time: %ums", ui);
break;
case LDP_TLV_MTU:
printf("\n\t MTU: %u", EXTRACT_16BITS(tptr));
break;
/*
* FIXME those are the defined TLVs that lack a decoder
* you are welcome to contribute code ;-)
*/
case LDP_TLV_HOP_COUNT:
case LDP_TLV_PATH_VECTOR:
case LDP_TLV_ATM_LABEL:
case LDP_TLV_FR_LABEL:
case LDP_TLV_EXTD_STATUS:
case LDP_TLV_RETURNED_PDU:
case LDP_TLV_RETURNED_MSG:
case LDP_TLV_ATM_SESSION_PARM:
case LDP_TLV_FR_SESSION_PARM:
case LDP_TLV_LABEL_REQUEST_MSG_ID:
default:
if (vflag <= 1)
print_unknown_data(tptr,"\n\t ",tlv_tlen);
break;
}
return(tlv_len+4); /* Type & Length fields not included */
trunc:
printf("\n\t\t packet exceeded snapshot");
return 0;
}
void
ldp_print(register const u_char *pptr, register u_int len) {
int processed;
while (len > (sizeof(struct ldp_common_header) + sizeof(struct ldp_msg_header))) {
processed = ldp_msg_print(pptr);
if (processed == 0)
return;
len -= processed;
pptr += processed;
}
}
int
ldp_msg_print(register const u_char *pptr) {
const struct ldp_common_header *ldp_com_header;
const struct ldp_msg_header *ldp_msg_header;
const u_char *tptr,*msg_tptr;
u_short tlen;
u_short pdu_len,msg_len,msg_type,msg_tlen;
int hexdump,processed;
tptr=pptr;
ldp_com_header = (const struct ldp_common_header *)pptr;
TCHECK(*ldp_com_header);
/*
* Sanity checking of the header.
*/
if (EXTRACT_16BITS(&ldp_com_header->version) != LDP_VERSION) {
printf("%sLDP version %u packet not supported",
(vflag < 1) ? "" : "\n\t",
EXTRACT_16BITS(&ldp_com_header->version));
return 0;
}
/* print the LSR-ID, label-space & length */
pdu_len = EXTRACT_16BITS(&ldp_com_header->pdu_length);
printf("%sLDP, Label-Space-ID: %s:%u, pdu-length: %u",
(vflag < 1) ? "" : "\n\t",
ipaddr_string(&ldp_com_header->lsr_id),
EXTRACT_16BITS(&ldp_com_header->label_space),
pdu_len);
/* bail out if non-verbose */
if (vflag < 1)
return 0;
/* ok they seem to want to know everything - lets fully decode it */
tlen=pdu_len;
tptr += sizeof(const struct ldp_common_header);
tlen -= sizeof(const struct ldp_common_header)-4; /* Type & Length fields not included */
while(tlen>0) {
/* did we capture enough for fully decoding the msg header ? */
if (!TTEST2(*tptr, sizeof(struct ldp_msg_header)))
goto trunc;
ldp_msg_header = (const struct ldp_msg_header *)tptr;
msg_len=EXTRACT_16BITS(ldp_msg_header->length);
msg_type=LDP_MASK_MSG_TYPE(EXTRACT_16BITS(ldp_msg_header->type));
/* FIXME vendor private / experimental check */
printf("\n\t %s Message (0x%04x), length: %u, Message ID: 0x%08x, Flags: [%s if unknown]",
tok2str(ldp_msg_values,
"Unknown",
msg_type),
msg_type,
msg_len,
EXTRACT_32BITS(&ldp_msg_header->id),
LDP_MASK_U_BIT(EXTRACT_16BITS(&ldp_msg_header->type)) ? "continue processing" : "ignore");
if (msg_len == 0) /* infinite loop protection */
return 0;
msg_tptr=tptr+sizeof(struct ldp_msg_header);
msg_tlen=msg_len-sizeof(struct ldp_msg_header)+4; /* Type & Length fields not included */
/* did we capture enough for fully decoding the message ? */
if (!TTEST2(*tptr, msg_len))
goto trunc;
hexdump=FALSE;
switch(msg_type) {
case LDP_MSG_NOTIF:
case LDP_MSG_HELLO:
case LDP_MSG_INIT:
case LDP_MSG_KEEPALIVE:
case LDP_MSG_ADDRESS:
case LDP_MSG_LABEL_MAPPING:
case LDP_MSG_ADDRESS_WITHDRAW:
case LDP_MSG_LABEL_WITHDRAW:
while(msg_tlen >= 4) {
processed = ldp_tlv_print(msg_tptr);
if (processed == 0)
break;
msg_tlen-=processed;
msg_tptr+=processed;
}
break;
/*
* FIXME those are the defined messages that lack a decoder
* you are welcome to contribute code ;-)
*/
case LDP_MSG_LABEL_REQUEST:
case LDP_MSG_LABEL_RELEASE:
case LDP_MSG_LABEL_ABORT_REQUEST:
default:
if (vflag <= 1)
print_unknown_data(msg_tptr,"\n\t ",msg_tlen);
break;
}
/* do we want to see an additionally hexdump ? */
if (vflag > 1 || hexdump==TRUE)
print_unknown_data(tptr+sizeof(sizeof(struct ldp_msg_header)),"\n\t ",
msg_len);
tptr += msg_len+4;
tlen -= msg_len+4;
}
return pdu_len+4;
trunc:
printf("\n\t\t packet exceeded snapshot");
return 0;
}