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/* $OpenBSD: print-mpls.c,v 1.3 2016/07/11 00:27:50 rzalamena Exp $ */
/*
* Copyright (c) 2005 Jason L. Wright (jason@thought.net)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/socket.h>
#include <sys/types.h>
#include <netmpls/mpls.h>
#include <stdio.h>
#include "interface.h"
#include "extract.h" /* must come after interface.h */
#define CW_SEQUENCE_MASK (0x0000ffffU)
int controlword_tryprint(const u_char **, u_int *);
void
mpls_print(const u_char *bp, u_int len)
{
u_int32_t tag, label, exp, bottom, ttl;
int has_cw;
again:
if (bp + sizeof(tag) > snapend)
goto trunc;
tag = EXTRACT_32BITS(bp);
bp += sizeof(tag);
len -= sizeof(tag);
label = (tag >> 12) & 0xfffff;
exp = (tag >> 9) & 0x7;
bottom = (tag >> 8) & 0x1;
ttl = (tag >> 0) & 0xff;
printf("MPLS(label %u, exp %u, ttl %u) ", label, exp, ttl);
/* XXX decode "Router Alert Label" */
if (!bottom)
goto again;
/* Handle pseudowire control word. */
has_cw = controlword_tryprint(&bp, &len);
/*
* guessing the underlying protocol is about all we can do if
* it's not explicitly defined.
*/
switch (label) {
case 0x00000: /* IPv4 Explicit NULL */
ip_print(bp, len);
break;
case 0x00001: /* Router Alert */
/* shouldn't happen at stack bottom */
printf("Route-Alert");
break;
case 0x00002: /* IPv6 Explicit NULL */
ip6_print(bp, len);
break;
case 0x00003: /* Implicit NULL */
/* shouldn't happen in the tag stack */
printf("Implicit-NULL");
break;
case 0x00004: /* reserved labels */
case 0x00005:
case 0x00006:
case 0x00007:
case 0x00008:
case 0x00009:
case 0x0000a:
case 0x0000b:
case 0x0000c:
case 0x0000d:
case 0x0000e:
case 0x0000f:
break;
default: /* dunno, guess? */
if (len == 0)
break;
if (bp >= snapend)
goto trunc;
switch (bp[0] & 0xf0) {
case 0x40:
ip_print(bp, len);
break;
case 0x60:
ip6_print(bp, len);
break;
}
}
if (has_cw)
ether_tryprint(bp, len, 0);
return;
trunc:
printf("[|mpls]");
}
/* Print control word if any and returns 1 on success. */
int
controlword_tryprint(const u_char **bp, u_int *lenp)
{
uint32_t cw, frag, seq;
if (*lenp < 4)
return (0);
cw = EXTRACT_32BITS(*bp);
if (cw & CW_ZERO_MASK)
return (0);
*bp += sizeof(cw);
*lenp += sizeof(cw);
frag = (cw & CW_FRAG_MASK) >> 16;
seq = cw & CW_SEQUENCE_MASK;
printf("CW(frag %u, sequence %u) ", frag, seq);
return (1);
}
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