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Diffstat (limited to 'contrib/tcpdump/print-mpls.c')
| -rw-r--r-- | contrib/tcpdump/print-mpls.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/contrib/tcpdump/print-mpls.c b/contrib/tcpdump/print-mpls.c new file mode 100644 index 0000000..c6b0814 --- /dev/null +++ b/contrib/tcpdump/print-mpls.c @@ -0,0 +1,189 @@ +/* + * Copyright (C) 2001 WIDE Project. 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. + * 3. Neither the name of the project 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 BY THE PROJECT AND CONTRIBUTORS ``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 PROJECT OR CONTRIBUTORS 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. + */ + +#ifndef lint +static const char rcsid[] _U_ = + "@(#) $Header: /tcpdump/master/tcpdump/print-mpls.c,v 1.14 2005-07-05 09:38:19 hannes Exp $ (LBL)"; +#endif + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <tcpdump-stdinc.h> + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "addrtoname.h" +#include "interface.h" +#include "extract.h" /* must come after interface.h */ +#include "mpls.h" + +static const char *mpls_labelname[] = { +/*0*/ "IPv4 explicit NULL", "router alert", "IPv6 explicit NULL", + "implicit NULL", "rsvd", +/*5*/ "rsvd", "rsvd", "rsvd", "rsvd", "rsvd", +/*10*/ "rsvd", "rsvd", "rsvd", "rsvd", "rsvd", +/*15*/ "rsvd", +}; + +/* + * RFC3032: MPLS label stack encoding + */ +void +mpls_print(const u_char *bp, u_int length) +{ + const u_char *p; + u_int32_t label_entry; + u_int16_t label_stack_depth = 0; + + p = bp; + printf("MPLS"); + do { + TCHECK2(*p, sizeof(label_entry)); + label_entry = EXTRACT_32BITS(p); + printf("%s(label %u", + label_stack_depth ? "\n\t" : " ", + MPLS_LABEL(label_entry)); + label_stack_depth++; + if (vflag && + MPLS_LABEL(label_entry) < sizeof(mpls_labelname) / sizeof(mpls_labelname[0])) + printf(" (%s)", mpls_labelname[MPLS_LABEL(label_entry)]); + printf(", exp %u", MPLS_EXP(label_entry)); + if (MPLS_STACK(label_entry)) + printf(", [S]"); + printf(", ttl %u)", MPLS_TTL(label_entry)); + + p += sizeof(label_entry); + } while (!MPLS_STACK(label_entry)); + + switch (MPLS_LABEL(label_entry)) { + case 0: /* IPv4 explicit NULL label */ + case 3: /* IPv4 implicit NULL label */ + if (vflag>0) { + printf("\n\t"); + ip_print(gndo, p, length - (p - bp)); + } + else printf(", IP, length: %u",length); + break; +#ifdef INET6 + case 2: /* IPv6 explicit NULL label */ + if (vflag>0) { + printf("\n\t"); + ip6_print(p, length - (p - bp)); + } + else printf(", IPv6, length: %u",length); + break; +#endif + default: + /* + * Generally there's no indication of protocol in MPLS label + * encoding, however draft-hsmit-isis-aal5mux-00.txt describes + * a technique that looks at the first payload byte if the BOS (bottom of stack) + * bit is set and tries to determine the network layer protocol + * 0x45-0x4f is IPv4 + * 0x60-0x6f is IPv6 + * 0x81-0x83 is OSI (CLNP,ES-IS,IS-IS) + * this technique is sometimes known as NULL encapsulation + * and decoding is particularly useful for control-plane traffic [BGP] + * which cisco by default sends MPLS encapsulated + */ + + if (MPLS_STACK(label_entry)) { /* only do this if the stack bit is set */ + switch(*p) { + case 0x45: + case 0x46: + case 0x47: + case 0x48: + case 0x49: + case 0x4a: + case 0x4b: + case 0x4c: + case 0x4d: + case 0x4e: + case 0x4f: + if (vflag>0) { + printf("\n\t"); + ip_print(gndo, p, length - (p - bp)); + } + else printf(", IP, length: %u",length); + break; +#ifdef INET6 + case 0x60: + case 0x61: + case 0x62: + case 0x63: + case 0x64: + case 0x65: + case 0x66: + case 0x67: + case 0x68: + case 0x69: + case 0x6a: + case 0x6b: + case 0x6c: + case 0x6d: + case 0x6e: + case 0x6f: + if (vflag>0) { + printf("\n\t"); + ip6_print(p, length - (p - bp)); + } + else printf(", IPv6, length: %u",length); + break; +#endif + case 0x81: + case 0x82: + case 0x83: + if (vflag>0) { + printf("\n\t"); + isoclns_print(p, length - (p - bp), length - (p - bp)); + } + else printf(", OSI, length: %u",length); + break; + default: + /* ok bail out - we did not figure out what it is*/ + break; + } + } + return; + } + +trunc: + printf("[|MPLS]"); +} + + +/* + * Local Variables: + * c-style: whitesmith + * c-basic-offset: 8 + * End: + */ |
