| /* |
| * 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. |
| */ |
| |
| /* \summary: Multi-Protocol Label Switching (MPLS) printer */ |
| |
| #ifdef HAVE_CONFIG_H |
| #include <config.h> |
| #endif |
| |
| #include "netdissect-stdinc.h" |
| |
| #define ND_LONGJMP_FROM_TCHECK |
| #include "netdissect.h" |
| #include "extract.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", |
| }; |
| |
| enum mpls_packet_type { |
| PT_UNKNOWN, |
| PT_IPV4, |
| PT_IPV6, |
| PT_OSI |
| }; |
| |
| /* |
| * RFC3032: MPLS label stack encoding |
| */ |
| void |
| mpls_print(netdissect_options *ndo, const u_char *bp, u_int length) |
| { |
| const u_char *p; |
| uint32_t label_entry; |
| uint16_t label_stack_depth = 0; |
| uint8_t first; |
| enum mpls_packet_type pt = PT_UNKNOWN; |
| |
| ndo->ndo_protocol = "mpls"; |
| p = bp; |
| nd_print_protocol_caps(ndo); |
| do { |
| if (length < sizeof(label_entry)) |
| goto invalid; |
| label_entry = GET_BE_U_4(p); |
| ND_PRINT("%s(label %u", |
| (label_stack_depth && ndo->ndo_vflag) ? "\n\t" : " ", |
| MPLS_LABEL(label_entry)); |
| label_stack_depth++; |
| if (ndo->ndo_vflag && |
| MPLS_LABEL(label_entry) < sizeof(mpls_labelname) / sizeof(mpls_labelname[0])) |
| ND_PRINT(" (%s)", mpls_labelname[MPLS_LABEL(label_entry)]); |
| ND_PRINT(", tc %u", MPLS_TC(label_entry)); |
| if (MPLS_STACK(label_entry)) |
| ND_PRINT(", [S]"); |
| ND_PRINT(", ttl %u)", MPLS_TTL(label_entry)); |
| |
| p += sizeof(label_entry); |
| length -= sizeof(label_entry); |
| } while (!MPLS_STACK(label_entry)); |
| |
| /* |
| * Try to figure out the packet type. |
| */ |
| switch (MPLS_LABEL(label_entry)) { |
| |
| case 0: /* IPv4 explicit NULL label */ |
| case 3: /* IPv4 implicit NULL label */ |
| pt = PT_IPV4; |
| break; |
| |
| case 2: /* IPv6 explicit NULL label */ |
| pt = PT_IPV6; |
| break; |
| |
| default: |
| /* |
| * Generally there's no indication of protocol in MPLS label |
| * encoding. |
| * |
| * However, draft-hsmit-isis-aal5mux-00.txt describes a |
| * technique for encapsulating IS-IS and IP traffic on the |
| * same ATM virtual circuit; you look at the first payload |
| * byte to determine the network layer protocol, based on |
| * the fact that |
| * |
| * 1) the first byte of an IP header is 0x45-0x4f |
| * for IPv4 and 0x60-0x6f for IPv6; |
| * |
| * 2) the first byte of an OSI CLNP packet is 0x81, |
| * the first byte of an OSI ES-IS packet is 0x82, |
| * and the first byte of an OSI IS-IS packet is |
| * 0x83; |
| * |
| * so the network layer protocol can be inferred from the |
| * first byte of the packet, if the protocol is one of the |
| * ones listed above. |
| * |
| * Cisco sends control-plane traffic MPLS-encapsulated in |
| * this fashion. |
| */ |
| if (length < 1) { |
| /* nothing to print */ |
| return; |
| } |
| first = GET_U_1(p); |
| pt = |
| (first >= 0x45 && first <= 0x4f) ? PT_IPV4 : |
| (first >= 0x60 && first <= 0x6f) ? PT_IPV6 : |
| (first >= 0x81 && first <= 0x83) ? PT_OSI : |
| /* ok bail out - we did not figure out what it is*/ |
| PT_UNKNOWN; |
| } |
| |
| /* |
| * Print the payload. |
| */ |
| switch (pt) { |
| case PT_UNKNOWN: |
| if (!ndo->ndo_suppress_default_print) |
| ND_DEFAULTPRINT(p, length); |
| break; |
| |
| case PT_IPV4: |
| ND_PRINT(ndo->ndo_vflag ? "\n\t" : " "); |
| ip_print(ndo, p, length); |
| break; |
| |
| case PT_IPV6: |
| ND_PRINT(ndo->ndo_vflag ? "\n\t" : " "); |
| ip6_print(ndo, p, length); |
| break; |
| |
| case PT_OSI: |
| ND_PRINT(ndo->ndo_vflag ? "\n\t" : " "); |
| isoclns_print(ndo, p, length); |
| break; |
| } |
| return; |
| |
| invalid: |
| nd_print_invalid(ndo); |
| ND_TCHECK_LEN(p, length); |
| } |