X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/544c52e1ef8ee0ba92c7d259c062bbd24a1084eb..ae05d24b8704024d2331d03475a9e6a213b19c69:/print-mpls.c

diff --git a/print-mpls.c b/print-mpls.c
index 69afa17f..a6de5cf1 100644
--- a/print-mpls.c
+++ b/print-mpls.c
@@ -27,40 +27,24 @@
  */
 
 #ifndef lint
-static const char rcsid[] =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-mpls.c,v 1.1 2001-06-21 17:56:04 itojun Exp $ (LBL)";
+static const char rcsid[] _U_ =
+    "@(#) $Header: /tcpdump/master/tcpdump/print-mpls.c,v 1.12 2004-06-14 14:47:58 hannes Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
-#include <sys/param.h>
-#include <sys/time.h>
-#include <sys/socket.h>
+#include <tcpdump-stdinc.h>
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <unistd.h>
 
 #include "addrtoname.h"
 #include "interface.h"
 #include "extract.h"			/* must come after interface.h */
-
-#define LABEL_MASK	0xfffff000
-#define LABEL_SHIFT	12
-#define	EXP_MASK	0x00000e00
-#define EXP_SHIFT	9
-#define	STACK_MASK	0x00000100
-#define STACK_SHIFT	8
-#define TTL_MASK	0x000000ff
-#define TTL_SHIFT	0
-
-#define MPLS_LABEL(x)	(((x) & LABEL_MASK) >> LABEL_SHIFT)
-#define MPLS_EXP(x)	(((x) & EXP_MASK) >> EXP_SHIFT)
-#define MPLS_STACK(x)	(((x) & STACK_MASK) >> STACK_SHIFT)
-#define MPLS_TTL(x)	(((x) & TTL_MASK) >> TTL_SHIFT)
+#include "mpls.h"
 
 static const char *mpls_labelname[] = {
 /*0*/	"IPv4 explicit NULL", "router alert", "IPv6 explicit NULL",
@@ -81,26 +65,27 @@ mpls_print(const u_char *bp, u_int length)
 
 	p = bp;
 	printf("MPLS");
-	TCHECK2(*p, sizeof(v));
-	memcpy(&v, p, sizeof(v));
-	v = (u_int32_t)ntohl(v);
-	printf(" (");	/*)*/
-	printf("label 0x%x", MPLS_LABEL(v));
-	if (vflag &&
-	    MPLS_LABEL(v) < sizeof(mpls_labelname) / sizeof(mpls_labelname[0]))
-		printf("(%s)", mpls_labelname[MPLS_LABEL(v)]);
-	if (MPLS_EXP(v))
-		printf(" exp 0x%x", MPLS_EXP(v));
-	if (MPLS_STACK(v))
-		printf("[S]");
-	printf(" TTL %u", MPLS_TTL(v));
-	/*(*/
-	printf(")");
+	do {
+		TCHECK2(*p, sizeof(v));
+		v = EXTRACT_32BITS(p);
+		printf(" (");	/*)*/
+		printf("label %u", MPLS_LABEL(v));
+		if (vflag &&
+		    MPLS_LABEL(v) < sizeof(mpls_labelname) / sizeof(mpls_labelname[0]))
+			printf(" (%s)", mpls_labelname[MPLS_LABEL(v)]);
+		printf(", exp %u", MPLS_EXP(v));
+		if (MPLS_STACK(v))
+			printf(", [S]");
+		printf(", ttl %u", MPLS_TTL(v));
+		/*(*/
+		printf(")");
 
-	p += sizeof(v);
+		p += sizeof(v);
+	} while (!MPLS_STACK(v));
 
 	switch (MPLS_LABEL(v)) {
 	case 0:	/* IPv4 explicit NULL label */
+        case 3:	/* IPv4 implicit NULL label */
 		ip_print(p, length - (p - bp));
 		break;
 #ifdef INET6
@@ -110,10 +95,76 @@ mpls_print(const u_char *bp, u_int length)
 #endif
 	default:
 		/*
-		 * Since there's no indication of protocol in MPLS label
-		 * encoding, we can print nothing further.
+		 * 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
 		 */
-		return;
+
+                if (MPLS_STACK(v)) { /* 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(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: