X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/442abdb79c13b07a32d2c54a1a722ab841235a83..b116cd9ac44b940cdda9493bb77e81ea42f1db7d:/print-mpls.c diff --git a/print-mpls.c b/print-mpls.c index c579dd79..c6b0814f 100644 --- a/print-mpls.c +++ b/print-mpls.c @@ -27,42 +27,24 @@ */ #ifndef lint -static const char rcsid[] = - "@(#) $Header: /tcpdump/master/tcpdump/print-mpls.c,v 1.2 2001-06-26 06:24:57 guy Exp $ (LBL)"; +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 -#include -#include - -#include +#include #include #include #include -#include #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", @@ -79,45 +61,129 @@ void mpls_print(const u_char *bp, u_int length) { const u_char *p; - u_int32_t v; + u_int32_t label_entry; + u_int16_t label_stack_depth = 0; 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(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(v); + p += sizeof(label_entry); + } while (!MPLS_STACK(label_entry)); - switch (MPLS_LABEL(v)) { + switch (MPLS_LABEL(label_entry)) { case 0: /* IPv4 explicit NULL label */ - ip_print(p, length - (p - bp)); + 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 */ - ip6_print(p, length - (p - bp)); + if (vflag>0) { + printf("\n\t"); + ip6_print(p, length - (p - bp)); + } + else printf(", IPv6, length: %u",length); break; #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(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: + */