X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/626ad15d6f1ab22a5fd04baf7c67a84f63ddbdde..d2777156522f139a858bd6b5b51e364826bc95a7:/print-icmp.c diff --git a/print-icmp.c b/print-icmp.c index 77539225..54d215e1 100644 --- a/print-icmp.c +++ b/print-icmp.c @@ -86,9 +86,6 @@ struct icmp { #define icmp_data icmp_dun.id_data }; -#define ICMP_MPLS_EXT_EXTRACT_VERSION(x) (((x)&0xf0)>>4) -#define ICMP_MPLS_EXT_VERSION 2 - /* * Lower bounds on packet lengths for various types. * For the error advice packets must first insure that the @@ -150,7 +147,7 @@ struct icmp { ((type) == ICMP_UNREACH || (type) == ICMP_SOURCEQUENCH || \ (type) == ICMP_REDIRECT || (type) == ICMP_TIMXCEED || \ (type) == ICMP_PARAMPROB) -#define ICMP_MPLS_EXT_TYPE(type) \ +#define ICMP_MULTIPART_EXT_TYPE(type) \ ((type) == ICMP_UNREACH || \ (type) == ICMP_TIMXCEED || \ (type) == ICMP_PARAMPROB) @@ -221,13 +218,17 @@ struct id_rdiscovery { }; /* - * draft-bonica-internet-icmp-08 + * RFC 4884 - Extended ICMP to Support Multi-Part Messages + * + * This is a general extension mechanism, based on the mechanism + * in draft-bonica-icmp-mpls-02 ICMP Extensions for MultiProtocol + * Label Switching. * * The Destination Unreachable, Time Exceeded * and Parameter Problem messages are slightly changed as per - * the above draft. A new Length field gets added to give + * the above RFC. A new Length field gets added to give * the caller an idea about the length of the piggybacked - * IP packet before the MPLS extension header starts. + * IP packet before the extension header starts. * * The Length field represents length of the padded "original datagram" * field measured in 32-bit words. @@ -259,15 +260,34 @@ struct icmp_ext_t { nd_byte icmp_ext_data[1]; }; -struct icmp_mpls_ext_object_header_t { +/* + * Extract version from the first octet of icmp_ext_version_res. + */ +#define ICMP_EXT_EXTRACT_VERSION(x) (((x)&0xf0)>>4) + +/* + * Current version. + */ +#define ICMP_EXT_VERSION 2 + +/* + * Extension object class numbers. + * + * Class 1 dates back to draft-bonica-icmp-mpls-02. + */ + +/* rfc4950 */ +#define MPLS_STACK_ENTRY_OBJECT_CLASS 1 + +struct icmp_multipart_ext_object_header_t { nd_uint16_t length; nd_uint8_t class_num; nd_uint8_t ctype; }; -static const struct tok icmp_mpls_ext_obj_values[] = { +static const struct tok icmp_multipart_ext_obj_values[] = { { 1, "MPLS Stack Entry" }, - { 2, "Extended Payload" }, + { 2, "Interface Identification" }, { 0, NULL} }; @@ -305,7 +325,7 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char * const struct udphdr *ouh; const uint8_t *obj_tptr; uint32_t raw_label; - const struct icmp_mpls_ext_object_header_t *icmp_mpls_ext_object_header; + const struct icmp_multipart_ext_object_header_t *icmp_multipart_ext_object_header; u_int hlen, mtu, obj_tlen, obj_class_num, obj_ctype; uint16_t dport; char buf[MAXHOSTNAMELEN + 100]; @@ -675,14 +695,14 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char * ndo->ndo_protocol = "icmp"; /* - * Attempt to decode the MPLS extensions only for some ICMP types. + * Attempt to decode multi-part message extensions (rfc4884) only for some ICMP types. */ - if (ndo->ndo_vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MPLS_EXT_TYPE(icmp_type)) { + if (ndo->ndo_vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MULTIPART_EXT_TYPE(icmp_type)) { ND_TCHECK_SIZE(ext_dp); /* - * Check first if the mpls extension header shows a non-zero length. + * Check first if the multi-part extension header shows a non-zero length. * If the length field is not set then silently verify the checksum * to check if an extension header is present. This is expedient, * however not all implementations set the length field proper. @@ -696,14 +716,14 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char * } } - ND_PRINT("\n\tMPLS extension v%u", - ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res))); + ND_PRINT("\n\tICMP Multi-Part extension v%u", + ICMP_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res))); /* * Sanity checking of the header. */ - if (ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) != - ICMP_MPLS_EXT_VERSION) { + if (ICMP_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) != + ICMP_EXT_VERSION) { ND_PRINT(" packet not supported"); return; } @@ -721,36 +741,36 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char * hlen -= 4; /* subtract common header size */ obj_tptr = (const uint8_t *)ext_dp->icmp_ext_data; - while (hlen > sizeof(struct icmp_mpls_ext_object_header_t)) { + while (hlen > sizeof(struct icmp_multipart_ext_object_header_t)) { - icmp_mpls_ext_object_header = (const struct icmp_mpls_ext_object_header_t *)obj_tptr; - ND_TCHECK_SIZE(icmp_mpls_ext_object_header); - obj_tlen = GET_BE_U_2(icmp_mpls_ext_object_header->length); - obj_class_num = GET_U_1(icmp_mpls_ext_object_header->class_num); - obj_ctype = GET_U_1(icmp_mpls_ext_object_header->ctype); - obj_tptr += sizeof(struct icmp_mpls_ext_object_header_t); + icmp_multipart_ext_object_header = (const struct icmp_multipart_ext_object_header_t *)obj_tptr; + ND_TCHECK_SIZE(icmp_multipart_ext_object_header); + obj_tlen = GET_BE_U_2(icmp_multipart_ext_object_header->length); + obj_class_num = GET_U_1(icmp_multipart_ext_object_header->class_num); + obj_ctype = GET_U_1(icmp_multipart_ext_object_header->ctype); + obj_tptr += sizeof(struct icmp_multipart_ext_object_header_t); ND_PRINT("\n\t %s Object (%u), Class-Type: %u, length %u", - tok2str(icmp_mpls_ext_obj_values,"unknown",obj_class_num), + tok2str(icmp_multipart_ext_obj_values,"unknown",obj_class_num), obj_class_num, obj_ctype, obj_tlen); - hlen-=sizeof(struct icmp_mpls_ext_object_header_t); /* length field includes tlv header */ + hlen-=sizeof(struct icmp_multipart_ext_object_header_t); /* length field includes tlv header */ /* infinite loop protection */ if ((obj_class_num == 0) || - (obj_tlen < sizeof(struct icmp_mpls_ext_object_header_t))) { + (obj_tlen < sizeof(struct icmp_multipart_ext_object_header_t))) { return; } - obj_tlen-=sizeof(struct icmp_mpls_ext_object_header_t); + obj_tlen-=sizeof(struct icmp_multipart_ext_object_header_t); switch (obj_class_num) { - case 1: + case MPLS_STACK_ENTRY_OBJECT_CLASS: switch(obj_ctype) { case 1: raw_label = GET_BE_U_4(obj_tptr); - ND_PRINT("\n\t label %u, exp %u", MPLS_LABEL(raw_label), MPLS_EXP(raw_label)); + ND_PRINT("\n\t label %u, tc %u", MPLS_LABEL(raw_label), MPLS_TC(raw_label)); if (MPLS_STACK(raw_label)) ND_PRINT(", [S]"); ND_PRINT(", ttl %u", MPLS_TTL(raw_label)); @@ -760,11 +780,6 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char * } break; - /* - * FIXME those are the defined objects that lack a decoder - * you are welcome to contribute code ;-) - */ - case 2: default: print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen); break;