X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/7a5c4fb6100582e01df8c7fc99f9381de14071c3..10c9f6fdaa79a650df98ffe98017f282a0fcde4a:/print-icmp.c diff --git a/print-icmp.c b/print-icmp.c index c77c3a4f..46af4f35 100644 --- a/print-icmp.c +++ b/print-icmp.c @@ -30,6 +30,7 @@ #include #include +#define ND_LONGJMP_FROM_TCHECK #include "netdissect.h" #include "addrtoname.h" #include "extract.h" @@ -86,9 +87,6 @@ struct icmp { #define icmp_data icmp_dun.id_data }; -#define ICMP_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 @@ -188,11 +186,6 @@ struct icmp { #define ICMP_UNREACH_PRECEDENCE_CUTOFF 15 /* precedence cutoff */ #endif -/* rfc4950 */ -#define MPLS_STACK_ENTRY_OBJECT_CLASS 1 -/* rfc5837 */ -#define INTERFACE_INFORMATION_OBJECT_CLASS 2 - /* Most of the icmp types */ static const struct tok icmp2str[] = { { ICMP_ECHOREPLY, "echo reply" }, @@ -226,13 +219,17 @@ 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. @@ -264,6 +261,32 @@ struct icmp_ext_t { nd_byte icmp_ext_data[1]; }; +/* + * 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. + * + * Class 2 was used for an "Extended Payload Object Class", which + * contained bytes of the payload beyond the first 128 bytes, in + * draft-bonica-icmp-mpls-02; it was reassigned to an "Interface + * Information Object" in RFC 5837. + */ + +/* rfc4950 */ +#define MPLS_STACK_ENTRY_OBJECT_CLASS 1 +/* rfc5837 */ +#define INTERFACE_INFORMATION_OBJECT_CLASS 2 + struct icmp_multipart_ext_object_header_t { nd_uint16_t length; nd_uint8_t class_num; @@ -271,17 +294,17 @@ struct icmp_multipart_ext_object_header_t { }; static const struct tok icmp_multipart_ext_obj_values[] = { - { 1, "MPLS Stack Entry" }, - { 2, "Interface Identification" }, + { 1, "MPLS Stack Entry Object" }, + { 2, "Interface Information Object" }, { 0, NULL} }; /* rfc5837 */ -static const struct tok icmp_interface_identification_role_values[] = { - { 0, "the IP interface upon which a datagram arrived"}, - { 1, "the sub-IP component of an IP interface upon which a datagram arrived"}, - { 2, "the IP interface through which the datagram would have been forwarded had it been forwardable"}, - { 3, "the IP next hop to which the datagram would have been forwarded"}, +static const struct tok icmp_interface_information_role_values[] = { + { 0, "Incoming IP Interface"}, + { 1, "Sub-IP Component of Incoming IP Interface"}, + { 2, "Outgoing IP Interface"}, + { 3, "IP Next hop"}, { 0, NULL } }; @@ -293,7 +316,7 @@ Interface IP Address Sub-Object +-------+-------+-------+-------+ | IP Address .... */ -struct icmp_interface_identification_ipaddr_subobject_t { +struct icmp_interface_information_ipaddr_subobject_t { nd_uint16_t afi; nd_uint16_t reserved; nd_uint32_t ip_addr; @@ -306,12 +329,11 @@ octet 0 1 63 | length | interface name octets 1-63 | +--------+-----------................-----------------+ */ -struct icmp_interface_identification_ifname_subobject_t { +struct icmp_interface_information_ifname_subobject_t { nd_uint8_t length; nd_byte if_name[63]; }; - /* prototypes */ const char *icmp_tstamp_print(u_int); @@ -331,35 +353,158 @@ icmp_tstamp_print(u_int tstamp) return buf; } +static int +print_icmp_multipart_ext_object(netdissect_options *ndo, const uint8_t *obj_tptr) +{ + u_int obj_tlen, obj_class_num, obj_ctype; + const struct icmp_multipart_ext_object_header_t *icmp_multipart_ext_object_header; + + icmp_multipart_ext_object_header = (const struct icmp_multipart_ext_object_header_t *)obj_tptr; + 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 (%u), Class-Type: %u, length %u", + tok2str(icmp_multipart_ext_obj_values,"unknown",obj_class_num), + obj_class_num, + obj_ctype, + obj_tlen); + + /* infinite loop protection */ + if ((obj_class_num == 0) || + (obj_tlen < sizeof(struct icmp_multipart_ext_object_header_t))) { + return -1; + } + obj_tlen -= sizeof(struct icmp_multipart_ext_object_header_t); + + switch (obj_class_num) { + case MPLS_STACK_ENTRY_OBJECT_CLASS: + switch(obj_ctype) { + case 1: + { + uint32_t raw_label; + + raw_label = GET_BE_U_4(obj_tptr); + 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)); + break; + } + default: + print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen); + } + break; + + case INTERFACE_INFORMATION_OBJECT_CLASS: + { + /* + Ctype in a INTERFACE_INFORMATION_OBJECT_CLASS object: + + Bit 0 1 2 3 4 5 6 7 + +-------+-------+-------+-------+-------+-------+-------+-------+ + | Interface Role| Rsvd1 | Rsvd2 |ifIndex| IPAddr| name | MTU | + +-------+-------+-------+-------+-------+-------+-------+-------+ + */ + const uint8_t *offset; + u_int interface_role, if_index_flag, ipaddr_flag, name_flag, mtu_flag; + + interface_role = (obj_ctype & 0xc0) >> 6; + if_index_flag = (obj_ctype & 0x8) >> 3; + ipaddr_flag = (obj_ctype & 0x4) >> 2; + name_flag = (obj_ctype & 0x2) >> 1; + mtu_flag = (obj_ctype & 0x1); + + ND_PRINT("\n\t Interface Role: %s", + tok2str(icmp_interface_information_role_values, + "an unknown interface role",interface_role)); + + offset = obj_tptr; + + if (if_index_flag) { + ND_PRINT("\n\t Interface Index: %u", GET_BE_U_4(offset)); + offset += 4; + } + if (ipaddr_flag) { + const struct icmp_interface_information_ipaddr_subobject_t *ipaddr_subobj; + + ND_PRINT("\n\t IP Address sub-object: "); + ipaddr_subobj = (const struct icmp_interface_information_ipaddr_subobject_t *) offset; + switch (GET_BE_U_2(ipaddr_subobj->afi)) { + case 1: + ND_PRINT("%s", GET_IPADDR_STRING(ipaddr_subobj->ip_addr)); + offset += 4; + break; + case 2: + ND_PRINT("%s", GET_IP6ADDR_STRING(ipaddr_subobj->ip_addr)); + offset += 16; + break; + default: + ND_PRINT("Unknown Address Family Identifier"); + return -1; + } + offset += 4; + } + if (name_flag) { + uint8_t inft_name_length_field; + const struct icmp_interface_information_ifname_subobject_t *ifname_subobj; + + ifname_subobj = (const struct icmp_interface_information_ifname_subobject_t *) offset; + inft_name_length_field = GET_U_1(ifname_subobj->length); + ND_PRINT("\n\t Interface Name"); + if (inft_name_length_field == 0) { + ND_PRINT(" [length %u]", inft_name_length_field); + nd_print_invalid(ndo); + break; + } + if (inft_name_length_field % 4 != 0) { + ND_PRINT(" [length %u != N x 4]", inft_name_length_field); + nd_print_invalid(ndo); + offset += inft_name_length_field; + break; + } + if (inft_name_length_field > 64) { + ND_PRINT(" [length %u > 64]", inft_name_length_field); + nd_print_invalid(ndo); + offset += inft_name_length_field; + break; + } + ND_PRINT(", length %u: ", inft_name_length_field); + nd_printjnp(ndo, ifname_subobj->if_name, + inft_name_length_field - 1); + offset += inft_name_length_field; + } + if (mtu_flag) { + ND_PRINT("\n\t MTU: %u", GET_BE_U_4(offset)); + offset += 4; + } + break; + } + + default: + print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen); + break; + } + return obj_tlen + sizeof(struct icmp_multipart_ext_object_header_t); +} + void -icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *bp2, +icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, int fragmented) { - char *cp; const struct icmp *dp; uint8_t icmp_type, icmp_code; - const struct icmp_ext_t *ext_dp; - const struct ip *ip; + const struct icmp_ext_t *ext_dp; const char *str; - const struct ip *oip; - uint8_t ip_proto; - const struct udphdr *ouh; - const uint8_t *obj_tptr; - uint32_t raw_label; - const struct icmp_multipart_ext_object_header_t *icmp_multipart_ext_object_header; - u_int interface_role, if_index_flag, ipaddr_flag, name_flag, mtu_flag; - const uint8_t *offset; - const struct icmp_interface_identification_ipaddr_subobject_t *ipaddr_subobj; - const struct icmp_interface_identification_ifname_subobject_t *ifname_subobj; - u_int hlen, mtu, obj_tlen, obj_class_num, obj_ctype; - uint16_t dport; + const uint8_t *obj_tptr; + u_int hlen; char buf[MAXHOSTNAMELEN + 100]; struct cksum_vec vec[1]; ndo->ndo_protocol = "icmp"; dp = (const struct icmp *)bp; - ext_dp = (const struct icmp_ext_t *)bp; - ip = (const struct ip *)bp2; + ext_dp = (const struct icmp_ext_t *)bp; str = buf; icmp_type = GET_U_1(dp->icmp_type); @@ -398,7 +543,12 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char * break; case ICMP_UNREACH_PORT: - ND_TCHECK_1(dp->icmp_ip.ip_p); + { + const struct ip *oip; + const struct udphdr *ouh; + uint8_t ip_proto; + uint16_t dport; + oip = &dp->icmp_ip; hlen = IP_HL(oip) * 4; ouh = (const struct udphdr *)(((const u_char *)oip) + hlen); @@ -428,10 +578,13 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char * break; } break; + } case ICMP_UNREACH_NEEDFRAG: { const struct mtu_discovery *mp; + u_int mtu; + mp = (const struct mtu_discovery *)(const u_char *)&dp->icmp_void; mtu = GET_BE_U_2(mp->nexthopmtu); if (mtu) { @@ -563,6 +716,7 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char * case ICMP_ROUTERADVERT: { + char *cp; const struct ih_rdiscovery *ihp; const struct id_rdiscovery *idp; u_int lifetime, num, size; @@ -571,7 +725,6 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char * cp = buf + strlen(buf); ihp = (const struct ih_rdiscovery *)&dp->icmp_void; - ND_TCHECK_SIZE(ihp); (void)strncpy(cp, " lifetime ", sizeof(buf) - (cp - buf)); cp = buf + strlen(buf); lifetime = GET_BE_U_2(ihp->ird_lifetime); @@ -602,13 +755,12 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char * } idp = (const struct id_rdiscovery *)&dp->icmp_data; while (num > 0) { - ND_TCHECK_SIZE(idp); (void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}", GET_IPADDR_STRING(idp->ird_addr), GET_BE_U_4(idp->ird_pref)); cp = buf + strlen(buf); ++idp; - num--; + num--; } } break; @@ -656,7 +808,6 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char * break; case ICMP_TSTAMPREPLY: - ND_TCHECK_4(dp->icmp_ttime); (void)snprintf(buf, sizeof(buf), "time stamp reply id %u seq %u: org %s", GET_BE_U_2(dp->icmp_id), @@ -695,6 +846,7 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char * * save the snaplength as this may get overridden in the IP printer. */ if (ndo->ndo_vflag >= 1 && ICMP_ERRTYPE(icmp_type)) { + const struct ip *ip; const u_char *snapend_save; bp += 8; @@ -723,7 +875,6 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char * * Attempt to decode multi-part message extensions (rfc4884) only for some ICMP types. */ if (ndo->ndo_vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MULTIPART_EXT_TYPE(icmp_type)) { - ND_TCHECK_SIZE(ext_dp); /* @@ -748,7 +899,7 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char * * Sanity checking of the header. */ if (ICMP_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) != - ICMP_MPLS_EXT_VERSION) { + ICMP_EXT_VERSION) { ND_PRINT(" packet not supported"); return; } @@ -767,112 +918,15 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char * obj_tptr = (const uint8_t *)ext_dp->icmp_ext_data; while (hlen > sizeof(struct icmp_multipart_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_multipart_ext_obj_values,"unknown",obj_class_num), - obj_class_num, - obj_ctype, - obj_tlen); - - 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_multipart_ext_object_header_t))) { + int obj_tlen = print_icmp_multipart_ext_object(ndo, obj_tptr); + if (obj_tlen < 0) { + /* malformed object */ return; } - obj_tlen-=sizeof(struct icmp_multipart_ext_object_header_t); - - switch (obj_class_num) { - 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, 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)); - break; - default: - print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen); - } - break; - - case INTERFACE_INFORMATION_OBJECT_CLASS: - /* - Ctype in a INTERFACE_INFORMATION_OBJECT_CLASS object: - - Bit 0 1 2 3 4 5 6 7 - +-------+-------+-------+-------+-------+-------+-------+-------+ - | Interface Role| Rsvd1 | Rsvd2 |ifIndex| IPAddr| name | MTU | - +-------+-------+-------+-------+-------+-------+-------+-------+ - */ - interface_role = (obj_ctype & 0xc0) >> 6; - if_index_flag = (obj_ctype & 0x8) >> 3; - ipaddr_flag = (obj_ctype & 0x4) >> 2; - name_flag = (obj_ctype & 0x2) >> 1; - mtu_flag = (obj_ctype & 0x1); - - ND_PRINT("\n\t\t This object describes %s", - tok2str(icmp_interface_identification_role_values, - "an unknown interface role",interface_role)); - - offset = obj_tptr; - - if (if_index_flag) { - ND_PRINT("\n\t\t Interface Index: %u", GET_BE_U_4(offset)); - offset += 4; - } - if (ipaddr_flag) { - ND_PRINT("\n\t\t IP Address sub-object: "); - ipaddr_subobj = (const struct icmp_interface_identification_ipaddr_subobject_t *) offset; - switch (GET_BE_U_2(ipaddr_subobj->afi)) { - case 1: - ND_PRINT("%s", GET_IPADDR_STRING(ipaddr_subobj->ip_addr)); - offset += 4; - break; - case 2: - ND_PRINT("%s", GET_IP6ADDR_STRING(ipaddr_subobj->ip_addr)); - offset += 16; - break; - default: - ND_PRINT("Unknown Address Family Identifier"); - return; - } - offset += 4; - } - if (name_flag) { - ifname_subobj = (const struct icmp_interface_identification_ifname_subobject_t *) offset; - ND_PRINT("\n\t\t Interface Name: %.*s", - GET_U_1(ifname_subobj->length), - ifname_subobj->if_name); - offset += 1 + GET_U_1(ifname_subobj->length); - } - if (mtu_flag) { - ND_PRINT("\n\t\t MTU: %u", GET_BE_U_4(offset)); - offset += 4; - } - break; - - default: - print_unknown_data(ndo, obj_tptr, "\n\t ", obj_tlen); - break; - } - if (hlen < obj_tlen) + if (hlen < (u_int)obj_tlen) break; hlen -= obj_tlen; obj_tptr += obj_tlen; } } - - return; -trunc: - nd_print_trunc(ndo); }