/* \summary: Internet Control Message Protocol (ICMP) printer */
-#ifdef HAVE_CONFIG_H
#include <config.h>
-#endif
#include "netdissect-stdinc.h"
#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
- * packet is large enought to contain the returned ip header.
+ * packet is large enough to contain the returned ip header.
* Only then can we do the check to see if 64 bits of packet
* data have been returned, since we need to check the returned
* ip header length.
((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)
};
/*
- * 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 caller an idea about the length of the piggypacked
- * IP packet before the MPLS extension header starts.
+ * 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 extension header starts.
*
* The Length field represents length of the padded "original datagram"
* field measured in 32-bit words.
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}
};
const struct udphdr *ouh;
const uint8_t *obj_tptr;
uint32_t raw_label;
- const u_char *snapend_save;
- 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];
ip = (const struct ip *)bp2;
str = buf;
- ND_TCHECK_1(dp->icmp_code);
icmp_type = GET_U_1(dp->icmp_type);
icmp_code = GET_U_1(dp->icmp_code);
switch (icmp_type) {
case ICMP_ECHO:
case ICMP_ECHOREPLY:
- ND_TCHECK_2(dp->icmp_seq);
(void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u",
icmp_type == ICMP_ECHO ?
"request" : "reply",
break;
case ICMP_UNREACH:
- ND_TCHECK_4(dp->icmp_ip.ip_dst);
switch (icmp_code) {
case ICMP_UNREACH_NET:
(void)snprintf(buf, sizeof(buf),
"net %s unreachable",
- ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+ GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
break;
case ICMP_UNREACH_HOST:
(void)snprintf(buf, sizeof(buf),
"host %s unreachable",
- ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+ GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
break;
case ICMP_UNREACH_PROTOCOL:
- ND_TCHECK_1(dp->icmp_ip.ip_p);
(void)snprintf(buf, sizeof(buf),
"%s protocol %u unreachable",
- ipaddr_string(ndo, dp->icmp_ip.ip_dst),
+ GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
GET_U_1(dp->icmp_ip.ip_p));
break;
oip = &dp->icmp_ip;
hlen = IP_HL(oip) * 4;
ouh = (const struct udphdr *)(((const u_char *)oip) + hlen);
- ND_TCHECK_2(ouh->uh_dport);
dport = GET_BE_U_2(ouh->uh_dport);
ip_proto = GET_U_1(oip->ip_p);
switch (ip_proto) {
case IPPROTO_TCP:
(void)snprintf(buf, sizeof(buf),
"%s tcp port %s unreachable",
- ipaddr_string(ndo, oip->ip_dst),
+ GET_IPADDR_STRING(oip->ip_dst),
tcpport_string(ndo, dport));
break;
case IPPROTO_UDP:
(void)snprintf(buf, sizeof(buf),
"%s udp port %s unreachable",
- ipaddr_string(ndo, oip->ip_dst),
+ GET_IPADDR_STRING(oip->ip_dst),
udpport_string(ndo, dport));
break;
default:
(void)snprintf(buf, sizeof(buf),
"%s protocol %u port %u unreachable",
- ipaddr_string(ndo, oip->ip_dst),
+ GET_IPADDR_STRING(oip->ip_dst),
ip_proto, dport);
break;
}
if (mtu) {
(void)snprintf(buf, sizeof(buf),
"%s unreachable - need to frag (mtu %u)",
- ipaddr_string(ndo, dp->icmp_ip.ip_dst), mtu);
+ GET_IPADDR_STRING(dp->icmp_ip.ip_dst), mtu);
} else {
(void)snprintf(buf, sizeof(buf),
"%s unreachable - need to frag",
- ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+ GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
}
}
break;
case ICMP_UNREACH_SRCFAIL:
(void)snprintf(buf, sizeof(buf),
"%s unreachable - source route failed",
- ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+ GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
break;
case ICMP_UNREACH_NET_UNKNOWN:
(void)snprintf(buf, sizeof(buf),
"net %s unreachable - unknown",
- ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+ GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
break;
case ICMP_UNREACH_HOST_UNKNOWN:
(void)snprintf(buf, sizeof(buf),
"host %s unreachable - unknown",
- ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+ GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
break;
case ICMP_UNREACH_ISOLATED:
(void)snprintf(buf, sizeof(buf),
"%s unreachable - source host isolated",
- ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+ GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
break;
case ICMP_UNREACH_NET_PROHIB:
(void)snprintf(buf, sizeof(buf),
"net %s unreachable - admin prohibited",
- ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+ GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
break;
case ICMP_UNREACH_HOST_PROHIB:
(void)snprintf(buf, sizeof(buf),
"host %s unreachable - admin prohibited",
- ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+ GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
break;
case ICMP_UNREACH_TOSNET:
(void)snprintf(buf, sizeof(buf),
"net %s unreachable - tos prohibited",
- ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+ GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
break;
case ICMP_UNREACH_TOSHOST:
(void)snprintf(buf, sizeof(buf),
"host %s unreachable - tos prohibited",
- ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+ GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
break;
case ICMP_UNREACH_FILTER_PROHIB:
(void)snprintf(buf, sizeof(buf),
"host %s unreachable - admin prohibited filter",
- ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+ GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
break;
case ICMP_UNREACH_HOST_PRECEDENCE:
(void)snprintf(buf, sizeof(buf),
"host %s unreachable - host precedence violation",
- ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+ GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
break;
case ICMP_UNREACH_PRECEDENCE_CUTOFF:
(void)snprintf(buf, sizeof(buf),
"host %s unreachable - precedence cutoff",
- ipaddr_string(ndo, dp->icmp_ip.ip_dst));
+ GET_IPADDR_STRING(dp->icmp_ip.ip_dst));
break;
default:
(void)snprintf(buf, sizeof(buf),
"%s unreachable - #%u",
- ipaddr_string(ndo, dp->icmp_ip.ip_dst),
+ GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
icmp_code);
break;
}
break;
case ICMP_REDIRECT:
- ND_TCHECK_4(dp->icmp_ip.ip_dst);
switch (icmp_code) {
case ICMP_REDIRECT_NET:
(void)snprintf(buf, sizeof(buf),
"redirect %s to net %s",
- ipaddr_string(ndo, dp->icmp_ip.ip_dst),
- ipaddr_string(ndo, dp->icmp_gwaddr));
+ GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
+ GET_IPADDR_STRING(dp->icmp_gwaddr));
break;
case ICMP_REDIRECT_HOST:
(void)snprintf(buf, sizeof(buf),
"redirect %s to host %s",
- ipaddr_string(ndo, dp->icmp_ip.ip_dst),
- ipaddr_string(ndo, dp->icmp_gwaddr));
+ GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
+ GET_IPADDR_STRING(dp->icmp_gwaddr));
break;
case ICMP_REDIRECT_TOSNET:
(void)snprintf(buf, sizeof(buf),
"redirect-tos %s to net %s",
- ipaddr_string(ndo, dp->icmp_ip.ip_dst),
- ipaddr_string(ndo, dp->icmp_gwaddr));
+ GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
+ GET_IPADDR_STRING(dp->icmp_gwaddr));
break;
case ICMP_REDIRECT_TOSHOST:
(void)snprintf(buf, sizeof(buf),
"redirect-tos %s to host %s",
- ipaddr_string(ndo, dp->icmp_ip.ip_dst),
- ipaddr_string(ndo, dp->icmp_gwaddr));
+ GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
+ GET_IPADDR_STRING(dp->icmp_gwaddr));
break;
default:
(void)snprintf(buf, sizeof(buf),
"redirect-#%u %s to %s", icmp_code,
- ipaddr_string(ndo, dp->icmp_ip.ip_dst),
- ipaddr_string(ndo, dp->icmp_gwaddr));
+ GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
+ GET_IPADDR_STRING(dp->icmp_gwaddr));
break;
}
break;
while (num > 0) {
ND_TCHECK_SIZE(idp);
(void)snprintf(cp, sizeof(buf) - (cp - buf), " {%s %u}",
- ipaddr_string(ndo, idp->ird_addr),
+ GET_IPADDR_STRING(idp->ird_addr),
GET_BE_U_4(idp->ird_pref));
cp = buf + strlen(buf);
++idp;
(void)snprintf(buf, sizeof(buf),
"parameter problem - code %u", icmp_code);
else {
- ND_TCHECK_1(dp->icmp_pptr);
(void)snprintf(buf, sizeof(buf),
"parameter problem - octet %u",
GET_U_1(dp->icmp_pptr));
break;
case ICMP_MASKREPLY:
- ND_TCHECK_4(dp->icmp_mask);
(void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
GET_BE_U_4(dp->icmp_mask));
break;
case ICMP_TSTAMP:
- ND_TCHECK_2(dp->icmp_seq);
(void)snprintf(buf, sizeof(buf),
"time stamp query id %u seq %u",
GET_BE_U_2(dp->icmp_id),
/*
* print the remnants of the IP packet.
- * save the snaplength as this may get overidden in the IP printer.
+ * save the snaplength as this may get overridden in the IP printer.
*/
if (ndo->ndo_vflag >= 1 && ICMP_ERRTYPE(icmp_type)) {
+ const u_char *snapend_save;
+
bp += 8;
ND_PRINT("\n\t");
ip = (const struct ip *)bp;
- snapend_save = ndo->ndo_snapend;
- ND_TCHECK_2(ip->ip_len);
+ snapend_save = ndo->ndo_snapend;
+ /*
+ * Update the snapend because extensions (MPLS, ...) may be
+ * present after the IP packet. In this case the current
+ * (outer) packet's snapend is not what ip_print() needs to
+ * decode an IP packet nested in the middle of an ICMP payload.
+ *
+ * This prevents that, in ip_print(), for the nested IP packet,
+ * the remaining length < remaining caplen.
+ */
+ ndo->ndo_snapend = ND_MIN(bp + GET_BE_U_2(ip->ip_len),
+ ndo->ndo_snapend);
ip_print(ndo, bp, GET_BE_U_2(ip->ip_len));
- ndo->ndo_snapend = snapend_save;
+ ndo->ndo_snapend = snapend_save;
}
/* ndo_protocol reassignment after ip_print() call */
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.
}
}
- 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;
}
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:
- ND_TCHECK_4(obj_tptr);
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));
}
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;
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