]> The Tcpdump Group git mirrors - tcpdump/commitdiff
Add dissector for ICMP Interface Identification Object
authorishaangandhi <[email protected]>
Tue, 24 Nov 2020 16:50:18 +0000 (11:50 -0500)
committerfxlb <[email protected]>
Tue, 13 Jul 2021 19:02:32 +0000 (19:02 +0000)
print-icmp.c
tests/TESTLIST
tests/icmp-cksum-oobr-2.out
tests/icmp-rfc5837.out [new file with mode: 0644]
tests/icmp-rfc5837.pcap [new file with mode: 0644]

index fe90aff0f3a3f391eb235226c96017fd8d3fb55a..6642c99078b309f71f818d0a851f4cd2f58bb049 100644 (file)
@@ -276,6 +276,42 @@ static const struct tok icmp_multipart_ext_obj_values[] = {
     { 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"},
+       { 0, NULL }
+};
+
+/*
+Interface IP Address Sub-Object
+0                            31
++-------+-------+-------+-------+
+|      AFI      |    Reserved   |
++-------+-------+-------+-------+
+|         IP Address   ....
+*/
+struct icmp_interface_identification_ipaddr_subobject_t {
+    nd_uint16_t  afi;
+    nd_uint16_t  reserved;
+    nd_uint32_t  ip_addr;
+};
+
+/*
+Interface Name Sub-Object
+octet    0        1                                   63
+        +--------+-----------................-----------------+
+        | length |   interface name octets 1-63               |
+        +--------+-----------................-----------------+
+*/
+struct icmp_interface_identification_ifname_subobject_t {
+    nd_uint8_t  length;
+    nd_byte     if_name[63];
+};
+
+
 /* prototypes */
 const char *icmp_tstamp_print(u_int);
 
@@ -311,6 +347,10 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
         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;
        char buf[MAXHOSTNAMELEN + 100];
@@ -751,7 +791,7 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
                 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);
@@ -765,11 +805,64 @@ 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:
+                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;
index 05a326e446f3c29d9471eceab93d028af155d3b8..8fa5d7898e96972f4dd7d7a23008c4c04befc076 100644 (file)
@@ -186,6 +186,9 @@ igmpv3-queries  igmpv3-queries.pcap     igmpv3-queries.out
 mtrace         mtrace.pcap             mtrace.out
 dvmrp          mrinfo_query.pcap       dvmrp.out
 
+# ICMPv4 -- pcap from https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=6632
+rfc5837    icmp-rfc5837.pcap icmp-rfc5837.out -v
+
 # ICMPv6
 icmpv6          icmpv6.pcap             icmpv6.out      -vv
 icmpv6_opt24-v icmpv6_opt24.pcap       icmpv6_opt24-v.out      -v
index ce5fc1416d6c7128906a5b3f153d312823960eb3..c83905c46cb57807ea2c65c49f601c9b41349211 100644 (file)
@@ -2,10 +2,9 @@
     10.4.0.34 > 12.4.4.4: ICMP time exceeded in-transit, length 32988
        (tos 0x0, ttl 1, id 42321, offset 0, flags [none], proto UDP (17), length 40)
     12.4.4.4.42315 > 12.1.1.1.33440: [bad udp cksum 0x1000 -> 0xbad0!] UDP, length 12
-           0x0000:  0000 000f 0001 0000 0a0a 0a0a 3f54 6869
-           0x0010:  732d 6973 2d74 6865 2d6e 616d 652d 6f66
-           0x0020:  2d74 6865 2d49 6e74 6572 6661 6365 2d74
-           0x0030:  6861 742d 7765 2d61 7265 2d6c 6f6f 6b69
-           0x0040:  6e67 2d66 6f72 2d5b 3a2d 295d [|icmp]
        ICMP Multi-Part extension v2
          Interface Identification Object (2), Class-Type: 14, length 80
+                This object describes the IP interface upon which a datagram arrived
+                Interface Index: 15
+                IP Address sub-object: 10.10.10.10
+                Interface Name: This-is-the-name-of-the-Interface-that-we-are-looking-for-[:-)] [|icmp]
diff --git a/tests/icmp-rfc5837.out b/tests/icmp-rfc5837.out
new file mode 100644 (file)
index 0000000..bc6cd08
--- /dev/null
@@ -0,0 +1,10 @@
+    1  10:13:29.331681 IP (tos 0x0, ttl 254, id 59168, offset 0, flags [DF], proto ICMP (1), length 240)
+    10.4.0.2 > 12.4.4.4: ICMP time exceeded in-transit, length 220
+       IP (tos 0x0, ttl 1, id 42321, offset 0, flags [none], proto UDP (17), length 40)
+    12.4.4.4.42315 > 12.1.1.1.33440: UDP, length 12
+       ICMP Multi-Part extension v2, checksum 0x256c (correct), length 84
+         Interface Identification Object (2), Class-Type: 14, length 80
+                This object describes the IP interface upon which a datagram arrived
+                Interface Index: 15
+                IP Address sub-object: 10.10.10.10
+                Interface Name: This-is-the-name-of-the-Interface-that-we-are-looking-for-[:-)]
diff --git a/tests/icmp-rfc5837.pcap b/tests/icmp-rfc5837.pcap
new file mode 100644 (file)
index 0000000..5daa8e5
Binary files /dev/null and b/tests/icmp-rfc5837.pcap differ