]> The Tcpdump Group git mirrors - tcpdump/blobdiff - print-icmp.c
RADIUS: Rename a test with an invalid length
[tcpdump] / print-icmp.c
index 4e66a3cff96c8928c47cfa4475720ddde70fee09..074d937716c3927811eb53987f027ce84bd2e503 100644 (file)
@@ -86,9 +86,6 @@ 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 +185,6 @@ 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 +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.
@@ -264,6 +260,32 @@ 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;
@@ -748,7 +770,7 @@ 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;
             }
@@ -853,11 +875,23 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
 
                         ifname_subobj = (const struct icmp_interface_identification_ifname_subobject_t *) offset;
                         inft_name_length_field = GET_U_1(ifname_subobj->length);
-                        ND_PRINT("\n\t\t Interface Name, length %u: %.*s",
-                                 inft_name_length_field,
-                                 inft_name_length_field,
-                                 ifname_subobj->if_name);
-                        offset += 1 + inft_name_length_field;
+                        ND_PRINT("\n\t\t Interface Name");
+                        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\t MTU: %u", GET_BE_U_4(offset));