Clean up the object abbreviation list.

Have the OID prefixes be arrays of uint8_t, and put the size of the
array into the list, rather than having them be "strings" and et the
length with strlen().

Have a macro to encapsulate X.690 section 8.19.4's rules for the first
octet of an OID value, and use it; that makes the components of the OID
clearer.

Also, if the prefix is longer than the remaining data in the OID - or
the remaining captured data - just skip it, don't treat that as an
error.

diff --git a/print-snmp.c b/print-snmp.c
index 3ca219016d89c600dc9c5b8787665fd9fc9e9b7f..d329f867969f46e777063f5a130a52d667fdd761 100644 (file)
--- a/print-snmp.c
+++ b/print-snmp.c
@@ -276,28 +276,46 @@ static struct obj {
  * Currently, this includes the prefixes for the Internet MIB, the
  * private enterprises tree, and the experimental tree.
  */
+#define OID_FIRST_OCTET(x, y)  (((x)*40) + (y))        /* X.690 8.19.4 */
+
+#ifndef NO_ABREV_MIB
+static const uint8_t mib_oid[] = { OID_FIRST_OCTET(1, 3), 6, 1, 2, 1 };
+#endif
+#ifndef NO_ABREV_ENTER
+static const uint8_t enterprises_oid[] = { OID_FIRST_OCTET(1, 3), 6, 1, 4, 1 };
+#endif
+#ifndef NO_ABREV_EXPERI
+static const uint8_t experimental_oid[] = { OID_FIRST_OCTET(1, 3), 6, 1, 3 };
+#endif
+#ifndef NO_ABBREV_SNMPMODS
+static const uint8_t snmpModules_oid[] = { OID_FIRST_OCTET(1, 3), 6, 1, 6, 3 };
+#endif
+
+#define OBJ_ABBREV_ENTRY(prefix, obj) \
+       { prefix, &_ ## obj ## _obj, obj ## _oid, sizeof (obj ## _oid) }
 static const struct obj_abrev {
        const char *prefix;             /* prefix for this abrev */
        struct obj *node;               /* pointer into object table */
-       const char *oid;                /* ASN.1 encoded OID */
+       const uint8_t *oid;             /* ASN.1 encoded OID */
+       size_t oid_len;                 /* length of OID */
 } obj_abrev_list[] = {
 #ifndef NO_ABREV_MIB
        /* .iso.org.dod.internet.mgmt.mib */
-       { "",   &_mib_obj,              "\53\6\1\2\1" },
+       OBJ_ABBREV_ENTRY("",    mib),
 #endif
 #ifndef NO_ABREV_ENTER
        /* .iso.org.dod.internet.private.enterprises */
-       { "E:", &_enterprises_obj,      "\53\6\1\4\1" },
+       OBJ_ABBREV_ENTRY("E:",  enterprises),
 #endif
 #ifndef NO_ABREV_EXPERI
        /* .iso.org.dod.internet.experimental */
-       { "X:", &_experimental_obj,     "\53\6\1\3" },
+       OBJ_ABBREV_ENTRY("X:",  experimental),
 #endif
 #ifndef NO_ABBREV_SNMPMODS
        /* .iso.org.dod.internet.snmpV2.snmpModules */
-        { "S:", &_snmpModules_obj,      "\53\6\1\6\3" },
+       OBJ_ABBREV_ENTRY("S:",  snmpModules),
 #endif
-       { 0,0,0 }
+       { 0,0,0,0 }
 };
 
 /*
@@ -737,14 +755,14 @@ asn1_print(netdissect_options *ndo,
                        if (!ndo->ndo_nflag && asnlen > 2) {
                                const struct obj_abrev *a = &obj_abrev_list[0];
                                for (; a->node; a++) {
-                                       size_t a_len = strlen(a->oid);
-                                       ND_TCHECK2(*p, a_len);
-                                       if (memcmp(a->oid, p, a_len) == 0) {
+                                       if (i < a->oid_len)
+                                               continue;
+                                       if (!ND_TTEST2(*p, a->oid_len))
+                                               continue;
+                                       if (memcmp(a->oid, p, a->oid_len) == 0) {
                                                objp = a->node->child;
-                                               if (i < a_len)
-                                                       goto trunc;
-                                               i -= a_len;
-                                               p += a_len;
+                                               i -= a->oid_len;
+                                               p += a->oid_len;
                                                ND_PRINT((ndo, "%s", a->prefix));
                                                first = 1;
                                                break;