From Stefan Metzmacher and Gregor Beck via https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=5850 :

The smallest LDAP PDU is 7 bytes, not 4.

svn path=/trunk/; revision=36777

2 files changed, 64 insertions, 6 deletions

diff --git a/asn1/ldap/packet-ldap-template.c b/asn1/ldap/packet-ldap-template.c
index 74dffda805..681eda11ab 100644
--- a/asn1/ldap/packet-ldap-template.c
+++ b/asn1/ldap/packet-ldap-template.c
@@ -1705,7 +1705,36 @@ this_was_not_sasl:
 		goto this_was_not_normal_ldap;
 	}
 
-	tcp_dissect_pdus(tvb, pinfo, tree, ldap_desegment, 4, get_normal_ldap_pdu_len, dissect_normal_ldap_pdu);
+	/*
+	 * The minimun size of a LDAP pdu is 7 bytes
+	 *
+	 * dumpasn1 -hh ldap-unbind-min.dat
+	 *
+	 *     <30 05 02 01 09 42 00>
+	 *    0    5: SEQUENCE {
+	 *     <02 01 09>
+	 *    2    1:   INTEGER 9
+	 *     <42 00>
+	 *    5    0:   [APPLICATION 2]
+	 *          :     Error: Object has zero length.
+	 *          :   }
+	 *
+	 * dumpasn1 -hh ldap-unbind-windows.dat
+	 *
+	 *     <30 84 00 00 00 05 02 01 09 42 00>
+	 *    0    5: SEQUENCE {
+	 *     <02 01 09>
+	 *    6    1:   INTEGER 9
+	 *     <42 00>
+	 *    9    0:   [APPLICATION 2]
+	 *          :     Error: Object has zero length.
+	 *          :   }
+	 *
+	 * 6 bytes would also be ok to get the full length of
+	 * the pdu, but as the smallest pdu can be 7 bytes
+	 * we can use 7.
+	 */
+	tcp_dissect_pdus(tvb, pinfo, tree, ldap_desegment, 7, get_normal_ldap_pdu_len, dissect_normal_ldap_pdu);
 
 	goto end;
 
diff --git a/epan/dissectors/packet-ldap.c b/epan/dissectors/packet-ldap.c
index a660d5e4b0..011a641860 100644
--- a/epan/dissectors/packet-ldap.c
+++ b/epan/dissectors/packet-ldap.c
@@ -1,7 +1,7 @@
 /* Do not modify this file.                                                   */
 /* It is created automatically by the ASN.1 to Wireshark dissector compiler   */
 /* packet-ldap.c                                                              */
-/* ../../tools/asn2wrs.py -b -p ldap -c ./ldap.cnf -s ./packet-ldap-template -D . Lightweight-Directory-Access-Protocol-V3.asn */
+/* ../../../tools/asn2wrs.py -b -p ldap -c ../../../asn1/ldap/ldap.cnf -s ../../../asn1/ldap/packet-ldap-template -D ../../../asn1/ldap Lightweight-Directory-Access-Protocol-V3.asn */
 
 /* Input file: packet-ldap-template.c */
 
@@ -4669,7 +4669,36 @@ this_was_not_sasl:
 		goto this_was_not_normal_ldap;
 	}
 
-	tcp_dissect_pdus(tvb, pinfo, tree, ldap_desegment, 4, get_normal_ldap_pdu_len, dissect_normal_ldap_pdu);
+	/*
+	 * The minimun size of a LDAP pdu is 7 bytes
+	 *
+	 * dumpasn1 -hh ldap-unbind-min.dat
+	 *
+	 *     <30 05 02 01 09 42 00>
+	 *    0    5: SEQUENCE {
+	 *     <02 01 09>
+	 *    2    1:   INTEGER 9
+	 *     <42 00>
+	 *    5    0:   [APPLICATION 2]
+	 *          :     Error: Object has zero length.
+	 *          :   }
+	 *
+	 * dumpasn1 -hh ldap-unbind-windows.dat
+	 *
+	 *     <30 84 00 00 00 05 02 01 09 42 00>
+	 *    0    5: SEQUENCE {
+	 *     <02 01 09>
+	 *    6    1:   INTEGER 9
+	 *     <42 00>
+	 *    9    0:   [APPLICATION 2]
+	 *          :     Error: Object has zero length.
+	 *          :   }
+	 *
+	 * 6 bytes would also be ok to get the full length of
+	 * the pdu, but as the smallest pdu can be 7 bytes
+	 * we can use 7.
+	 */
+	tcp_dissect_pdus(tvb, pinfo, tree, ldap_desegment, 7, get_normal_ldap_pdu_len, dissect_normal_ldap_pdu);
 
 	goto end;
 
@@ -5583,7 +5612,7 @@ void proto_register_ldap(void) {
         NULL, HFILL }},
 
 /*--- End of included file: packet-ldap-hfarr.c ---*/
-#line 2042 "../../asn1/ldap/packet-ldap-template.c"
+#line 2071 "../../asn1/ldap/packet-ldap-template.c"
   };
 
   /* List of subtrees */
@@ -5658,7 +5687,7 @@ void proto_register_ldap(void) {
     &ett_ldap_T_warning,
 
 /*--- End of included file: packet-ldap-ettarr.c ---*/
-#line 2055 "../../asn1/ldap/packet-ldap-template.c"
+#line 2084 "../../asn1/ldap/packet-ldap-template.c"
   };
 
     module_t *ldap_module;
@@ -5789,7 +5818,7 @@ proto_reg_handoff_ldap(void)
 
 
 /*--- End of included file: packet-ldap-dis-tab.c ---*/
-#line 2169 "../../asn1/ldap/packet-ldap-template.c"
+#line 2198 "../../asn1/ldap/packet-ldap-template.c"
 
 
 }