Add a routine to "asn1.c" to translate ASN1_ERR_ values to strings. Use

that in the SNMP dissector.

Check the return values of ASN.1 routines in the LDAP dissector, and
have all the subroutines in that disesctor that can return error
indications return ASN1_ERR_ values.

Have the routines that can supply a pointer to a newly-created
protocol-tree item use the right type for items ("proto_item *", not
"proto_tree *", even though they are, at least currently, typedefs for
the same type), and use "proto_item" for the type of the item a pointer
to which is passed to those routines.

Before calling those routines, set the item pointer to null, in case the
routine fails.

Don't check the return value of "parse_filter_strings()" against -1 -
that routine can't return -1.

svn path=/trunk/; revision=4833

4 files changed, 348 insertions, 174 deletions

diff --git a/asn1.c b/asn1.c
index 4570c0da22..e7cf347832 100644
--- a/asn1.c
+++ b/asn1.c
@@ -1,7 +1,7 @@
 /* asn1.c
  * Routines for ASN.1 BER dissection
  *
- * $Id: asn1.c,v 1.10 2002/02/21 02:05:53 guy Exp $
+ * $Id: asn1.c,v 1.11 2002/03/01 02:48:10 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -60,6 +60,8 @@
 # include "config.h"
 #endif
 
+#include <stdio.h>
+
 #ifdef HAVE_SYS_TYPES_H
 # include <sys/types.h>
 #endif
@@ -71,6 +73,11 @@
 #include <limits.h>
 
 #include <glib.h>
+
+#ifdef NEED_SNPRINTF_H
+# include "snprintf.h"
+#endif
+
 #include <epan/tvbuff.h>
 #include "asn1.h"
 
@@ -970,3 +977,50 @@ done:
     *nbytes = asn1->offset - start;
     return ret;
 }
+
+/*
+ * NAME:        asn1_err_to_str                             [API]
+ * SYNOPSIS:    char *asn1_err_to_str
+ *                  (
+ *                      int     err
+ *                  )
+ * DESCRIPTION: Returns the string corresponding to an ASN.1 library error.
+ *              Parameters:
+ *              err: the error code
+ * RETURNS:     string for the error
+ */
+char *
+asn1_err_to_str(int err)
+{
+    char         *errstr;
+    char         errstrbuf[14+1+1+11+1+1];	/* "Unknown error (%d)\0" */
+
+    switch (err) {
+
+    case ASN1_ERR_EOC_MISMATCH:
+	errstr = "EOC mismatch";
+	break;
+
+    case ASN1_ERR_WRONG_TYPE:
+	errstr = "Wrong type for that item";
+	break;
+
+    case ASN1_ERR_LENGTH_NOT_DEFINITE:
+	errstr = "Length was indefinite";
+	break;
+
+    case ASN1_ERR_LENGTH_MISMATCH:
+	errstr = "Length mismatch";
+	break;
+
+    case ASN1_ERR_WRONG_LENGTH_FOR_TYPE:
+	errstr = "Wrong length for that item's type";
+	break;
+
+    default:
+	snprintf(errstrbuf, sizeof errstrbuf, "Unknown error (%d)", err);
+	errstr = errstrbuf;
+	break;
+    }
+    return errstr;
+}
diff --git a/asn1.h b/asn1.h
index 1befdfc9c7..d6125ba880 100644
--- a/asn1.h
+++ b/asn1.h
@@ -1,10 +1,10 @@
 /* asn1.h
  * Definitions for ASN.1 BER dissection
  *
- * $Id: asn1.h,v 1.5 2001/04/15 07:30:02 guy Exp $
+ * $Id: asn1.h,v 1.6 2002/03/01 02:48:10 guy Exp $
  *
  * Ethereal - Network traffic analyzer
- * By Gerald Combs <gerald@zing.org>
+ * By Gerald Combs <gerald@ethereal.com>
  *
  * Based on "g_asn1.h" from:
  *
@@ -140,4 +140,7 @@ int asn1_oid_value_decode (ASN1_SCK *asn1, int enc_len, subid_t **oid,
 			guint *len);
 int asn1_oid_decode ( ASN1_SCK *asn1, subid_t **oid, guint *len, guint *nbytes);
 int asn1_sequence_decode ( ASN1_SCK *asn1, guint *seq_len, guint *nbytes);
+
+char *asn1_err_to_str (int err);
+
 #endif
diff --git a/packet-ldap.c b/packet-ldap.c
index 87c0a2e646..af4a56a191 100644
--- a/packet-ldap.c
+++ b/packet-ldap.c
@@ -1,7 +1,7 @@
 /* packet-ldap.c
  * Routines for ldap packet dissection
  *
- * $Id: packet-ldap.c,v 1.34 2002/01/24 09:20:49 guy Exp $
+ * $Id: packet-ldap.c,v 1.35 2002/03/01 02:48:10 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -145,8 +145,11 @@ static int read_length(ASN1_SCK *a, proto_tree *tree, int hf_id, guint *len)
   guint length = 0;
   gboolean def = FALSE;
   int start = a->offset;
+  int ret;
   
-  asn1_length_decode(a, &def, &length);
+  ret = asn1_length_decode(a, &def, &length);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
 
   if (len)
     *len = length;
@@ -154,7 +157,7 @@ static int read_length(ASN1_SCK *a, proto_tree *tree, int hf_id, guint *len)
   if (tree)
     proto_tree_add_uint(tree, hf_id, a->tvb, start, a->offset-start, length);
 
-  return 0;
+  return ASN1_ERR_NOERROR;
 }
 
 static int read_sequence(ASN1_SCK *a, guint *len)
@@ -162,16 +165,18 @@ static int read_sequence(ASN1_SCK *a, guint *len)
   guint cls, con, tag;
   gboolean def;
   guint length;
+  int ret;
   
-  if (asn1_header_decode(a, &cls, &con, &tag, &def, &length) != ASN1_ERR_NOERROR)
-    return 1;
+  ret = asn1_header_decode(a, &cls, &con, &tag, &def, &length);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
   if (cls != ASN1_UNI || con != ASN1_CON || tag != ASN1_SEQ)
-    return 1;
+    return ASN1_ERR_WRONG_TYPE;
 
   if (len)
     *len = length;
   
-  return 0;
+  return ASN1_ERR_NOERROR;
 }
 
 static int read_set(ASN1_SCK *a, guint *len)
@@ -179,57 +184,65 @@ static int read_set(ASN1_SCK *a, guint *len)
   guint cls, con, tag;
   gboolean def;
   guint length;
+  int ret;
   
-  if (asn1_header_decode(a, &cls, &con, &tag, &def, &length) != ASN1_ERR_NOERROR)
-    return 1;
+  ret = asn1_header_decode(a, &cls, &con, &tag, &def, &length);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
   if (cls != ASN1_UNI || con != ASN1_CON || tag != ASN1_SET)
-    return 1;
+    return ASN1_ERR_WRONG_TYPE;
   
   if (len)
     *len = length;
   
-  return 0;
+  return ASN1_ERR_NOERROR;
 }
 
 static int read_integer_value(ASN1_SCK *a, proto_tree *tree, int hf_id,
-	proto_tree **new_tree, guint *i, int start, guint length)
+	proto_item **new_item, guint *i, int start, guint length)
 {
   guint integer = 0;
+  int ret;
 
-  asn1_uint32_value_decode(a, length, &integer);
+  ret = asn1_uint32_value_decode(a, length, &integer);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
 
   if (i)
     *i = integer;
 
   if (tree)
   {
-    proto_tree *temp_tree = 0;
-    temp_tree = proto_tree_add_uint(tree, hf_id, a->tvb, start, a->offset-start, integer);
-    if (new_tree)
-      *new_tree = temp_tree;
+    proto_tree *temp_item;
+
+    temp_item = proto_tree_add_uint(tree, hf_id, a->tvb, start, a->offset-start, integer);
+    if (new_item)
+      *new_item = temp_item;
   }
 
-  return 0;
+  return ASN1_ERR_NOERROR;
 }
 
 static int read_integer(ASN1_SCK *a, proto_tree *tree, int hf_id,
-	proto_tree **new_tree, guint *i, guint expected_tag)
+	proto_item **new_item, guint *i, guint expected_tag)
 {
   guint cls, con, tag;
   gboolean def;
   guint length;
   int start = a->offset;
+  int ret;
   
-  if (asn1_header_decode(a, &cls, &con, &tag, &def, &length) != ASN1_ERR_NOERROR)
-    return 1;
+  ret = asn1_header_decode(a, &cls, &con, &tag, &def, &length);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
   if (cls != ASN1_UNI || con != ASN1_PRI || tag != expected_tag)
-    return 1;
+    return ASN1_ERR_WRONG_TYPE;
 
-  return read_integer_value(a, tree, hf_id, new_tree, i, start, length);
+  return read_integer_value(a, tree, hf_id, new_item, i, start, length);
 }
 
 static int read_boolean_value(ASN1_SCK *a, proto_tree *tree, int hf_id,
-	proto_tree **new_tree, guint *i, int start, guint length)
+	proto_item **new_item, guint *i, int start, guint length)
 {
   guint integer = 0;
 
@@ -240,39 +253,45 @@ static int read_boolean_value(ASN1_SCK *a, proto_tree *tree, int hf_id,
 
   if (tree)
   {
-    proto_tree *temp_tree = 0;
-    temp_tree = proto_tree_add_boolean(tree, hf_id, a->tvb, start, a->offset-start, integer);
-    if (new_tree)
-      *new_tree = temp_tree;
+    proto_item *temp_item;
+
+    temp_item = proto_tree_add_boolean(tree, hf_id, a->tvb, start, a->offset-start, integer);
+    if (new_item)
+      *new_item = temp_item;
   }
 
-  return 0;
+  return ASN1_ERR_NOERROR;
 }
 
 static int read_boolean(ASN1_SCK *a, proto_tree *tree, int hf_id,
-	proto_tree **new_tree, guint *i)
+	proto_item **new_item, guint *i)
 {
   guint cls, con, tag;
   gboolean def;
   guint length;
   int start = a->offset;
+  int ret;
   
-  if (asn1_header_decode(a, &cls, &con, &tag, &def, &length) != ASN1_ERR_NOERROR)
-    return 1;
+  ret = asn1_header_decode(a, &cls, &con, &tag, &def, &length);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
   if (cls != ASN1_UNI || con != ASN1_PRI || tag != ASN1_BOL)
-    return 1;
+    return ASN1_ERR_WRONG_TYPE;
 
-  return read_boolean_value(a, tree, hf_id, new_tree, i, start, length);
+  return read_boolean_value(a, tree, hf_id, new_item, i, start, length);
 }
 
-static void read_string_value(ASN1_SCK *a, proto_tree *tree, int hf_id,
-	proto_tree **new_tree, char **s, int start, guint length)
+static int read_string_value(ASN1_SCK *a, proto_tree *tree, int hf_id,
+	proto_item **new_item, char **s, int start, guint length)
 {
   guchar *string;
+  int ret;
   
   if (length)
   {
-    asn1_string_value_decode(a, length, &string);
+    ret = asn1_string_value_decode(a, length, &string);
+    if (ret != ASN1_ERR_NOERROR)
+      return ret;
     string = g_realloc(string, length + 1);
     string[length] = '\0';
   }
@@ -281,20 +300,23 @@ static void read_string_value(ASN1_SCK *a, proto_tree *tree, int hf_id,
     
   if (tree)
   {
-    proto_tree *temp_tree;
-    temp_tree = proto_tree_add_string(tree, hf_id, a->tvb, start, a->offset - start, string);
-    if (new_tree)
-      *new_tree = temp_tree;
+    proto_item *temp_item;
+
+    temp_item = proto_tree_add_string(tree, hf_id, a->tvb, start, a->offset - start, string);
+    if (new_item)
+      *new_item = temp_item;
   }
 
   if (s && length)
     *s = string;
   else if (length)
     g_free(string);
+
+  return ASN1_ERR_NOERROR;
 }
 
 static int read_string(ASN1_SCK *a, proto_tree *tree, int hf_id,
-	proto_tree **new_tree, char **s, guint expected_cls, guint expected_tag)
+	proto_item **new_item, char **s, guint expected_cls, guint expected_tag)
 {
   guint cls, con, tag;
   gboolean def;
@@ -308,8 +330,7 @@ static int read_string(ASN1_SCK *a, proto_tree *tree, int hf_id,
   if (cls != expected_cls || con != ASN1_PRI || tag != expected_tag)
     return ASN1_ERR_WRONG_TYPE;
 
-  read_string_value(a, tree, hf_id, new_tree, s, start, length);
-  return ASN1_ERR_NOERROR;
+  return read_string_value(a, tree, hf_id, new_item, s, start, length);
 }
 
 static int parse_filter_strings(ASN1_SCK *a, char **filter, guint *filter_length, const guchar *operation)
@@ -529,14 +550,14 @@ static int parse_filter(ASN1_SCK *a, char **filter, guint *filter_length,
       if (con != ASN1_CON)
         return ASN1_ERR_WRONG_TYPE;
       ret = parse_filter_strings(a, filter, filter_length, "=");
-      if (ret != -1 && ret != ASN1_ERR_NOERROR)
+      if (ret != ASN1_ERR_NOERROR)
         return ret;
       break;
      case LDAP_FILTER_GE:
       if (con != ASN1_CON)
         return ASN1_ERR_WRONG_TYPE;
       ret = parse_filter_strings(a, filter, filter_length, ">=");
-      if (ret != -1 && ret != ASN1_ERR_NOERROR)
+      if (ret != ASN1_ERR_NOERROR)
         return ret;
       break;
      case LDAP_FILTER_LE:
@@ -550,7 +571,7 @@ static int parse_filter(ASN1_SCK *a, char **filter, guint *filter_length,
       if (con != ASN1_CON)
         return ASN1_ERR_WRONG_TYPE;
       ret = parse_filter_strings(a, filter, filter_length, "~=");
-      if (ret != -1 && ret != ASN1_ERR_NOERROR)
+      if (ret != ASN1_ERR_NOERROR)
         return ret;
       break;
      case LDAP_FILTER_PRESENT:
@@ -583,7 +604,7 @@ static int parse_filter(ASN1_SCK *a, char **filter, guint *filter_length,
         return ASN1_ERR_WRONG_TYPE;
       /* Richard Dawe: Handle substrings */
       ret = parse_filter_substrings(a, filter, filter_length);
-      if (ret != -1 && ret != ASN1_ERR_NOERROR)
+      if (ret != ASN1_ERR_NOERROR)
         return ret;
       break;
      default:
@@ -612,14 +633,14 @@ static int read_filter(ASN1_SCK *a, proto_tree *tree, int hf_id)
   if (tree) {
     if (ret != -1) {
       proto_tree_add_text(tree, a->tvb, start, 0,
-        "Error parsing filter (%d)", ret);
+        "Error parsing filter: %s", asn1_err_to_str(ret));
     } else
       proto_tree_add_string(tree, hf_id, a->tvb, start, a->offset-start, filter);
   }
 
   g_free(filter);
 
-  return 0;
+  return (ret == -1) ? ASN1_ERR_NOERROR : ret;
 }
 
 /********************************************************************************************/
@@ -627,28 +648,41 @@ static int read_filter(ASN1_SCK *a, proto_tree *tree, int hf_id)
 static int dissect_ldap_result(ASN1_SCK *a, proto_tree *tree)
 {
   guint resultCode = 0;
+  int ret;
   
-  read_integer(a, tree, hf_ldap_message_result, 0, &resultCode, ASN1_ENUM);
-  read_string(a, tree, hf_ldap_message_result_matcheddn, 0, 0, ASN1_UNI, ASN1_OTS);
-  read_string(a, tree, hf_ldap_message_result_errormsg, 0, 0, ASN1_UNI, ASN1_OTS);
+  ret = read_integer(a, tree, hf_ldap_message_result, 0, &resultCode, ASN1_ENUM);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
+  ret = read_string(a, tree, hf_ldap_message_result_matcheddn, 0, 0, ASN1_UNI, ASN1_OTS);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
+  ret = read_string(a, tree, hf_ldap_message_result_errormsg, 0, 0, ASN1_UNI, ASN1_OTS);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
 
   if (resultCode == 10)		/* Referral */
   {
     int start = a->offset;
     int end;
     guint length;
-    proto_tree *t, *referralTree;
+    proto_item *ti;
+    proto_tree *referralTree;
     
-    read_sequence(a, &length);
-    t = proto_tree_add_text(tree, a->tvb, start, length, "Referral URLs");
-    referralTree = proto_item_add_subtree(t, ett_ldap_referrals);
+    ret = read_sequence(a, &length);
+    if (ret != ASN1_ERR_NOERROR)
+      return ret;
+    ti = proto_tree_add_text(tree, a->tvb, start, length, "Referral URLs");
+    referralTree = proto_item_add_subtree(ti, ett_ldap_referrals);
 
     end = a->offset + length;
-    while (a->offset < end)
-      read_string(a, referralTree, hf_ldap_message_result_referral, 0, 0, ASN1_UNI, ASN1_OTS);
+    while (a->offset < end) {
+      ret = read_string(a, referralTree, hf_ldap_message_result_referral, 0, 0, ASN1_UNI, ASN1_OTS);
+      if (ret != ASN1_ERR_NOERROR)
+        return ret;
+    }
   }
     
-  return 0;
+  return ASN1_ERR_NOERROR;
 }
 
 static int dissect_ldap_request_bind(ASN1_SCK *a, proto_tree *tree)
@@ -656,36 +690,43 @@ static int dissect_ldap_request_bind(ASN1_SCK *a, proto_tree *tree)
   guint cls, con, tag;
   guint def, length;
   int start;
+  int ret;
 
-  read_integer(a, tree, hf_ldap_message_bind_version, 0, 0, ASN1_INT);
-  read_string(a, tree, hf_ldap_message_bind_dn, 0, 0, ASN1_UNI, ASN1_OTS);
+  ret = read_integer(a, tree, hf_ldap_message_bind_version, 0, 0, ASN1_INT);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
+  ret = read_string(a, tree, hf_ldap_message_bind_dn, 0, 0, ASN1_UNI, ASN1_OTS);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
 
   start = a->offset;
-  if (asn1_header_decode(a, &cls, &con, &tag, &def, &length) != ASN1_ERR_NOERROR)
-    return 1;	/* XXX - right return value for an error? */
+  ret = asn1_header_decode(a, &cls, &con, &tag, &def, &length);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
   if (cls != ASN1_CTX)
-    return 1;	/* RFCs 1777 and 2251 say these are context-specific types */
+    return ASN1_ERR_WRONG_TYPE;	/* RFCs 1777 and 2251 say these are context-specific types */
   proto_tree_add_uint(tree, hf_ldap_message_bind_auth, a->tvb, start,
 			a->offset - start, tag);
   switch (tag)
   {
    case LDAP_AUTH_SIMPLE:
-    read_string_value(a, tree, hf_ldap_message_bind_auth_password, NULL, NULL,
-			start, length);
+    ret = read_string_value(a, tree, hf_ldap_message_bind_auth_password, NULL,
+			    NULL, start, length);
+    if (ret != ASN1_ERR_NOERROR)
+      return ret;
     break;
 
     /* For Kerberos V4, dissect it as a ticket. */
     /* For SASL, dissect it as SaslCredentials. */
   }
   
-  return 0;
+  return ASN1_ERR_NOERROR;
 }
 
 static int dissect_ldap_response_bind(ASN1_SCK *a, proto_tree *tree)
 {
-  dissect_ldap_result(a, tree);
   /* FIXME: handle SASL data */
-  return 0;
+  return dissect_ldap_result(a, tree);
 }
 
 static int dissect_ldap_request_search(ASN1_SCK *a, proto_tree *tree)
@@ -694,16 +735,30 @@ static int dissect_ldap_request_search(ASN1_SCK *a, proto_tree *tree)
   int end;
   int ret;
   
-  read_string(a, tree, hf_ldap_message_search_base, 0, 0, ASN1_UNI, ASN1_OTS);
-  read_integer(a, tree, hf_ldap_message_search_scope, 0, 0, ASN1_ENUM);
-  read_integer(a, tree, hf_ldap_message_search_deref, 0, 0, ASN1_ENUM);
-  read_integer(a, tree, hf_ldap_message_search_sizeLimit, 0, 0, ASN1_INT);
-  read_integer(a, tree, hf_ldap_message_search_timeLimit, 0, 0, ASN1_INT);
-  read_boolean(a, tree, hf_ldap_message_search_typesOnly, 0, 0);
+  ret = read_string(a, tree, hf_ldap_message_search_base, 0, 0, ASN1_UNI, ASN1_OTS);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
+  ret = read_integer(a, tree, hf_ldap_message_search_scope, 0, 0, ASN1_ENUM);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
+  ret = read_integer(a, tree, hf_ldap_message_search_deref, 0, 0, ASN1_ENUM);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
+  ret = read_integer(a, tree, hf_ldap_message_search_sizeLimit, 0, 0, ASN1_INT);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
+  ret = read_integer(a, tree, hf_ldap_message_search_timeLimit, 0, 0, ASN1_INT);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
+  ret = read_boolean(a, tree, hf_ldap_message_search_typesOnly, 0, 0);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
   ret = read_filter(a, tree, hf_ldap_message_search_filter);
   if (ret != ASN1_ERR_NOERROR)
     return ret;
-  read_sequence(a, &seq_length);
+  ret = read_sequence(a, &seq_length);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
   end = a->offset + seq_length;
   while (a->offset < end) {
     ret = read_string(a, tree, hf_ldap_message_attribute, 0, 0, ASN1_UNI, ASN1_OTS);
@@ -717,80 +772,120 @@ static int dissect_ldap_response_search_entry(ASN1_SCK *a, proto_tree *tree)
 {
   guint seq_length;
   int end_of_sequence;
+  int ret;
  
-  read_string(a, tree, hf_ldap_message_dn, 0, 0, ASN1_UNI, ASN1_OTS);
-  read_sequence(a, &seq_length);
+  ret = read_string(a, tree, hf_ldap_message_dn, 0, 0, ASN1_UNI, ASN1_OTS);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
+  ret = read_sequence(a, &seq_length);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
 
   end_of_sequence = a->offset + seq_length;
   while (a->offset < end_of_sequence)
   {
-    proto_tree *t, *attr_tree;
+    proto_item *ti;
+    proto_tree *attr_tree;
     guint set_length;
     int end_of_set;
 
-    read_sequence(a, 0);
-    read_string(a, tree, hf_ldap_message_attribute, &t, 0, ASN1_UNI, ASN1_OTS);
-    attr_tree = proto_item_add_subtree(t, ett_ldap_attribute);
+    ret = read_sequence(a, 0);
+    if (ret != ASN1_ERR_NOERROR)
+      return ret;
+    ti = NULL;
+    ret = read_string(a, tree, hf_ldap_message_attribute, &ti, 0, ASN1_UNI, ASN1_OTS);
+    if (ret != ASN1_ERR_NOERROR)
+      return ret;
+    attr_tree = proto_item_add_subtree(ti, ett_ldap_attribute);
 
-    read_set(a, &set_length);
+    ret = read_set(a, &set_length);
+    if (ret != ASN1_ERR_NOERROR)
+      return ret;
     end_of_set = a->offset + set_length;
-    while (a->offset < end_of_set)
-      read_string(a, attr_tree, hf_ldap_message_value, 0, 0, ASN1_UNI, ASN1_OTS);
+    while (a->offset < end_of_set) {
+      ret = read_string(a, attr_tree, hf_ldap_message_value, 0, 0, ASN1_UNI, ASN1_OTS);
+      if (ret != ASN1_ERR_NOERROR)
+        return ret;
+    }
   }
 
-  return 0;
+  return ASN1_ERR_NOERROR;
 }
 
 static int dissect_ldap_request_add(ASN1_SCK *a, proto_tree *tree)
 {
   guint seq_length;
   int end_of_sequence;
+  int ret;
   
-  read_string(a, tree, hf_ldap_message_dn, 0, 0, ASN1_UNI, ASN1_OTS);
+  ret = read_string(a, tree, hf_ldap_message_dn, 0, 0, ASN1_UNI, ASN1_OTS);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
 
-  read_sequence(a, &seq_length);
+  ret = read_sequence(a, &seq_length);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
   end_of_sequence = a->offset + seq_length;
   while (a->offset < end_of_sequence)
   {
-    proto_tree *t, *attr_tree;
+    proto_item *ti;
+    proto_tree *attr_tree;
     guint set_length;
     int end_of_set;
 
-    read_sequence(a, 0);
-    read_string(a, tree, hf_ldap_message_attribute, &t, 0, ASN1_UNI, ASN1_OTS);
-    attr_tree = proto_item_add_subtree(t, ett_ldap_attribute);
+    ret = read_sequence(a, 0);
+    if (ret != ASN1_ERR_NOERROR)
+      return ret;
+    ti = NULL;
+    ret = read_string(a, tree, hf_ldap_message_attribute, &ti, 0, ASN1_UNI, ASN1_OTS);
+    if (ret != ASN1_ERR_NOERROR)
+      return ret;
+    attr_tree = proto_item_add_subtree(ti, ett_ldap_attribute);
 
-    read_set(a, &set_length);
+    ret = read_set(a, &set_length);
+    if (ret != ASN1_ERR_NOERROR)
+      return ret;
     end_of_set = a->offset + set_length;
-    while (a->offset < end_of_set)
-      read_string(a, attr_tree, hf_ldap_message_value, 0, 0, ASN1_UNI, ASN1_OTS);
+    while (a->offset < end_of_set) {
+      ret = read_string(a, attr_tree, hf_ldap_message_value, 0, 0, ASN1_UNI, ASN1_OTS);
+      if (ret != ASN1_ERR_NOERROR)
+        return ret;
+    }
   }
 
-  return 0;
+  return ASN1_ERR_NOERROR;
 }
 
 static int dissect_ldap_request_delete(ASN1_SCK *a, proto_tree *tree,
 		int start, guint length)
 {
-  read_string_value(a, tree, hf_ldap_message_dn, NULL, NULL, start, length);
-  return 0;
+  return read_string_value(a, tree, hf_ldap_message_dn, NULL, NULL, start, length);
 }
 
 static int dissect_ldap_request_modifyrdn(ASN1_SCK *a, proto_tree *tree,
 		guint length)
 {
   int start = a->offset;
+  int ret;
 
-  read_string(a, tree, hf_ldap_message_dn, 0, 0, ASN1_UNI, ASN1_OTS);
-  read_string(a, tree, hf_ldap_message_modrdn_name, 0, 0, ASN1_UNI, ASN1_OTS);
-  read_boolean(a, tree, hf_ldap_message_modrdn_delete, 0, 0);
+  ret = read_string(a, tree, hf_ldap_message_dn, 0, 0, ASN1_UNI, ASN1_OTS);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
+  ret = read_string(a, tree, hf_ldap_message_modrdn_name, 0, 0, ASN1_UNI, ASN1_OTS);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
+  ret = read_boolean(a, tree, hf_ldap_message_modrdn_delete, 0, 0);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
   
   if (a->offset < (int) (start + length)) {
     /* LDAP V3 Modify DN operation, with newSuperior */
-    read_string(a, tree, hf_ldap_message_modrdn_superior, 0, 0, ASN1_UNI, ASN1_OTS);
+    ret = read_string(a, tree, hf_ldap_message_modrdn_superior, 0, 0, ASN1_UNI, ASN1_OTS);
+    if (ret != ASN1_ERR_NOERROR)
+      return ret;
   }
 
-  return 0;
+  return ASN1_ERR_NOERROR;
 }
 
 static int dissect_ldap_request_compare(ASN1_SCK *a, proto_tree *tree)
@@ -800,16 +895,22 @@ static int dissect_ldap_request_compare(ASN1_SCK *a, proto_tree *tree)
   char *string1 = 0;
   char *string2 = 0;
   char *compare;
+  int ret;
   
-  read_string(a, tree, hf_ldap_message_dn, 0, 0, ASN1_UNI, ASN1_OTS);
-  read_sequence(a, 0);
+  ret = read_string(a, tree, hf_ldap_message_dn, 0, 0, ASN1_UNI, ASN1_OTS);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
+  ret = read_sequence(a, 0);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
 
   start = a->offset;
-  read_string(a, 0, -1, 0, &string1, ASN1_UNI, ASN1_OTS);
-  read_string(a, 0, -1, 0, &string2, ASN1_UNI, ASN1_OTS);
-
-  if (string1 == 0 && string2 == 0) /* read_string failed */
-    return 1;
+  ret = read_string(a, 0, -1, 0, &string1, ASN1_UNI, ASN1_OTS);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
+  ret = read_string(a, 0, -1, 0, &string2, ASN1_UNI, ASN1_OTS);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
 
   length = 2 + strlen(string1) + strlen(string2);
   compare = g_malloc0(length);
@@ -821,57 +922,80 @@ static int dissect_ldap_request_compare(ASN1_SCK *a, proto_tree *tree)
   g_free(string2);
   g_free(compare);
   
-  return 0;
+  return ASN1_ERR_NOERROR;
 }
 
 static int dissect_ldap_request_modify(ASN1_SCK *a, proto_tree *tree)
 {
   guint seq_length;
   int end_of_sequence;
+  int ret;
   
-  read_string(a, tree, hf_ldap_message_dn, 0, 0, ASN1_UNI, ASN1_OTS);
-  read_sequence(a, &seq_length);
+  ret = read_string(a, tree, hf_ldap_message_dn, 0, 0, ASN1_UNI, ASN1_OTS);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
+  ret = read_sequence(a, &seq_length);
+  if (ret != ASN1_ERR_NOERROR)
+    return ret;
   end_of_sequence = a->offset + seq_length;
   while (a->offset < end_of_sequence)
   {
-    proto_tree *t = 0, *attr_tree;
+    proto_item *ti;
+    proto_tree *attr_tree;
     guint set_length;
     int end_of_set;
     guint operation;
 
-    read_sequence(a, 0);
-    read_integer(a, 0, -1, 0, &operation, ASN1_ENUM);
-    read_sequence(a, 0);
+    ret = read_sequence(a, 0);
+    if (ret != ASN1_ERR_NOERROR)
+      return ret;
+    ret = read_integer(a, 0, -1, 0, &operation, ASN1_ENUM);
+    if (ret != ASN1_ERR_NOERROR)
+      return ret;
+    ret = read_sequence(a, 0);
+    if (ret != ASN1_ERR_NOERROR)
+      return ret;
 
+    ti = NULL;
     switch (operation)
     {
      case LDAP_MOD_ADD:
-      read_string(a, tree, hf_ldap_message_modify_add, &t, 0, ASN1_UNI, ASN1_OTS);
+      ret = read_string(a, tree, hf_ldap_message_modify_add, &ti, 0, ASN1_UNI, ASN1_OTS);
+      if (ret != ASN1_ERR_NOERROR)
+        return ret;
       break;
      case LDAP_MOD_REPLACE:
-      read_string(a, tree, hf_ldap_message_modify_replace, &t, 0, ASN1_UNI, ASN1_OTS);
+      ret = read_string(a, tree, hf_ldap_message_modify_replace, &ti, 0, ASN1_UNI, ASN1_OTS);
+      if (ret != ASN1_ERR_NOERROR)
+        return ret;
       break;
      case LDAP_MOD_DELETE:
-      read_string(a, tree, hf_ldap_message_modify_delete, &t, 0, ASN1_UNI, ASN1_OTS);
+      ret = read_string(a, tree, hf_ldap_message_modify_delete, &ti, 0, ASN1_UNI, ASN1_OTS);
+      if (ret != ASN1_ERR_NOERROR)
+        return ret;
       break;
     }
-    attr_tree = proto_item_add_subtree(t, ett_ldap_attribute);
+    attr_tree = proto_item_add_subtree(ti, ett_ldap_attribute);
 
-    read_set(a, &set_length);
+    ret = read_set(a, &set_length);
+    if (ret != ASN1_ERR_NOERROR)
+      return ret;
     end_of_set = a->offset + set_length;
-    while (a->offset < end_of_set)
-      read_string(a, attr_tree, hf_ldap_message_value, 0, 0, ASN1_UNI, ASN1_OTS);
+    while (a->offset < end_of_set) {
+      ret = read_string(a, attr_tree, hf_ldap_message_value, 0, 0, ASN1_UNI, ASN1_OTS);
+      if (ret != ASN1_ERR_NOERROR)
+        return ret;
+    }
   }
 
-  return 0;
+  return ASN1_ERR_NOERROR;
 }
 
 static int dissect_ldap_request_abandon(ASN1_SCK *a, proto_tree *tree,
 		int start, guint length)
 {
-  read_integer_value(a, tree, hf_ldap_message_abandon_msgid, NULL, NULL,
-			start, length); 
-  return 0;
+  return read_integer_value(a, tree, hf_ldap_message_abandon_msgid, NULL, NULL,
+			    start, length); 
 }
 
 static void
@@ -902,7 +1026,8 @@ dissect_ldap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
      * segment boundaries.
      */
     message_start = a.offset;
-    if (read_sequence(&a, &messageLength))
+    ret = read_sequence(&a, &messageLength);
+    if (ret != ASN1_ERR_NOERROR)
     {
       if (first_time)
       {
@@ -960,7 +1085,8 @@ dissect_ldap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
     }
 
     message_id_start = a.offset;
-    if (read_integer(&a, 0, -1, 0, &messageId, ASN1_INT))
+    ret = read_integer(&a, 0, -1, 0, &messageId, ASN1_INT);
+    if (ret != ASN1_ERR_NOERROR)
     {
       if (first_time && check_col(pinfo->cinfo, COL_INFO))
         col_set_str(pinfo->cinfo, COL_INFO, "Invalid LDAP packet (No Message ID)");
@@ -994,40 +1120,44 @@ dissect_ldap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
       ti = proto_tree_add_text(ldap_tree, tvb, message_id_start, messageLength, "Message: Id=%u  %s", messageId, typestr);
       msg_tree = proto_item_add_subtree(ti, ett_ldap_message);
       start = a.offset;
-      read_length(&a, msg_tree, hf_ldap_message_length, &opLen);
+      ret = read_length(&a, msg_tree, hf_ldap_message_length, &opLen);
+      if (ret != ASN1_ERR_NOERROR) {
+        proto_tree_add_text(msg_tree, a.tvb, start, 0,
+          "Error parsing length: %s", asn1_err_to_str(ret));
+        return;
+      }
 
       switch (protocolOpTag)
       {
        case LDAP_REQ_BIND:
-        dissect_ldap_request_bind(&a, msg_tree);
+        ret = dissect_ldap_request_bind(&a, msg_tree);
         break;
        case LDAP_REQ_SEARCH:
         ret = dissect_ldap_request_search(&a, msg_tree);
-        /* XXX - do something with "ret" */
         break;
        case LDAP_REQ_ADD:
-        dissect_ldap_request_add(&a, msg_tree);
+        ret = dissect_ldap_request_add(&a, msg_tree);
         break;
        case LDAP_REQ_DELETE:
-        dissect_ldap_request_delete(&a, msg_tree, start, opLen);
+        ret = dissect_ldap_request_delete(&a, msg_tree, start, opLen);
         break;
        case LDAP_REQ_MODRDN:
-        dissect_ldap_request_modifyrdn(&a, msg_tree, opLen);
+        ret = dissect_ldap_request_modifyrdn(&a, msg_tree, opLen);
         break;
        case LDAP_REQ_COMPARE:
-        dissect_ldap_request_compare(&a, msg_tree);
+        ret = dissect_ldap_request_compare(&a, msg_tree);
         break;
        case LDAP_REQ_MODIFY:
-        dissect_ldap_request_modify(&a, msg_tree);
+        ret = dissect_ldap_request_modify(&a, msg_tree);
         break;
        case LDAP_REQ_ABANDON:
-        dissect_ldap_request_abandon(&a, msg_tree, start, opLen);
+        ret = dissect_ldap_request_abandon(&a, msg_tree, start, opLen);
         break;
        case LDAP_RES_BIND:
         dissect_ldap_response_bind(&a, msg_tree);
         break;
        case LDAP_RES_SEARCH_ENTRY:
-        dissect_ldap_response_search_entry(&a, msg_tree);
+        ret = dissect_ldap_response_search_entry(&a, msg_tree);
         break;
        case LDAP_RES_SEARCH_RESULT:
        case LDAP_RES_MODIFY:
@@ -1035,8 +1165,19 @@ dissect_ldap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
        case LDAP_RES_DELETE:
        case LDAP_RES_MODRDN:
        case LDAP_RES_COMPARE:
-        dissect_ldap_result(&a, msg_tree);
+        ret = dissect_ldap_result(&a, msg_tree);
         break;
+       default:
+         proto_tree_add_text(msg_tree, a.tvb, start, 0,
+            "Unknown LDAP operation (%u)", protocolOpTag);
+         ret = ASN1_ERR_NOERROR;
+         break;
+      }
+
+      if (ret != ASN1_ERR_NOERROR) {
+        proto_tree_add_text(msg_tree, a.tvb, start, 0,
+          "Error parsing message: %s", asn1_err_to_str(ret));
+        return;
       }
     }
 
diff --git a/packet-snmp.c b/packet-snmp.c
index f37db104e0..cab3b4c8d2 100644
--- a/packet-snmp.c
+++ b/packet-snmp.c
@@ -8,7 +8,7 @@
  *
  * See RFCs 1905, 1906, 1909, and 1910 for SNMPv2u.
  *
- * $Id: packet-snmp.c,v 1.80 2002/02/19 09:35:45 guy Exp $
+ * $Id: packet-snmp.c,v 1.81 2002/03/01 02:48:10 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -531,34 +531,9 @@ static void
 dissect_snmp_parse_error(tvbuff_t *tvb, int offset, packet_info *pinfo,
 		   proto_tree *tree, const char *field_name, int ret)
 {
-	const gchar *errstr;
+	char *errstr;
 
-	switch (ret) {
-
-	case ASN1_ERR_EOC_MISMATCH:
-		errstr = "EOC mismatch";
-		break;
-
-	case ASN1_ERR_WRONG_TYPE:
-		errstr = "Wrong type for that item";
-		break;
-
-	case ASN1_ERR_LENGTH_NOT_DEFINITE:
-		errstr = "Length was indefinite";
-		break;
-
-	case ASN1_ERR_LENGTH_MISMATCH:
-		errstr = "Length mismatch";
-		break;
-
-	case ASN1_ERR_WRONG_LENGTH_FOR_TYPE:
-		errstr = "Wrong length for that item's type";
-		break;
-
-	default:
-		errstr = "Unknown error";
-		break;
-	}
+	errstr = asn1_err_to_str(ret);
 
 	if (check_col(pinfo->cinfo, COL_INFO)) {
 		col_add_fstr(pinfo->cinfo, COL_INFO,
@@ -567,7 +542,8 @@ dissect_snmp_parse_error(tvbuff_t *tvb, int offset, packet_info *pinfo,
 	if (tree != NULL) {
 		proto_tree_add_text(tree, tvb, offset, 0,
 		    "ERROR: Couldn't parse %s: %s", field_name, errstr);
-		call_dissector(data_handle,tvb_new_subset(tvb, offset,-1,tvb_reported_length_remaining(tvb,offset)), pinfo, tree);
+		call_dissector(data_handle,
+		    tvb_new_subset(tvb, offset, -1, -1), pinfo, tree);
 	}
 }