From Neil Piercy:

Fix  misleading PER Bit string display.
https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=4789
(I Added bits display)

git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@32948 f5534014-38df-0310-8fa8-9805f1628bb7

diff --git a/epan/dissectors/packet-per.c b/epan/dissectors/packet-per.c
index 2353ba73f950334d85364423570aae2b59959f0b..617bc871c223002ed453e41e182054c2d275ccf9 100644 (file)
--- a/epan/dissectors/packet-per.c
+++ b/epan/dissectors/packet-per.c
@@ -2018,6 +2018,42 @@ DEBUG_ENTRY("dissect_per_sequence");
    max_len or min_len == NO_BOUND means there is no lower/upper constraint
 
 */
+
+static tvbuff_t *dissect_per_bit_string_display(tvbuff_t *tvb, guint32 offset, asn1_ctx_t *actx, proto_tree *tree, int hf_index, header_field_info *hfi, guint32 length)
+{
+       tvbuff_t *out_tvb = NULL;
+       guint32  value, pad_length=0;
+       
+       out_tvb = new_octet_aligned_subset_bits(tvb, offset, actx, length);
+       
+       if (hfi) {
+               actx->created_item = proto_tree_add_item(tree, hf_index, out_tvb, 0, -1, FALSE);
+               proto_item_append_text(actx->created_item, " [bit length %u", length);
+               if (length%8) {
+                       pad_length = 8-(length%8);
+                       proto_item_append_text(actx->created_item, ", %u LSB pad bits", pad_length);
+               }
+               
+               if (length<=32) {
+                       if (length<=8)
+                               value = tvb_get_guint8(out_tvb, 0);
+                       else if (length<=16)
+                               value = tvb_get_ntohs(out_tvb, 0);
+                       else if (length<=24)
+                               value = tvb_get_ntoh24(out_tvb, 0);
+                       else
+                               value = tvb_get_ntohl(out_tvb, 0);
+                       
+                       value >>= pad_length;
+                       
+                       proto_item_append_text(actx->created_item, ", %s decimal value %u", 
+                               decode_bits_in_field(0, length, value), value);
+               }
+               proto_item_append_text(actx->created_item, "]");
+       }
+
+       return out_tvb;
+}
 guint32
 dissect_per_bit_string(tvbuff_t *tvb, guint32 offset, asn1_ctx_t *actx, proto_tree *tree, int hf_index, int min_len, int max_len, gboolean has_extension, tvbuff_t **value_tvb)
 {
@@ -2052,12 +2088,7 @@ DEBUG_ENTRY("dissect_per_bit_string");
                                if (actx->aligned){
                                        BYTE_ALIGN_OFFSET(offset);
                                }
-                               out_tvb = new_octet_aligned_subset_bits(tvb, offset, actx, length);
-
-                               if (hfi) {
-                                       actx->created_item = proto_tree_add_item(tree, hf_index, out_tvb, 0, -1, FALSE);
-                                       proto_item_append_text(actx->created_item, " [bit length %u]", length);
-                               }
+                               out_tvb = dissect_per_bit_string_display(tvb, offset, actx, tree, hf_index, hfi, length);
                        }
                        val_start = offset>>3;
                        val_length = (length+7)/8;
@@ -2072,11 +2103,7 @@ DEBUG_ENTRY("dissect_per_bit_string");
 
        /* 15.9 if length is fixed and less than or equal to sixteen bits*/
        if ((min_len==max_len) && (max_len<=16)) {
-               out_tvb = new_octet_aligned_subset_bits(tvb, offset, actx, min_len);
-               if (hfi) {
-                       actx->created_item = proto_tree_add_item(tree, hf_index, out_tvb, 0, -1, FALSE);
-                       proto_item_append_text(actx->created_item, " [bit length %u]", max_len);
-               }
+               out_tvb = dissect_per_bit_string_display(tvb, offset, actx, tree, hf_index, hfi, min_len);
                offset+=min_len;
                if (value_tvb)
                        *value_tvb = out_tvb;
@@ -2093,11 +2120,7 @@ DEBUG_ENTRY("dissect_per_bit_string");
                        /* TODO the displayed value will be wrong for the unaligned variant */
                        BYTE_ALIGN_OFFSET(offset);
                }
-               out_tvb = new_octet_aligned_subset_bits(tvb, offset, actx, min_len);
-               if (hfi) {
-                       actx->created_item = proto_tree_add_item(tree, hf_index, out_tvb, 0, -1, FALSE);
-                       proto_item_append_text(actx->created_item, " [bit length %u]", max_len);
-               }
+               out_tvb = dissect_per_bit_string_display(tvb, offset, actx, tree, hf_index, hfi, min_len);
                offset+=min_len;
                if (value_tvb)
                        *value_tvb = out_tvb;
@@ -2118,12 +2141,7 @@ DEBUG_ENTRY("dissect_per_bit_string");
                if (actx->aligned){
                        BYTE_ALIGN_OFFSET(offset);
                }
-               out_tvb = new_octet_aligned_subset_bits(tvb, offset, actx, length);
-
-               if (hfi) {
-                       actx->created_item = proto_tree_add_item(tree, hf_index, out_tvb, 0, -1, FALSE);
-                       proto_item_append_text(actx->created_item, " [bit length %u]", length);
-               }
+               out_tvb = dissect_per_bit_string_display(tvb, offset, actx, tree, hf_index, hfi, length);
        }
        val_start = offset>>3;
        val_length = (length+7)/8;