Dear sir :
Please excuse me for I'm taking the liberty of writing to you. I' m
a chinese. I have a wireshark dissector question which I would like to ask you.
To make my example as plain
and interesting as possible, so I use the example of the official website
:https://www.wireshark.org/docs/wsdg_html_chunked/ChDissectAdd.html .
Example 9.12. Enhancing the display.
static void
dissect_foo(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
guint8 packet_type = tvb_get_guint8(tvb, 0);
col_set_str(pinfo->cinfo, COL_PROTOCOL, "FOO");
/* Clear out stuff in the info column */
col_clear(pinfo->cinfo,COL_INFO);
col_add_fstr(pinfo->cinfo, COL_INFO, "Type %s",
val_to_str(packet_type, packettypenames, "Unknown (0x%02x)"));
if (tree) { /* we are being asked for details */
proto_item *ti = NULL;
proto_tree *foo_tree = NULL;
gint offset = 0;
ti = proto_tree_add_item(tree, proto_foo, tvb, 0, -1, ENC_NA);
proto_item_append_text(ti, ", Type %s",
val_to_str(packet_type, packettypenames, "Unknown (0x%02x)"));
foo_tree = proto_item_add_subtree(ti, ett_foo);
proto_tree_add_item(foo_tree, hf_foo_pdu_type, tvb, offset, 1,
ENC_BIG_ENDIAN);
offset += 1;
}
}
1.Suppose there are three packets, then dissect_foo is called many times?
2. If I click one row in wireshark 's user interface， then dissect_foo will be
called many times?
3. How can I debug the code slice:
if (tree) { /* we are being asked for details */
proto_item *ti = NULL;
proto_tree *foo_tree = NULL;
gint offset = 0;
ti = proto_tree_add_item(tree, proto_foo, tvb, 0, -1, ENC_NA);
proto_item_append_text(ti, ", Type %s",
val_to_str(packet_type, packettypenames, "Unknown (0x%02x)"));
foo_tree = proto_item_add_subtree(ti, ett_foo);
proto_tree_add_item(foo_tree, hf_foo_pdu_type, tvb, offset, 1,
ENC_BIG_ENDIAN);
offset += 1;
}
Thanks ! Looking forward to your reply.___________________________________________________________________________
Sent via: Wireshark-dev mailing list <[email protected]>
Archives: https://www.wireshark.org/lists/wireshark-dev
Unsubscribe: https://wireshark.org/mailman/options/wireshark-dev
mailto:[email protected]?subject=unsubscribe
