Wireshark-dev: Re: [Wireshark-dev] invalid output in pidl generated dcercp-mapi & dercp-nspi di

From: Alexis La Goutte <alexis.lagoutte@xxxxxxxxx>
Date: Fri, 12 Feb 2016 10:45:51 +0100
Hi Aurélien,

Yes, There is some issue with mapi dissector actually
we have no the same result when regenerate mapi dissector...

And yes, the code don't build...


On Thu, Feb 11, 2016 at 4:26 PM, Aurélien Aptel <aaptel@xxxxxxxx> wrote:

I'm in the process of syncing tools/pidl with samba (almost done, more
on this later).

Using master (0cd0844) bundled pidl, I wanted to make sure none of the
generated dissectors were edited by hand so I've run the following
(from epan/dissectors/pidl/README) to regenerate them:

    cd epan/dissectors/pidl
    for file in *.idl */*.idl; do
        echo "Generating dissector for $file"
        ../../../tools/pidl/pidl --includedir . --ws-parser -- $file;
    cp packet-dcerpc*.* ..

Most generated files are almost identical (slightly altered comments and
whitespace because pidl wasn't run again) except for
packet-dcerpc-mapi.[ch] and packet-dcerpc-nsapi.[ch] who differs
greatly. These new generated files don't compile because they are
malformed. Sample output:

static int
mapi_dissect_element_SPropValue_value(tvbuff_t *tvb _U_, int offset _U_, packet_info *pinfo _U_, proto_tree *tree _U_, dcerpc_info* di _U_, guint8 *drep _U_, guint32 *)
        offset = mapi_dissect_SPropValue_CTR(tvb, offset, pinfo, tree, di, drep, hf_mapi_property_types, *);

        return offset;

Notice the lone * at the last param of the call.
I've tried to debug it (but I don't know much about pidl)

in tools/pidl/lib/Parse/Pidl/Wireshark/NDR.pm:446 (sub Element)

        if (defined $isoruseswitch) {
                my $type = $isoruseswitch->[0];
                my $name = $isoruseswitch->[1];

                my $switch_dt =  getType($type);
                my $switch_raw_type = SwitchType($e, $type, "uint32");
                if (not defined($switch_raw_type)) {
                        die("Unknown type[$type]\n");
                my $switch_type = "g${switch_raw_type}";

                $moreparam = ", $switch_type *".$name;

                if (($e->{PROPERTIES}->{switch_is} eq "") && ($switchvars{$name}) &&
                        #not a "native" type
                        (!($type =~ /^uint(8|16|1632|32|3264|64)/))) {
                        $param = $name;
                } elsif ( $switch_dt->{DATA}->{TYPE} eq "ENUM") {
                        $param = $name;
                } else {
                        $param = "*".$name;
                        # ^^^^^^^^^^^^^^^^^
                        # here we prefix the param
                        # with a star but $name is empty

Later in the same sub we call ElementLevel with $param eq "*"


Finally, in the sub ElementLevel we generate the wrong call:

        } elsif (defined($self->{conformance}->{types}->{$l->{DATA_TYPE}})) {
                $call= $self->{conformance}->{types}->{$l->{DATA_TYPE}}->{DISSECTOR_NAME};
                $self->{conformance}->{types}->{$l->{DATA_TYPE}}->{USED} = 1;
        } else {

Here $call is set to

"offset = mapi_dissect_SPropValue_CTR(tvb, offset, pinfo, tree, di, drep, @HF@, @PARAM@);"

And @PARAM@ is replaced with "*".

Aurélien Aptel / SUSE Labs Samba Team
GPG: 1839 CB5F 9F5B FB9B AA97  8C99 03C8 A49B 521B D5D3
SUSE Linux GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG

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