Wireshark-dev: Re: [Wireshark-dev] Current Lua test failures on the buildbot
From: João Valverde <[email protected]>
Date: Sun, 7 Aug 2016 13:39:12 +0100

On 08/07/2016 04:02 AM, João Valverde wrote:

On 08/07/2016 03:47 AM, Guy Harris wrote:
Tested on an up-to-date Ubuntu 15.10 system; the test fails.  The
TShark build information is:

    TShark (Wireshark) 2.3.0 (v2.3.0rc0-230-ge32890a from master)

    Copyright 1998-2016 Gerald Combs <[email protected]> and
contributors.
    License GPLv2+: GNU GPL version 2 or later
<http://www.gnu.org/licenses/old-licenses/gpl-2.0.html>
    This is free software; see the source for copying conditions.
There is NO
    warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE.

    Compiled (64-bit) with libpcap, with POSIX capabilities (Linux),
with libnl 3,
    with GLib 2.46.2, with zlib 1.2.8, with SMI 0.4.8, with c-ares
1.10.0, with Lua
    5.2, with GnuTLS 3.3.15, with Gcrypt 1.6.3, with MIT Kerberos,
with GeoIP.

    Running on Linux 4.2.0-42-generic, with locale en_US.UTF-8, with
libpcap version
    1.7.4, with GnuTLS 3.3.15, with Gcrypt 1.6.3, with zlib 1.2.8.
    Intel(R) Core(TM) i7-4980HQ CPU @ 2.80GHz (with SSE4.2)

    Built using gcc 5.2.1 20151010.

It also fails on an Ubuntu 14.10 system; the TShark build information is:

    TShark (Wireshark) 2.3.0 (v2.3.0rc0-230-ge32890a from master)

    Copyright 1998-2016 Gerald Combs <[email protected]> and
contributors.
    License GPLv2+: GNU GPL version 2 or later
<http://www.gnu.org/licenses/old-licenses/gpl-2.0.html>
    This is free software; see the source for copying conditions.
There is NO
    warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE.

    Compiled (64-bit) with libpcap, without POSIX capabilities, with
libnl 3, with
    GLib 2.42.1, with zlib 1.2.8, without SMI, without c-ares, with
Lua 5.2, without
    GnuTLS, without Gcrypt, without Kerberos, without GeoIP.

    Running on Linux 3.16.0-44-generic, with locale en_US.UTF-8, with
libpcap
    version 1.6.2, with zlib 1.2.8.
    Intel(R) Core(TM) i7-4980HQ CPU @ 2.80GHz (with SSE4.2)

    Built using gcc 4.9.1.

For what it's worth, the tests in question seem to be working on a
"string" that's a byte array with byte values from 0 to 255; that's
not a valid UTF-8 string, so if the processing that's failing is
assuming a UTF-8 string, its behavior isn't guaranteed not to change
from, say, GLib release to GLib release.
To be honest having our own GLib lrexlib bindings is a horrible idea
(even more so for a possibly useful feature).

Brilliant piece of code but it should be merged upstream, not maintained
in the Wireshark tree with a bus factor of 1.
Seriously, what's the point of this craziness when this works fine:

$ luarocks install lrexlib-pcre-2.8.0-1.src.rock
$ cat wslua-pcre.lua
rex = require("rex_pcre")
print(rex.version())
$ tshark -r test/captures/empty.pcap -X lua_script:wslua-pcre.lua
8.39 2016-06-14

Digging around a bit I see that Hadriel didn't want to complicate the build process with a libpcre dependency (!) so he ended up writing a whole new lrexlib binding (!!!).
I propose we write our own regular expression engine instead so we don't 
have to worry about pesky complications such as having a build 
dependency on GRegex. :-D