transform: luaxform transform script

[jlucovsky]

Continuation of #12098

Add the luaxform transform that uses a Lua script to receive and transform a sticky buffer.

Lua transforms receive arguments

• (always): length of input buffer and input buffer
• (always): number of additional arguments (may be 0)
• (when present): argument array (bounded by argument count)

Arguments are passed to the Lua script as they appear in the rule:

 luaxform:./lua/lua-transform.lua, bytes 4, offset 13, hash sha256;

When the transform is invoked, 3 additional arguments are passed (arg count will be 3)

• bytes 4
• offset 13
• hash sha256

The Lua script is responsible for parsing and using the arguments and returning a tuple: output-buffer, output-buffer-byte-count

I used this Lua script:

function init (args)
  -- Optional, no return value
end

function transform(input_len, input, argc, args)
    SCLogNotice("Input length: " .. input_len .. " arg-count: " .. argc)
    for i = 1, argc do
        print("Argument " .. i .. ":", args[i])
    end
    return string.upper(input), input_len
end

return 0

Example rule using the Lua script:

alert http any any -> any any (msg:"Lua Xform example"; flow:established;  file.data; luaxform:./lua/lua-transform.lua; content: "abc"; sid: 1;)

Link to ticket: https://redmine.openinfosecfoundation.org/issues/2290

Describe changes:

• Luaxform transform changes

Updates

• Address formatting issue

Provide values to any of the below to override the defaults.

• To use an LibHTP, Suricata-Verify or Suricata-Update pull request,
  link to the pull request in the respective _BRANCH variable.
• Leave unused overrides blank or remove.

SV_REPO=
SV_BRANCH=OISF/suricata-verify#2090
SU_REPO=
SU_BRANCH=
LIBHTP_REPO=
LIBHTP_BRANCH=

[jlucovsky]

Continued in #12131

[codecov]

Codecov Report

Attention: Patch coverage is 86.51685% with 60 lines in your changes missing coverage. Please review.

Project coverage is 83.10%. Comparing base (5d766df) to head (01937b8).

Additional details and impacted files

@@             Coverage Diff             @@
##           master   #12130       +/-   ##
===========================================
+ Coverage   62.68%   83.10%   +20.42%     
===========================================
  Files         840      912       +72     
  Lines      153669   258096   +104427     
===========================================
+ Hits        96323   214496   +118173     
+ Misses      57346    43600    -13746     

Flag	Coverage Δ
fuzzcorpus	60.86% <46.65%> (?)
livemode	19.44% <13.39%> (?)
pcap	44.34% <30.48%> (?)
suricata-verify	62.74% <83.83%> (+0.06%)	⬆️
unittests	59.24% <26.74%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

---- 🚨 Try these New Features:

• Flaky Tests Detection - Detect and resolve failed and flaky tests