transform: luaxform transform script

[jlucovsky]

Continuation of #11733

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)
    local needs = {}
    return needs
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

• Rebase

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#2044
SU_REPO=
SU_BRANCH=
LIBHTP_REPO=
LIBHTP_BRANCH=

[catenacyber]

Could this file be in rust ?

[jlucovsky]

There's no reason why it couldn't; I chose C since the majority of transforms are expressed in C.

[catenacyber]

opening a new PR with a transform in rust soon ;-)

[catenacyber]

#11861 ;-)

[codecov]

Codecov Report

Attention: Patch coverage is 29.55326% with 205 lines in your changes missing coverage. Please review.

Project coverage is 79.00%. Comparing base (7ab8334) to head (959e813).
Report is 17 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #11817      +/-   ##
==========================================
- Coverage   82.58%   79.00%   -3.58%     
==========================================
  Files         914      917       +3     
  Lines      249500   249562      +62     
==========================================
- Hits       206045   197169    -8876     
- Misses      43455    52393    +8938     

Flag	Coverage Δ
fuzzcorpus	60.51% <28.86%> (+0.07%)	⬆️
livemode	18.72% <15.46%> (+<0.01%)	⬆️
pcap	44.04% <18.55%> (-0.03%)	⬇️
suricata-verify	?
unittests	58.92% <21.30%> (-0.04%)	⬇️

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

[suricata-qa]

WARNING:

field	baseline	test	%
	SURI_TLPR1_stats_chk
.uptime	649	625	96.3%

Pipeline 22858

[jlucovsky]

Continued in #11860