From 5b3c9427a8d3b3ca9f24bd3e95859dee66f328cc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?F=C3=A9lix=20Baylac=20Jacqu=C3=A9?=
 <felix@alternativebit.fr>
Date: Fri, 15 Sep 2023 10:25:25 +0200
Subject: [PATCH] AddToStore: implement payload/response

The AddToStore operation is performed in 3 packets:

1. AddToStore request metadata.
2. AddToStore payload.
3. Response from the daemon.

This means we need to keep some sort of processing state for the
operation.
---
 nix-packet.lua | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/nix-packet.lua b/nix-packet.lua
index 7560775..784795e 100644
--- a/nix-packet.lua
+++ b/nix-packet.lua
@@ -19,6 +19,10 @@ local op_addtostore_camstr = ProtoField.string("nix.addtostore.camstr", "Add to
 local op_addtostore_nb_references = ProtoField.uint64("nix.addtostore.nbreferences", "Number of References")
 local op_addtostore_reference = ProtoField.string("nix.addtostore.reference", "Reference")
 local op_addtostore_repairflag = ProtoField.bool("nix.addtostore.repairflag", "Repair Flag")
+local op_addtostore_payload = ProtoField.bytes("nix.addtostore.payload", "Request Payload")
+local op_addtostore_response = ProtoField.bytes("nix.addtostore.response", "Response")
+
+op_addtostore_step = 0
 
 nix_proto.fields = {
    dst_field,
@@ -38,6 +42,8 @@ nix_proto.fields = {
    op_addtostore_nb_references,
    op_addtostore_reference,
    op_addtostore_repairflag,
+   op_addtostore_payload,
+   op_addtostore_response,
 }
 
 local op_table = {
@@ -165,11 +171,25 @@ function parse_add_to_store(tvb, pinfo, tree, offset)
    end
 
    local repairflag = subtree:add(op_addtostore_repairflag, tvb(offset, 1))
+
    offset = offset + 8
+   op_addtostore_step = 2
 
    return offset
 end
 
+function process_op_addtostore_step(tvb, pinfo, tree, offset)
+   if op_addtostore_step == 2 then
+      local subtree = tree:add(op_addtostore, tvb(offset, tvb:len() - offset))
+      subtree:add(op_addtostore_payload, tvb(offset, tvb:len() - offset))
+   elseif op_addtostore_step == 1 then
+      local subtree = tree:add(op_addtostore, tvb(offset, tvb:len() - offset))
+      subtree:add(op_addtostore_response, tvb(offset, tvb:len() - offset))
+   end
+
+   op_addtostore_step = op_addtostore_step - 1
+end
+
 function parse_op(tvb, pinfo, tree, offset, op)
    tree:add(op_name_field, tvb(offset, 8), op_table[op])
    offset = offset + 8
@@ -191,7 +211,10 @@ function nix_proto.dissector(tvb, pinfo, tree)
    offset = offset + 8
 
    local first_word = tvb(offset, 4):le_uint()
-   if first_word == 0x6e697863 then
+
+   if op_addtostore_step > 0 then
+      process_op_addtostore_step(tvb, pinfo, subtree, offset)
+   elseif first_word == 0x6e697863 then
       offset = parse_client_hello(tvb, pinfo, subtree, offset)
    elseif first_word == 0x6478696f then
       offset = parse_daemon_hello(tvb, pinfo, subtree, offset)