From 7a5fd1e47275591f8692d5fcabc5a5694f31a781 Mon Sep 17 00:00:00 2001
From: Mylloon <kennel.anri@tutanota.com>
Date: Wed, 14 Jun 2023 16:54:55 +0200
Subject: [PATCH] starting dns record parsing

---
 bin/main.ml     |  6 ++++--
 lib/debug.ml    | 10 ++++++++++
 lib/response.ml | 10 ++++++++--
 lib/types.ml    |  8 ++++++++
 4 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/bin/main.ml b/bin/main.ml
index 613cf14..c7ba09e 100644
--- a/bin/main.ml
+++ b/bin/main.ml
@@ -4,7 +4,9 @@ let () =
   let response = Network.send_request "8.8.8.8" "www.example.com" in
   print_endline (Utils.get_bytecode response);
   let response', dns_header = Response.parse_header response in
-  let dns_question = Response.parse_question response' in
+  let response'', dns_question = Response.parse_question response' in
+  let dns_record = Response.parse_record response'' in
   Debug.print_dns_header dns_header;
-  Debug.print_dns_question dns_question
+  Debug.print_dns_question dns_question;
+  Debug.print_dns_record dns_record
 ;;
diff --git a/lib/debug.ml b/lib/debug.ml
index f79f738..53f4f05 100644
--- a/lib/debug.ml
+++ b/lib/debug.ml
@@ -17,3 +17,13 @@ let print_dns_question (question : Types.dns_question) =
     question.type_
     question.class_
 ;;
+
+let print_dns_record (record : Types.dns_record) =
+  Printf.printf
+    "{ name = '%s'; type_ = %d; class_ = %d; ttl = %d; data = '%s' }\n"
+    (Bytes.to_string record.name)
+    record.type_
+    record.class_
+    record.ttl
+    (Bytes.to_string record.data)
+;;
diff --git a/lib/response.ml b/lib/response.ml
index 56402d4..04b7890 100644
--- a/lib/response.ml
+++ b/lib/response.ml
@@ -13,8 +13,9 @@ let parse_header reader =
 let rec parse_question reader =
   let reader', name_b = decode_name_simple reader in
   let name = String.to_bytes name_b in
-  match List.init 2 (fun offset -> unpack_short_be reader' (offset * 2)) with
-  | [ type_; class_ ] -> { name; type_; class_ }
+  let max_size = 2 in
+  match List.init max_size (fun offset -> unpack_short_be reader' (offset * 2)) with
+  | [ type_; class_ ] -> bytes_forward reader' (max_size * 2), { name; type_; class_ }
   | _ -> failwith "Invalid number of fields"
 
 and decode_name_simple reader =
@@ -30,3 +31,8 @@ and decode_name_simple reader =
   let offset, parts = read_parts [] 0 in
   bytes_forward reader offset, String.concat "." parts
 ;;
+
+let parse_record _reader =
+  let name, type_, class_, ttl, data = Bytes.empty, 0, 0, 0, Bytes.empty in
+  { name; type_; class_; ttl; data }
+;;
diff --git a/lib/types.ml b/lib/types.ml
index ccfc017..de0d1d0 100644
--- a/lib/types.ml
+++ b/lib/types.ml
@@ -12,3 +12,11 @@ type dns_question =
   ; type_ : int
   ; class_ : int
   }
+
+type dns_record =
+  { name : bytes
+  ; type_ : int
+  ; class_ : int
+  ; ttl : int
+  ; data : bytes
+  }