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dns-toy/lib/utils.ml

54 lines
1.5 KiB
OCaml

let get_bytecode ?(json = false) data =
let backslash = '\\' in
let result =
String.concat
""
(List.map
(fun byte ->
let code = Char.code byte in
if code >= 65 && code <= 122
then String.make 1 byte
else Printf.sprintf "%cx%02X" backslash code)
(List.of_seq (Bytes.to_seq data)))
in
if json
then
String.concat
""
(List.map
(fun c -> if c = backslash then String.make 2 c else String.make 1 c)
(List.of_seq (String.to_seq result)))
else result
;;
let get_obj_size obj = Obj.size (Obj.repr obj)
let new_buffer size list =
let buffer = Bytes.create size in
let verification =
List.fold_left
(fun acc field ->
Bytes.set_uint16_be buffer acc field;
acc + 2)
0
list
in
if verification != size then failwith "Issue converting header to bytes";
buffer
;;
let unpack_short_be data offset =
let msb = int_of_char (Bytes.get data offset) in
let lsb = int_of_char (Bytes.get data (offset + 1)) in
(msb lsl 8) + lsb
;;
let unpack_int_be data offset =
let byte1 = int_of_char (Bytes.get data offset) in
let byte2 = int_of_char (Bytes.get data (offset + 1)) in
let byte3 = int_of_char (Bytes.get data (offset + 2)) in
let byte4 = int_of_char (Bytes.get data (offset + 3)) in
(byte1 lsl 24) lor (byte2 lsl 16) lor (byte3 lsl 8) lor byte4
;;
let bytes_forward data offset = Bytes.sub data offset (Bytes.length data - offset)