Internet-Style Packet Format (ISPF) for Serde

This crate provides machinery for serializing and deserializing Internet-style packets with Serde.

By Example

Consider the following Internet-style packet

 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                              size                             |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|     type      |              tag              |     msize     :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
:                                               |  version.size :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
:               |                   version                     :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
:                               ...                             :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

with Serde/ISPF this can be represented as

#[derive(Debug, Serialize, Deserialize, PartialEq)]
struct Version {
    size: u32,
    typ: u8,
    tag: u16,
    msize: u32,
    #[serde(with = "ispf::str_lv16")]
    version: String,
}

The annotation on version in this data structure indicates that version should be serialized as a length-value pair with a 16-bit unsigned integer as the length.

A basic round trip to and from wire format is performed as the following (full example).

let v = Version{
    size: 47,
    typ: 9,
    tag: 15,
    msize: 99,
    version: "muffin".into(),
};

let out = to_bytes_le(&v)?;
println!("{:?}", out);

let full_circle: Version = from_bytes_le(out.as_slice())?;
println!("{:#?}", full_circle);
assert_eq!(v, full_circle);

So the basic thing that ISPF does is create packed wire representations for Rust data types and provides a configurable means by which to represent types that are not statically sized, such as the ispf::str_lv64 serializer annotation above.

Available Formatters

Strings

• str_lv8
• str_lv16
• str_lv32
• str_lv64

Length value represents the number of total bytes in the string.

Vectors by count

• vec_lv8
• vec_lv16
• vec_lv32
• vec_lv64

Length value represents number of elements in the vector.

Vectors by bytes

• vec_lv8b
• vec_lv16b
• vec_lv32b
• vec_lv64b

Length value represents number of total bytes in the vector (the sum of the size of the elements).

Building

cargo build
cargo test