interface network {
    /// An opaque resource that represents access to (a subset of) the network.
    /// This enables context-based security for networking.
    /// There is no need for this to map 1:1 to a physical network interface.
    resource network;

    /// Error codes.
    ///
    /// In theory, every API can return any error code.
    /// In practice, API's typically only return the errors documented per API
    /// combined with a couple of errors that are always possible:
    /// - `unknown`
    /// - `access-denied`
    /// - `not-supported`
    /// - `out-of-memory`
    /// - `concurrency-conflict`
    ///
    /// See each individual API for what the POSIX equivalents are. They sometimes differ per API.
    enum error-code {
        // ### GENERAL ERRORS ###

        /// Unknown error
        unknown,

        /// Access denied.
        ///
        /// POSIX equivalent: EACCES, EPERM
        access-denied,

        /// The operation is not supported.
        ///
        /// POSIX equivalent: EOPNOTSUPP
        not-supported,

        /// One of the arguments is invalid.
        ///
        /// POSIX equivalent: EINVAL
        invalid-argument,

        /// Not enough memory to complete the operation.
        ///
        /// POSIX equivalent: ENOMEM, ENOBUFS, EAI_MEMORY
        out-of-memory,

        /// The operation timed out before it could finish completely.
        timeout,

        /// This operation is incompatible with another asynchronous operation that is already in progress.
        ///
        /// POSIX equivalent: EALREADY
        concurrency-conflict,

        /// Trying to finish an asynchronous operation that:
        /// - has not been started yet, or:
        /// - was already finished by a previous `finish-*` call.
        ///
        /// Note: this is scheduled to be removed when `future`s are natively supported.
        not-in-progress,

        /// The operation has been aborted because it could not be completed immediately.
        ///
        /// Note: this is scheduled to be removed when `future`s are natively supported.
        would-block,



        // ### TCP & UDP SOCKET ERRORS ###

        /// The operation is not valid in the socket's current state.
        invalid-state,

        /// A new socket resource could not be created because of a system limit.
        new-socket-limit,

        /// A bind operation failed because the provided address is not an address that the `network` can bind to.
        address-not-bindable,

        /// A bind operation failed because the provided address is already in use or because there are no ephemeral ports available.
        address-in-use,

        /// The remote address is not reachable
        remote-unreachable,


        // ### TCP SOCKET ERRORS ###

        /// The connection was forcefully rejected
        connection-refused,

        /// The connection was reset.
        connection-reset,

        /// A connection was aborted.
        connection-aborted,


        // ### UDP SOCKET ERRORS ###
        datagram-too-large,


        // ### NAME LOOKUP ERRORS ###

        /// Name does not exist or has no suitable associated IP addresses.
        name-unresolvable,

        /// A temporary failure in name resolution occurred.
        temporary-resolver-failure,

        /// A permanent failure in name resolution occurred.
        permanent-resolver-failure,
    }

    enum ip-address-family {
        /// Similar to `AF_INET` in POSIX.
        ipv4,

        /// Similar to `AF_INET6` in POSIX.
        ipv6,
    }

    type ipv4-address = tuple<u8, u8, u8, u8>;
    type ipv6-address = tuple<u16, u16, u16, u16, u16, u16, u16, u16>;

    variant ip-address {
        ipv4(ipv4-address),
        ipv6(ipv6-address),
    }

    record ipv4-socket-address {
        port: u16, // sin_port
        address: ipv4-address, // sin_addr
    }

    record ipv6-socket-address {
        port: u16, // sin6_port
        flow-info: u32, // sin6_flowinfo
        address: ipv6-address, // sin6_addr
        scope-id: u32, // sin6_scope_id
    }

    variant ip-socket-address {
        ipv4(ipv4-socket-address),
        ipv6(ipv6-socket-address),
    }

}