librustls: replace castable macros

They're helpful, but require us to use cbindgen's parse.expand feature
which in turn requires nightly, and is broken with nightly since ~April.

Author: cpu

librustls/src/acceptor.rs

@@ -4,51 +4,61 @@ use rustls::server::{Accepted, AcceptedAlert, Acceptor};
 use crate::connection::rustls_connection;
 use crate::error::{map_error, rustls_io_result, rustls_result};
 use crate::ffi::{
-    box_castable, free_box, set_boxed_mut_ptr, to_box, to_boxed_mut_ptr, try_callback,
+    Castable, OwnershipBox, free_box, set_boxed_mut_ptr, to_box, to_boxed_mut_ptr, try_callback,
     try_clone_arc, try_mut_from_ptr, try_mut_from_ptr_ptr, try_ref_from_ptr, try_take,
 };
 use crate::io::{CallbackReader, CallbackWriter, rustls_read_callback, rustls_write_callback};
 use crate::panic::ffi_panic_boundary;
 use crate::rslice::{rustls_slice_bytes, rustls_str};
 use crate::server::rustls_server_config;
 
-box_castable! {
-    /// A buffer and parser for ClientHello bytes.
-    ///
-    /// This allows reading ClientHello before choosing a rustls_server_config.
-    ///
-    /// It's useful when the server config will be based on parameters in the
-    /// ClientHello: server name indication (SNI), ALPN protocols, signature
-    /// schemes, and cipher suites.
-    ///
-    /// In particular, if a server wants to do some potentially expensive work
-    /// to load a certificate for a given hostname, rustls_acceptor allows doing
-    /// that asynchronously, as opposed to rustls_server_config_builder_set_hello_callback(),
-    /// which doesn't work well for asynchronous I/O.
-    ///
-    /// The general flow is:
-    ///  - rustls_acceptor_new()
-    ///  - Loop:
-    ///    - Read bytes from the network it with rustls_acceptor_read_tls().
-    ///    - If successful, parse those bytes with rustls_acceptor_accept().
-    ///    - If that returns RUSTLS_RESULT_ACCEPTOR_NOT_READY, continue.
-    ///    - Otherwise, break.
-    ///  - If rustls_acceptor_accept() returned RUSTLS_RESULT_OK:
-    ///    - Examine the resulting rustls_accepted.
-    ///    - Create or select a rustls_server_config.
-    ///    - Call rustls_accepted_into_connection().
-    ///  - Otherwise, there was a problem with the ClientHello data and the
-    ///    connection should be rejected.
-    pub struct rustls_acceptor(Acceptor);
+/// A buffer and parser for ClientHello bytes.
+///
+/// This allows reading ClientHello before choosing a rustls_server_config.
+///
+/// It's useful when the server config will be based on parameters in the
+/// ClientHello: server name indication (SNI), ALPN protocols, signature
+/// schemes, and cipher suites.
+///
+/// In particular, if a server wants to do some potentially expensive work
+/// to load a certificate for a given hostname, rustls_acceptor allows doing
+/// that asynchronously, as opposed to rustls_server_config_builder_set_hello_callback(),
+/// which doesn't work well for asynchronous I/O.
+///
+/// The general flow is:
+///  - rustls_acceptor_new()
+///  - Loop:
+///    - Read bytes from the network it with rustls_acceptor_read_tls().
+///    - If successful, parse those bytes with rustls_acceptor_accept().
+///    - If that returns RUSTLS_RESULT_ACCEPTOR_NOT_READY, continue.
+///    - Otherwise, break.
+///  - If rustls_acceptor_accept() returned RUSTLS_RESULT_OK:
+///    - Examine the resulting rustls_accepted.
+///    - Create or select a rustls_server_config.
+///    - Call rustls_accepted_into_connection().
+///  - Otherwise, there was a problem with the ClientHello data and the
+///    connection should be rejected.
+pub struct rustls_acceptor {
+    _private: [u8; 0],
 }
 
-box_castable! {
-    /// A parsed ClientHello produced by a rustls_acceptor.
-    ///
-    /// It is used to check server name indication (SNI), ALPN protocols,
-    /// signature schemes, and cipher suites. It can be combined with a
-    /// `rustls_server_config` to build a `rustls_connection`.
-    pub struct rustls_accepted(Option<Accepted>);
+impl Castable for rustls_acceptor {
+    type Ownership = OwnershipBox;
+    type RustType = Acceptor;
+}
+
+/// A parsed ClientHello produced by a rustls_acceptor.
+///
+/// It is used to check server name indication (SNI), ALPN protocols,
+/// signature schemes, and cipher suites. It can be combined with a
+/// `rustls_server_config` to build a `rustls_connection`.
+pub struct rustls_accepted {
+    _private: [u8; 0],
+}
+
+impl Castable for rustls_accepted {
+    type Ownership = OwnershipBox;
+    type RustType = Option<Accepted>;
 }
 
 impl rustls_acceptor {
@@ -446,9 +456,14 @@ impl rustls_accepted {
     }
 }
 
-box_castable! {
-    /// Represents a TLS alert resulting from accepting a client.
-    pub struct rustls_accepted_alert(AcceptedAlert);
+/// Represents a TLS alert resulting from accepting a client.
+pub struct rustls_accepted_alert {
+    _private: [u8; 0],
+}
+
+impl Castable for rustls_accepted_alert {
+    type Ownership = OwnershipBox;
+    type RustType = AcceptedAlert;
 }
 
 impl rustls_accepted_alert {

librustls/src/certificate.rs

@@ -12,18 +12,24 @@ use rustls::sign::CertifiedKey;
 use crate::crypto_provider::{self, rustls_signing_key};
 use crate::error::{map_error, rustls_result};
 use crate::ffi::{
-    arc_castable, box_castable, free_arc, free_box, ref_castable, set_arc_mut_ptr,
+    Castable, OwnershipArc, OwnershipBox, OwnershipRef, free_arc, free_box, set_arc_mut_ptr,
     to_arc_const_ptr, to_boxed_mut_ptr, try_box_from_ptr, try_mut_from_ptr, try_ref_from_ptr,
     try_ref_from_ptr_ptr, try_slice, try_take,
 };
 use crate::panic::ffi_panic_boundary;
 use crate::rslice::rustls_slice_bytes;
 
-ref_castable! {
-    /// An X.509 certificate, as used in rustls.
-    /// Corresponds to `CertificateDer` in the Rust pki-types API.
-    /// <https://docs.rs/rustls-pki-types/latest/rustls_pki_types/struct.CertificateDer.html>
-    pub struct rustls_certificate(CertificateDer<'a>);
+/// An X.509 certificate, as used in rustls.
+/// Corresponds to `CertificateDer` in the Rust pki-types API.
+/// <https://docs.rs/rustls-pki-types/latest/rustls_pki_types/struct.CertificateDer.html>
+pub struct rustls_certificate<'a> {
+    _private: [u8; 0],
+    _marker: PhantomData<&'a ()>,
+}
+
+impl<'a> Castable for rustls_certificate<'a> {
+    type Ownership = OwnershipRef;
+    type RustType = CertificateDer<'a>;
 }
 
 /// Get the DER data of the certificate itself.
@@ -48,13 +54,18 @@ pub extern "C" fn rustls_certificate_get_der(
     }
 }
 
-arc_castable! {
-    /// The complete chain of certificates to send during a TLS handshake,
-    /// plus a private key that matches the end-entity (leaf) certificate.
-    ///
-    /// Corresponds to `CertifiedKey` in the Rust API.
-    /// <https://docs.rs/rustls/latest/rustls/sign/struct.CertifiedKey.html>
-    pub struct rustls_certified_key(CertifiedKey);
+/// The complete chain of certificates to send during a TLS handshake,
+/// plus a private key that matches the end-entity (leaf) certificate.
+///
+/// Corresponds to `CertifiedKey` in the Rust API.
+/// <https://docs.rs/rustls/latest/rustls/sign/struct.CertifiedKey.html>
+pub struct rustls_certified_key {
+    _private: [u8; 0],
+}
+
+impl Castable for rustls_certified_key {
+    type Ownership = OwnershipArc;
+    type RustType = CertifiedKey;
 }
 
 impl rustls_certified_key {
@@ -270,14 +281,19 @@ impl rustls_certified_key {
     }
 }
 
-box_castable! {
-    /// A `rustls_root_cert_store` being constructed.
-    ///
-    /// A builder can be modified by adding trust anchor root certificates with
-    /// `rustls_root_cert_store_builder_add_pem`. Once you're done adding root certificates,
-    /// call `rustls_root_cert_store_builder_build` to turn it into a `rustls_root_cert_store`.
-    /// This object is not safe for concurrent mutation.
-    pub struct rustls_root_cert_store_builder(Option<RootCertStoreBuilder>);
+/// A `rustls_root_cert_store` being constructed.
+///
+/// A builder can be modified by adding trust anchor root certificates with
+/// `rustls_root_cert_store_builder_add_pem`. Once you're done adding root certificates,
+/// call `rustls_root_cert_store_builder_build` to turn it into a `rustls_root_cert_store`.
+/// This object is not safe for concurrent mutation.
+pub struct rustls_root_cert_store_builder {
+    _private: [u8; 0],
+}
+
+impl Castable for rustls_root_cert_store_builder {
+    type Ownership = OwnershipBox;
+    type RustType = Option<RootCertStoreBuilder>;
 }
 
 pub(crate) struct RootCertStoreBuilder {
@@ -440,10 +456,15 @@ impl rustls_root_cert_store_builder {
     }
 }
 
-arc_castable! {
-    /// A root certificate store.
-    /// <https://docs.rs/rustls/latest/rustls/struct.RootCertStore.html>
-    pub struct rustls_root_cert_store(RootCertStore);
+/// A root certificate store.
+/// <https://docs.rs/rustls/latest/rustls/struct.RootCertStore.html>
+pub struct rustls_root_cert_store {
+    _private: [u8; 0],
+}
+
+impl Castable for rustls_root_cert_store {
+    type Ownership = OwnershipArc;
+    type RustType = RootCertStore;
 }
 
 impl rustls_root_cert_store {

librustls/src/cipher.rs

@@ -1,13 +1,18 @@
 use rustls::SupportedCipherSuite;
 
 use crate::enums::rustls_tls_version;
-use crate::ffi::{ref_castable, try_ref_from_ptr};
+use crate::ffi::{Castable, OwnershipRef, try_ref_from_ptr};
 use crate::panic::ffi_panic_boundary;
 use crate::rslice::rustls_str;
 
-ref_castable! {
-    /// A cipher suite supported by rustls.
-    pub struct rustls_supported_ciphersuite(SupportedCipherSuite);
+/// A cipher suite supported by rustls.
+pub struct rustls_supported_ciphersuite {
+    _private: [u8; 0],
+}
+
+impl Castable for rustls_supported_ciphersuite {
+    type Ownership = OwnershipRef;
+    type RustType = SupportedCipherSuite;
 }
 
 impl rustls_supported_ciphersuite {

librustls/src/client.rs

@@ -18,7 +18,7 @@ use crate::connection::{Connection, rustls_connection};
 use crate::crypto_provider::{self, rustls_crypto_provider, rustls_hpke};
 use crate::error::{self, map_error, rustls_result};
 use crate::ffi::{
-    arc_castable, box_castable, free_arc, free_box, set_arc_mut_ptr, set_boxed_mut_ptr,
+    Castable, OwnershipArc, OwnershipBox, free_arc, free_box, set_arc_mut_ptr, set_boxed_mut_ptr,
     to_boxed_mut_ptr, try_box_from_ptr, try_clone_arc, try_mut_from_ptr, try_mut_from_ptr_ptr,
     try_ref_from_ptr, try_ref_from_ptr_ptr, try_slice,
 };
@@ -29,20 +29,25 @@ use crate::rslice::{rustls_slice_bytes, rustls_slice_slice_bytes, rustls_str};
 use crate::userdata::userdata_get;
 use crate::verifier::rustls_server_cert_verifier;
 
-box_castable! {
-    /// A client config being constructed.
-    ///
-    /// A builder can be modified by, e.g. `rustls_client_config_builder_load_roots_from_file`.
-    /// Once you're done configuring settings, call `rustls_client_config_builder_build`
-    /// to turn it into a *rustls_client_config.
-    ///
-    /// Alternatively, if an error occurs or, you don't wish to build a config,
-    /// call `rustls_client_config_builder_free` to free the builder directly.
-    ///
-    /// This object is not safe for concurrent mutation. Under the hood,
-    /// it corresponds to a `Box<ClientConfig>`.
-    /// <https://docs.rs/rustls/latest/rustls/struct.ConfigBuilder.html>
-    pub struct rustls_client_config_builder(ClientConfigBuilder);
+/// A client config being constructed.
+///
+/// A builder can be modified by, e.g. `rustls_client_config_builder_load_roots_from_file`.
+/// Once you're done configuring settings, call `rustls_client_config_builder_build`
+/// to turn it into a *rustls_client_config.
+///
+/// Alternatively, if an error occurs or, you don't wish to build a config,
+/// call `rustls_client_config_builder_free` to free the builder directly.
+///
+/// This object is not safe for concurrent mutation. Under the hood,
+/// it corresponds to a `Box<ClientConfig>`.
+/// <https://docs.rs/rustls/latest/rustls/struct.ConfigBuilder.html>
+pub struct rustls_client_config_builder {
+    _private: [u8; 0],
+}
+
+impl Castable for rustls_client_config_builder {
+    type Ownership = OwnershipBox;
+    type RustType = ClientConfigBuilder;
 }
 
 pub(crate) struct ClientConfigBuilder {
@@ -76,12 +81,17 @@ impl Default for ClientConfigBuilder {
     }
 }
 
-arc_castable! {
-    /// A client config that is done being constructed and is now read-only.
-    ///
-    /// Under the hood, this object corresponds to an `Arc<ClientConfig>`.
-    /// <https://docs.rs/rustls/latest/rustls/struct.ClientConfig.html>
-    pub struct rustls_client_config(ClientConfig);
+/// A client config that is done being constructed and is now read-only.
+///
+/// Under the hood, this object corresponds to an `Arc<ClientConfig>`.
+/// <https://docs.rs/rustls/latest/rustls/struct.ClientConfig.html>
+pub struct rustls_client_config {
+    _private: [u8; 0],
+}
+
+impl Castable for rustls_client_config {
+    type Ownership = OwnershipArc;
+    type RustType = ClientConfig;
 }
 
 impl rustls_client_config_builder {

librustls/src/connection.rs

@@ -11,7 +11,7 @@ use crate::certificate::rustls_certificate;
 use crate::enums::rustls_handshake_kind;
 use crate::error::{map_error, rustls_io_result, rustls_result};
 use crate::ffi::{
-    box_castable, free_box, try_callback, try_mut_from_ptr, try_ref_from_ptr, try_slice,
+    Castable, OwnershipBox, free_box, try_callback, try_mut_from_ptr, try_ref_from_ptr, try_slice,
     try_slice_mut,
 };
 use crate::io::{
@@ -92,9 +92,14 @@ impl std::ops::DerefMut for Connection {
     }
 }
 
-box_castable! {
-    /// A C representation of a Rustls `Connection`.
-    pub struct rustls_connection(Connection);
+/// A C representation of a Rustls `Connection`.
+pub struct rustls_connection {
+    _private: [u8; 0],
+}
+
+impl Castable for rustls_connection {
+    type Ownership = OwnershipBox;
+    type RustType = Connection;
 }
 
 impl rustls_connection {