lib.rs

}

#[derive(Encode, Decode)]
/// Crossing is a helper wrapping any Encode-Decodeable type
/// for transferring over the wasm barrier.
pub struct Crossing<T: Encode + Decode>(T);

impl<T: Encode + Decode> PassBy for Crossing<T> {
	type PassBy = sp_runtime_interface::pass_by::Codec<Self>;
}

impl<T: Encode + Decode> Crossing<T> {

	/// Convert into the inner type
	pub fn into_inner(self) -> T {
		self.0
	}
}

// useful for testing
impl<T> core::default::Default for Crossing<T>
	where T: core::default::Default + Encode + Decode
{
	fn default() -> Self {
		Self(Default::default())
	}

}

/// Interface to provide tracing facilities for wasm. Modelled after tokios `tracing`-crate
/// interfaces. See `sp-tracing` for more information.
#[runtime_interface(wasm_only, no_tracing)]
pub trait WasmTracing {
	/// Whether the span described in `WasmMetadata` should be traced wasm-side
	/// On the host converts into a static Metadata and checks against the global `tracing` dispatcher.
	///
	/// When returning false the calling code should skip any tracing-related execution. In general
	/// within the same block execution this is not expected to change and it doesn't have to be
	/// checked more than once per metadata. This exists for optimisation purposes but is still not
	/// cheap as it will jump the wasm-native-barrier every time it is called. So an implementation might
	/// chose to cache the result for the execution of the entire block.
	fn enabled(&mut self, metadata: Crossing<sp_tracing::WasmMetadata>) -> bool {
		let metadata: &tracing_core::metadata::Metadata<'static> = (&metadata.into_inner()).into();
		tracing::dispatcher::get_default(|d| {
			d.enabled(metadata)
		})
	}

	/// Open a new span with the given attributes. Return the u64 Id of the span.
	///
	/// On the native side this goes through the default `tracing` dispatcher to register the span
	/// and then calls `clone_span` with the ID to signal that we are keeping it around on the wasm-
	/// side even after the local span is dropped. The resulting ID is then handed over to the wasm-
	/// side.
	fn enter_span(&mut self, span: Crossing<sp_tracing::WasmEntryAttributes>) -> u64 {
		let span: tracing::Span = span.into_inner().into();
		match span.id() {
			Some(id) => tracing::dispatcher::get_default(|d| {
				// inform dispatch that we'll keep the ID around
				// then enter it immediately
				let final_id = d.clone_span(&id);
				d.enter(&final_id);
				final_id.into_u64()
			}),
			_ => {
				0
			}
		}
	}

	/// Emit the given event to the global tracer on the native side
	fn event(&mut self, event: Crossing<sp_tracing::WasmEntryAttributes>) {
		event.into_inner().emit();
	}

	/// Signal that a given span-id has been exited. On native, this directly
	/// proxies the span to the global dispatcher.
	fn exit(&mut self, span: u64) {
		tracing::dispatcher::get_default(|d| {
			let id = tracing_core::span::Id::from_u64(span);
			d.exit(&id);
		});
	}
}

#[cfg(all(not(feature="std"), feature="with-tracing"))]
mod tracing_setup {
	use core::sync::atomic::{AtomicBool, Ordering};
	use tracing_core::{
		dispatcher::{Dispatch, set_global_default},
		span::{Id, Record, Attributes},
		Metadata, Event,
	};
	use super::{wasm_tracing, Crossing};

	const TRACING_SET : AtomicBool = AtomicBool::new(false);


	/// The PassingTracingSubscriber implements `tracing_core::Subscriber`
	/// and pushes the information across the runtime interface to the host
	struct PassingTracingSubsciber;

	impl tracing_core::Subscriber for PassingTracingSubsciber {
		fn enabled(&self, metadata: &Metadata<'_>) -> bool {
			wasm_tracing::enabled(Crossing(metadata.into()))
		}
		fn new_span(&self, attrs: &Attributes<'_>) -> Id {
			Id::from_u64(wasm_tracing::enter_span(Crossing(attrs.into())))
		}
		fn enter(&self, span: &Id) {
			// Do nothing, we already entered the span previously
		}
		/// Not implemented! We do not support recording values later
		/// Will panic when used.
		fn record(&self, span: &Id, values: &Record<'_>) {
			unimplemented!{} // this usage is not supported
		}
		/// Not implemented! We do not support recording values later
		/// Will panic when used.
		fn record_follows_from(&self, span: &Id, follows: &Id) {
			unimplemented!{ } // this usage is not supported
		}
		fn event(&self, event: &Event<'_>) {
			wasm_tracing::event(Crossing(event.into()))
		}
		fn exit(&self, span: &Id) {
			wasm_tracing::exit(span.into_u64())
		}
	}


	/// Initialize tracing of sp_tracing on wasm with `with-tracing` enabled.
	/// Can be called multiple times from within the same process and will only
	/// set the global bridging subscriber once.
	pub fn init_tracing() {
		if TRACING_SET.load(Ordering::Relaxed) == false {
			set_global_default(Dispatch::new(PassingTracingSubsciber {}))
				.expect("We only ever call this once");
			TRACING_SET.store(true, Ordering::Relaxed);
		}
	}
}

#[cfg(not(all(not(feature="std"), feature="with-tracing")))]
mod tracing_setup {
	/// Initialize tracing of sp_tracing not necessary – noop. To enable build
	/// without std and with the `with-tracing`-feature.
	pub fn init_tracing() { }
}

pub use tracing_setup::init_tracing;

/// Wasm-only interface that provides functions for interacting with the sandbox.
#[runtime_interface(wasm_only)]
pub trait Sandbox {
	/// Instantiate a new sandbox instance with the given `wasm_code`.
	fn instantiate(
		&mut self,
		dispatch_thunk: u32,
		wasm_code: &[u8],
		env_def: &[u8],
		state_ptr: Pointer<u8>,
	) -> u32 {
		self.sandbox()
			.instance_new(dispatch_thunk, wasm_code, env_def, state_ptr.into())
			.expect("Failed to instantiate a new sandbox")
	}

	/// Invoke `function` in the sandbox with `sandbox_idx`.
	fn invoke(
		&mut self,
		instance_idx: u32,
		function: &str,
		args: &[u8],
		return_val_ptr: Pointer<u8>,
		return_val_len: u32,
		state_ptr: Pointer<u8>,
	) -> u32 {
		self.sandbox().invoke(
			instance_idx,
			&function,
			&args,
			return_val_ptr,
			return_val_len,
			state_ptr.into(),
		).expect("Failed to invoke function with sandbox")
	}

	/// Create a new memory instance with the given `initial` and `maximum` size.
	fn memory_new(&mut self, initial: u32, maximum: u32) -> u32 {
		self.sandbox()
			.memory_new(initial, maximum)
			.expect("Failed to create new memory with sandbox")
	}

	/// Get the memory starting at `offset` from the instance with `memory_idx` into the buffer.
	fn memory_get(
		&mut self,
		memory_idx: u32,
		offset: u32,
		buf_ptr: Pointer<u8>,
		buf_len: u32,
	) -> u32 {
		self.sandbox()
			.memory_get(memory_idx, offset, buf_ptr, buf_len)
			.expect("Failed to get memory with sandbox")
	}

	/// Set the memory in the given `memory_idx` to the given value at `offset`.
	fn memory_set(
		&mut self,
		memory_idx: u32,
		offset: u32,
		val_ptr: Pointer<u8>,
		val_len: u32,
	) -> u32 {
		self.sandbox()
			.memory_set(memory_idx, offset, val_ptr, val_len)
			.expect("Failed to set memory with sandbox")
	}

	/// Teardown the memory instance with the given `memory_idx`.
	fn memory_teardown(&mut self, memory_idx: u32) {
		self.sandbox().memory_teardown(memory_idx).expect("Failed to teardown memory with sandbox")
	}

	/// Teardown the sandbox instance with the given `instance_idx`.
	fn instance_teardown(&mut self, instance_idx: u32) {
		self.sandbox().instance_teardown(instance_idx).expect("Failed to teardown sandbox instance")
	}

	/// Get the value from a global with the given `name`. The sandbox is determined by the given
	/// `instance_idx`.
	///
	/// Returns `Some(_)` when the requested global variable could be found.
	fn get_global_val(&mut self, instance_idx: u32, name: &str) -> Option<sp_wasm_interface::Value> {
		self.sandbox().get_global_val(instance_idx, name).expect("Failed to get global from sandbox")
	}
}

/// Wasm host functions for managing tasks.
///
/// This should not be used directly. Use `sp_tasks` for running parallel tasks instead.
#[runtime_interface(wasm_only)]
pub trait RuntimeTasks {
	/// Wasm host function for spawning task.
	///
	/// This should not be used directly. Use `sp_tasks::spawn` instead.
	fn spawn(dispatcher_ref: u32, entry: u32, payload: Vec<u8>) -> u64 {
		sp_externalities::with_externalities(|mut ext|{
			let runtime_spawn = ext.extension::<RuntimeSpawnExt>()
				.expect("Cannot spawn without dynamic runtime dispatcher (RuntimeSpawnExt)");
			runtime_spawn.spawn_call(dispatcher_ref, entry, payload)
		}).expect("`RuntimeTasks::spawn`: called outside of externalities context")
	}

	/// Wasm host function for joining a task.
	///
	/// This should not be used directly. Use `join` of `sp_tasks::spawn` result instead.
	fn join(handle: u64) -> Vec<u8> {
		sp_externalities::with_externalities(|mut ext| {
			let runtime_spawn = ext.extension::<RuntimeSpawnExt>()
				.expect("Cannot join without dynamic runtime dispatcher (RuntimeSpawnExt)");
			runtime_spawn.join(handle)
		}).expect("`RuntimeTasks::join`: called outside of externalities context")
	}
 }

/// Allocator used by Substrate when executing the Wasm runtime.
#[cfg(not(feature = "std"))]
struct WasmAllocator;

#[cfg(all(not(feature = "disable_allocator"), not(feature = "std")))]
#[global_allocator]
static ALLOCATOR: WasmAllocator = WasmAllocator;

#[cfg(not(feature = "std"))]
mod allocator_impl {
	use super::*;
	use core::alloc::{GlobalAlloc, Layout};

	unsafe impl GlobalAlloc for WasmAllocator {
		unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
			allocator::malloc(layout.size() as u32)
		}

		unsafe fn dealloc(&self, ptr: *mut u8, _: Layout) {
			allocator::free(ptr)
		}
	}
}

/// A default panic handler for WASM environment.
#[cfg(all(not(feature = "disable_panic_handler"), not(feature = "std")))]
#[panic_handler]
#[no_mangle]
pub fn panic(info: &core::panic::PanicInfo) -> ! {
	unsafe {
		let message = sp_std::alloc::format!("{}", info);
		logging::log(LogLevel::Error, "runtime", message.as_bytes());
		core::arch::wasm32::unreachable();
	}
}

/// A default OOM handler for WASM environment.
#[cfg(all(not(feature = "disable_oom"), not(feature = "std")))]
#[alloc_error_handler]
pub fn oom(_: core::alloc::Layout) -> ! {
	unsafe {
		logging::log(LogLevel::Error, "runtime", b"Runtime memory exhausted. Aborting");
		core::arch::wasm32::unreachable();
	}
}

/// Type alias for Externalities implementation used in tests.
#[cfg(feature = "std")]
pub type TestExternalities = sp_state_machine::TestExternalities<sp_core::Blake2Hasher, u64>;

/// The host functions Substrate provides for the Wasm runtime environment.
///
/// All these host functions will be callable from inside the Wasm environment.
#[cfg(feature = "std")]
pub type SubstrateHostFunctions = (
	storage::HostFunctions,
	default_child_storage::HostFunctions,
	misc::HostFunctions,
	wasm_tracing::HostFunctions,
	offchain::HostFunctions,
	crypto::HostFunctions,
	hashing::HostFunctions,
	allocator::HostFunctions,
	logging::HostFunctions,
	sandbox::HostFunctions,
	crate::trie::HostFunctions,
	offchain_index::HostFunctions,
	runtime_tasks::HostFunctions,
);

#[cfg(test)]
mod tests {
	use super::*;
	use sp_state_machine::BasicExternalities;
	use sp_core::{
		storage::Storage, map, traits::TaskExecutorExt, testing::TaskExecutor,
	};
	use std::any::TypeId;

	#[test]
	fn storage_works() {
		let mut t = BasicExternalities::default();
		t.execute_with(|| {
			assert_eq!(storage::get(b"hello"), None);
			storage::set(b"hello", b"world");
			assert_eq!(storage::get(b"hello"), Some(b"world".to_vec()));
			assert_eq!(storage::get(b"foo"), None);
			storage::set(b"foo", &[1, 2, 3][..]);
		});

		t = BasicExternalities::new(Storage {
			top: map![b"foo".to_vec() => b"bar".to_vec()],
			children_default: map![],
		});

		t.execute_with(|| {
			assert_eq!(storage::get(b"hello"), None);
			assert_eq!(storage::get(b"foo"), Some(b"bar".to_vec()));
		});
	}

	#[test]
	fn read_storage_works() {
		let value = b"\x0b\0\0\0Hello world".to_vec();
		let mut t = BasicExternalities::new(Storage {
			top: map![b":test".to_vec() => value.clone()],
			children_default: map![],
		});

		t.execute_with(|| {
			let mut v = [0u8; 4];
			assert_eq!(storage::read(b":test", &mut v[..], 0).unwrap(), value.len() as u32);
			assert_eq!(v, [11u8, 0, 0, 0]);
			let mut w = [0u8; 11];
			assert_eq!(storage::read(b":test", &mut w[..], 4).unwrap(), value.len() as u32 - 4);
			assert_eq!(&w, b"Hello world");
		});
	}

	#[test]
	fn clear_prefix_works() {
		let mut t = BasicExternalities::new(Storage {
			top: map![
				b":a".to_vec() => b"\x0b\0\0\0Hello world".to_vec(),
				b":abcd".to_vec() => b"\x0b\0\0\0Hello world".to_vec(),
				b":abc".to_vec() => b"\x0b\0\0\0Hello world".to_vec(),
				b":abdd".to_vec() => b"\x0b\0\0\0Hello world".to_vec()
			],
			children_default: map![],
		});

		t.execute_with(|| {
			storage::clear_prefix(b":abc");

			assert!(storage::get(b":a").is_some());
			assert!(storage::get(b":abdd").is_some());
			assert!(storage::get(b":abcd").is_none());
			assert!(storage::get(b":abc").is_none());
		});
	}

	#[test]
	fn batch_verify_start_finish_works() {
		let mut ext = BasicExternalities::default();
		ext.register_extension(TaskExecutorExt::new(TaskExecutor::new()));

		ext.execute_with(|| {
			crypto::start_batch_verify();
		});

		assert!(ext.extensions().get_mut(TypeId::of::<VerificationExt>()).is_some());

		ext.execute_with(|| {
			assert!(crypto::finish_batch_verify());
		});

		assert!(ext.extensions().get_mut(TypeId::of::<VerificationExt>()).is_none());
	}

	#[test]
	fn long_sr25519_batching() {
		let mut ext = BasicExternalities::default();
		ext.register_extension(TaskExecutorExt::new(TaskExecutor::new()));
		ext.execute_with(|| {
			let pair = sr25519::Pair::generate_with_phrase(None).0;
			crypto::start_batch_verify();
			for it in 0..70 {
				let msg = format!("Schnorrkel {}!", it);
				let signature = pair.sign(msg.as_bytes());
				crypto::sr25519_batch_verify(&signature, msg.as_bytes(), &pair.public());
			}

			// push invlaid
			crypto::sr25519_batch_verify(
				&Default::default(),
				&Vec::new(),
				&Default::default(),
			);
			assert!(!crypto::finish_batch_verify());

			crypto::start_batch_verify();
			for it in 0..70 {
				let msg = format!("Schnorrkel {}!", it);
				let signature = pair.sign(msg.as_bytes());
				crypto::sr25519_batch_verify(&signature, msg.as_bytes(), &pair.public());
			}
			assert!(crypto::finish_batch_verify());
		});
	}

	#[test]
	fn batching_works() {
		let mut ext = BasicExternalities::default();
		ext.register_extension(TaskExecutorExt::new(TaskExecutor::new()));
		ext.execute_with(|| {
			// invalid ed25519 signature
			crypto::start_batch_verify();
			crypto::ed25519_batch_verify(
				&Default::default(),
				&Vec::new(),
				&Default::default(),
			);
			assert!(!crypto::finish_batch_verify());

			// 2 valid ed25519 signatures
			crypto::start_batch_verify();

			let pair = ed25519::Pair::generate_with_phrase(None).0;
			let msg = b"Important message";
			let signature = pair.sign(msg);
			crypto::ed25519_batch_verify(&signature, msg, &pair.public());

			let pair = ed25519::Pair::generate_with_phrase(None).0;
			let msg = b"Even more important message";
			let signature = pair.sign(msg);
			crypto::ed25519_batch_verify(&signature, msg, &pair.public());

			assert!(crypto::finish_batch_verify());

			// 1 valid, 1 invalid ed25519 signature
			crypto::start_batch_verify();

			let pair = ed25519::Pair::generate_with_phrase(None).0;
			let msg = b"Important message";
			let signature = pair.sign(msg);
			crypto::ed25519_batch_verify(&signature, msg, &pair.public());

			crypto::ed25519_batch_verify(
				&Default::default(),
				&Vec::new(),
				&Default::default(),
			);

			assert!(!crypto::finish_batch_verify());

			// 1 valid ed25519, 2 valid sr25519
			crypto::start_batch_verify();

			let pair = ed25519::Pair::generate_with_phrase(None).0;
			let msg = b"Ed25519 batching";
			let signature = pair.sign(msg);
			crypto::ed25519_batch_verify(&signature, msg, &pair.public());

			let pair = sr25519::Pair::generate_with_phrase(None).0;
			let msg = b"Schnorrkel rules";
			let signature = pair.sign(msg);
			crypto::sr25519_batch_verify(&signature, msg, &pair.public());

			let pair = sr25519::Pair::generate_with_phrase(None).0;
			let msg = b"Schnorrkel batches!";
			let signature = pair.sign(msg);
			crypto::sr25519_batch_verify(&signature, msg, &pair.public());

			assert!(crypto::finish_batch_verify());

			// 1 valid sr25519, 1 invalid sr25519
			crypto::start_batch_verify();

			let pair = sr25519::Pair::generate_with_phrase(None).0;
			let msg = b"Schnorrkcel!";
			let signature = pair.sign(msg);
			crypto::sr25519_batch_verify(&signature, msg, &pair.public());

			crypto::sr25519_batch_verify(
				&Default::default(),
				&Vec::new(),
				&Default::default(),
			);

			assert!(!crypto::finish_batch_verify());
		});
	}
}