1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161

// This file is part of Substrate.

// Copyright (C) 2017-2020 Parity Technologies (UK) Ltd.
// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.

//! Substrate RPC servers.

#![warn(missing_docs)]

mod middleware;

use std::io;
use jsonrpc_core::{IoHandlerExtension, MetaIoHandler};
use log::error;
use pubsub::PubSubMetadata;

/// Maximal payload accepted by RPC servers.
const MAX_PAYLOAD: usize = 15 * 1024 * 1024;

/// Default maximum number of connections for WS RPC servers.
const WS_MAX_CONNECTIONS: usize = 100;

/// The RPC IoHandler containing all requested APIs.
pub type RpcHandler<T> = pubsub::PubSubHandler<T, RpcMiddleware>;

pub use self::inner::*;
pub use middleware::{RpcMiddleware, RpcMetrics};

/// Construct rpc `IoHandler`
pub fn rpc_handler<M: PubSubMetadata>(
	extension: impl IoHandlerExtension<M>,
	rpc_middleware: RpcMiddleware,
) -> RpcHandler<M> {
	let io_handler = MetaIoHandler::with_middleware(rpc_middleware);
	let mut io = pubsub::PubSubHandler::new(io_handler);
	extension.augment(&mut io);

	// add an endpoint to list all available methods.
	let mut methods = io.iter().map(|x| x.0.clone()).collect::<Vec<String>>();
	io.add_method("rpc_methods", {
		methods.sort();
		let methods = serde_json::to_value(&methods)
			.expect("Serialization of Vec<String> is infallible; qed");

		move |_| Ok(serde_json::json!({
			"version": 1,
			"methods": methods.clone(),
		}))
	});
	io
}

#[cfg(not(target_os = "unknown"))]
mod inner {
	use super::*;

	/// Type alias for ipc server
	pub type IpcServer = ipc::Server;
	/// Type alias for http server
	pub type HttpServer = http::Server;
	/// Type alias for ws server
	pub type WsServer = ws::Server;

	/// Start HTTP server listening on given address.
	///
	/// **Note**: Only available if `not(target_os = "unknown")`.
	pub fn start_http<M: pubsub::PubSubMetadata + Default>(
		addr: &std::net::SocketAddr,
		cors: Option<&Vec<String>>,
		io: RpcHandler<M>,
	) -> io::Result<http::Server> {
		http::ServerBuilder::new(io)
			.threads(4)
			.health_api(("/health", "system_health"))
			.allowed_hosts(hosts_filtering(cors.is_some()))
			.rest_api(if cors.is_some() {
				http::RestApi::Secure
			} else {
				http::RestApi::Unsecure
			})
			.cors(map_cors::<http::AccessControlAllowOrigin>(cors))
			.max_request_body_size(MAX_PAYLOAD)
			.start_http(addr)
	}

	/// Start IPC server listening on given path.
	///
	/// **Note**: Only available if `not(target_os = "unknown")`.
	pub fn start_ipc<M: pubsub::PubSubMetadata + Default>(
		addr: &str,
		io: RpcHandler<M>,
	) -> io::Result<ipc::Server> {
		let builder = ipc::ServerBuilder::new(io);
		#[cfg(target_os = "unix")]
		builder.set_security_attributes({
			let security_attributes = ipc::SecurityAttributes::empty();
			security_attributes.set_mode(0o600)?;
			security_attributes
		});
		builder.start(addr)
	}

	/// Start WS server listening on given address.
	///
	/// **Note**: Only available if `not(target_os = "unknown")`.
	pub fn start_ws<M: pubsub::PubSubMetadata + From<jsonrpc_core::futures::sync::mpsc::Sender<String>>> (
		addr: &std::net::SocketAddr,
		max_connections: Option<usize>,
		cors: Option<&Vec<String>>,
		io: RpcHandler<M>,
	) -> io::Result<ws::Server> {
		ws::ServerBuilder::with_meta_extractor(io, |context: &ws::RequestContext| context.sender().into())
			.max_payload(MAX_PAYLOAD)
			.max_connections(max_connections.unwrap_or(WS_MAX_CONNECTIONS))
			.allowed_origins(map_cors(cors))
			.allowed_hosts(hosts_filtering(cors.is_some()))
			.start(addr)
			.map_err(|err| match err {
				ws::Error::Io(io) => io,
				ws::Error::ConnectionClosed => io::ErrorKind::BrokenPipe.into(),
				e => {
					error!("{}", e);
					io::ErrorKind::Other.into()
				}
			})
	}

	fn map_cors<T: for<'a> From<&'a str>>(
		cors: Option<&Vec<String>>
	) -> http::DomainsValidation<T> {
		cors.map(|x| x.iter().map(AsRef::as_ref).map(Into::into).collect::<Vec<_>>()).into()
	}

	fn hosts_filtering(enable: bool) -> http::DomainsValidation<http::Host> {
		if enable {
			// NOTE The listening address is whitelisted by default.
			// Setting an empty vector here enables the validation
			// and allows only the listening address.
			http::DomainsValidation::AllowOnly(vec![])
		} else {
			http::DomainsValidation::Disabled
		}
	}
}

#[cfg(target_os = "unknown")]
mod inner {
}