_ Git - rust-lightning/blob - lightning-block-sync/src/rpc.rs

   1 use crate::{BlockHeaderData, BlockSource, AsyncBlockSourceResult};
   2 use crate::http::{HttpClient, HttpEndpoint, JsonResponse};
   3
   4 use bitcoin::blockdata::block::Block;
   5 use bitcoin::hash_types::BlockHash;
   6 use bitcoin::hashes::hex::ToHex;
   7
   8 use serde_json;
   9
  10 use std::convert::TryFrom;
  11 use std::convert::TryInto;
  12 use std::sync::atomic::{AtomicUsize, Ordering};
  13
  14 /// A simple RPC client for calling methods using HTTP `POST`.
  15 pub struct RpcClient {
  16         basic_auth: String,
  17         endpoint: HttpEndpoint,
  18         client: HttpClient,
  19         id: AtomicUsize,
  20 }
  21
  22 impl RpcClient {
  23         /// Creates a new RPC client connected to the given endpoint with the provided credentials. The
  24         /// credentials should be a base64 encoding of a user name and password joined by a colon, as is
  25         /// required for HTTP basic access authentication.
  26         pub fn new(credentials: &str, endpoint: HttpEndpoint) -> std::io::Result<Self> {
  27                 let client = HttpClient::connect(&endpoint)?;
  28                 Ok(Self {
  29                         basic_auth: "Basic ".to_string() + credentials,
  30                         endpoint,
  31                         client,
  32                         id: AtomicUsize::new(0),
  33                 })
  34         }
  35
  36         /// Calls a method with the response encoded in JSON format and interpreted as type `T`.
  37         pub async fn call_method<T>(&mut self, method: &str, params: &[serde_json::Value]) -> std::io::Result<T>
  38         where JsonResponse: TryFrom<Vec<u8>, Error = std::io::Error> + TryInto<T, Error = std::io::Error> {
  39                 let host = format!("{}:{}", self.endpoint.host(), self.endpoint.port());
  40                 let uri = self.endpoint.path();
  41                 let content = serde_json::json!({
  42                         "method": method,
  43                         "params": params,
  44                         "id": &self.id.fetch_add(1, Ordering::AcqRel).to_string()
  45                 });
  46
  47                 let mut response = self.client.post::<JsonResponse>(&uri, &host, &self.basic_auth, content)
  48                         .await?.0;
  49                 if !response.is_object() {
  50                         return Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "expected JSON object"));
  51                 }
  52
  53                 let error = &response["error"];
  54                 if !error.is_null() {
  55                         // TODO: Examine error code for a more precise std::io::ErrorKind.
  56                         let message = error["message"].as_str().unwrap_or("unknown error");
  57                         return Err(std::io::Error::new(std::io::ErrorKind::Other, message));
  58                 }
  59
  60                 let result = &mut response["result"];
  61                 if result.is_null() {
  62                         return Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "expected JSON result"));
  63                 }
  64
  65                 JsonResponse(result.take()).try_into()
  66         }
  67 }
  68
  69 impl BlockSource for RpcClient {
  70         fn get_header<'a>(&'a mut self, header_hash: &'a BlockHash, _height: Option<u32>) -> AsyncBlockSourceResult<'a, BlockHeaderData> {
  71                 Box::pin(async move {
  72                         let header_hash = serde_json::json!(header_hash.to_hex());
  73                         Ok(self.call_method("getblockheader", &[header_hash]).await?)
  74                 })
  75         }
  76
  77         fn get_block<'a>(&'a mut self, header_hash: &'a BlockHash) -> AsyncBlockSourceResult<'a, Block> {
  78                 Box::pin(async move {
  79                         let header_hash = serde_json::json!(header_hash.to_hex());
  80                         let verbosity = serde_json::json!(0);
  81                         Ok(self.call_method("getblock", &[header_hash, verbosity]).await?)
  82                 })
  83         }
  84
  85         fn get_best_block<'a>(&'a mut self) -> AsyncBlockSourceResult<'a, (BlockHash, Option<u32>)> {
  86                 Box::pin(async move {
  87                         Ok(self.call_method("getblockchaininfo", &[]).await?)
  88                 })
  89         }
  90 }
  91
  92 #[cfg(test)]
  93 mod tests {
  94         use super::*;
  95         use crate::http::client_tests::{HttpServer, MessageBody};
  96
  97         /// Credentials encoded in base64.
  98         const CREDENTIALS: &'static str = "dXNlcjpwYXNzd29yZA==";
  99
 100         /// Converts a JSON value into `u64`.
 101         impl TryInto<u64> for JsonResponse {
 102                 type Error = std::io::Error;
 103
 104                 fn try_into(self) -> std::io::Result<u64> {
 105                         match self.0.as_u64() {
 106                                 None => Err(std::io::Error::new(std::io::ErrorKind::InvalidData, "not a number")),
 107                                 Some(n) => Ok(n),
 108                         }
 109                 }
 110         }
 111
 112         #[tokio::test]
 113         async fn call_method_returning_unknown_response() {
 114                 let server = HttpServer::responding_with_not_found();
 115                 let mut client = RpcClient::new(CREDENTIALS, server.endpoint()).unwrap();
 116
 117                 match client.call_method::<u64>("getblockcount", &[]).await {
 118                         Err(e) => assert_eq!(e.kind(), std::io::ErrorKind::NotFound),
 119                         Ok(_) => panic!("Expected error"),
 120                 }
 121         }
 122
 123         #[tokio::test]
 124         async fn call_method_returning_malfomred_response() {
 125                 let response = serde_json::json!("foo");
 126                 let server = HttpServer::responding_with_ok(MessageBody::Content(response));
 127                 let mut client = RpcClient::new(CREDENTIALS, server.endpoint()).unwrap();
 128
 129                 match client.call_method::<u64>("getblockcount", &[]).await {
 130                         Err(e) => {
 131                                 assert_eq!(e.kind(), std::io::ErrorKind::InvalidData);
 132                                 assert_eq!(e.get_ref().unwrap().to_string(), "expected JSON object");
 133                         },
 134                         Ok(_) => panic!("Expected error"),
 135                 }
 136         }
 137
 138         #[tokio::test]
 139         async fn call_method_returning_error() {
 140                 let response = serde_json::json!({
 141                         "error": { "code": -8, "message": "invalid parameter" },
 142                 });
 143                 let server = HttpServer::responding_with_ok(MessageBody::Content(response));
 144                 let mut client = RpcClient::new(CREDENTIALS, server.endpoint()).unwrap();
 145
 146                 let invalid_block_hash = serde_json::json!("foo");
 147                 match client.call_method::<u64>("getblock", &[invalid_block_hash]).await {
 148                         Err(e) => {
 149                                 assert_eq!(e.kind(), std::io::ErrorKind::Other);
 150                                 assert_eq!(e.get_ref().unwrap().to_string(), "invalid parameter");
 151                         },
 152                         Ok(_) => panic!("Expected error"),
 153                 }
 154         }
 155
 156         #[tokio::test]
 157         async fn call_method_returning_missing_result() {
 158                 let response = serde_json::json!({ "result": null });
 159                 let server = HttpServer::responding_with_ok(MessageBody::Content(response));
 160                 let mut client = RpcClient::new(CREDENTIALS, server.endpoint()).unwrap();
 161
 162                 match client.call_method::<u64>("getblockcount", &[]).await {
 163                         Err(e) => {
 164                                 assert_eq!(e.kind(), std::io::ErrorKind::InvalidData);
 165                                 assert_eq!(e.get_ref().unwrap().to_string(), "expected JSON result");
 166                         },
 167                         Ok(_) => panic!("Expected error"),
 168                 }
 169         }
 170
 171         #[tokio::test]
 172         async fn call_method_returning_malformed_result() {
 173                 let response = serde_json::json!({ "result": "foo" });
 174                 let server = HttpServer::responding_with_ok(MessageBody::Content(response));
 175                 let mut client = RpcClient::new(CREDENTIALS, server.endpoint()).unwrap();
 176
 177                 match client.call_method::<u64>("getblockcount", &[]).await {
 178                         Err(e) => {
 179                                 assert_eq!(e.kind(), std::io::ErrorKind::InvalidData);
 180                                 assert_eq!(e.get_ref().unwrap().to_string(), "not a number");
 181                         },
 182                         Ok(_) => panic!("Expected error"),
 183                 }
 184         }
 185
 186         #[tokio::test]
 187         async fn call_method_returning_valid_result() {
 188                 let response = serde_json::json!({ "result": 654470 });
 189                 let server = HttpServer::responding_with_ok(MessageBody::Content(response));
 190                 let mut client = RpcClient::new(CREDENTIALS, server.endpoint()).unwrap();
 191
 192                 match client.call_method::<u64>("getblockcount", &[]).await {
 193                         Err(e) => panic!("Unexpected error: {:?}", e),
 194                         Ok(count) => assert_eq!(count, 654470),
 195                 }
 196         }
 197 }