summaryrefslogtreecommitdiff
path: root/packages/taler-util/src/twrpc-impl.node.ts
blob: 30e362e5b84877cd8be4e73fef5f0263db4effc4 (plain)
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
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
/*
 This file is part of GNU Taler
 (C) 2023 Taler Systems S.A.

 GNU Taler 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, or (at your option) any later version.

 GNU Taler 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
 GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
 */

import * as net from "node:net";
import * as fs from "node:fs";
import { Logger } from "./logging.js";
import { bytesToString, typedArrayConcat } from "./taler-crypto.js";
import type { RpcConnectArgs, RpcServerArgs } from "./twrpc.js";

interface ReadLinewiseArgs {
  onLine(lineData: Uint8Array): void;
  sock: net.Socket;
}

const logger = new Logger("twrpc-impl.node.ts");

function readStreamLinewise(args: ReadLinewiseArgs): void {
  let chunks: Uint8Array[] = [];
  args.sock.on("data", (buf: Uint8Array) => {
    // Process all newlines in the newly received buffer
    while (1) {
      const newlineIdx = buf.indexOf("\n".charCodeAt(0));
      if (newlineIdx >= 0) {
        let left = buf.subarray(0, newlineIdx + 1);
        let right = buf.subarray(newlineIdx + 1);
        chunks.push(left);
        const line = typedArrayConcat(chunks);
        args.onLine(line);
        chunks = [];
        buf = right;
      } else {
        chunks.push(buf);
        break;
      }
    }
  });
}

export async function connectRpc<T>(args: RpcConnectArgs<T>): Promise<T> {
  let sockFilename = args.socketFilename;
  return new Promise((resolve, reject) => {
    const client = net.createConnection(sockFilename);
    client.on("error", (e) => {
      reject(e);
    });
    client.on("connect", () => {
      let parsingBody: string | undefined = undefined;
      let bodyChunks: string[] = [];

      logger.info("connected!");
      client.write("%hello-from-client\n");
      const res = args.onEstablished({
        sendMessage(m) {
          client.write("%request\n");
          client.write(JSON.stringify(m));
          client.write("\n");
          client.write("%end\n");
        },
        close() {
          client.destroy();
        },
      });
      readStreamLinewise({
        sock: client,
        onLine(line) {
          const lineStr = bytesToString(line);
          // Are we currently parsing the body of a request?
          if (!parsingBody) {
            const strippedLine = lineStr.trim();
            if (strippedLine == "%message") {
              parsingBody = "message";
            } else if (strippedLine == "%hello-from-server") {
            } else if (strippedLine.startsWith("%error:")) {
              client.end();
              res.onDisconnect();
            } else {
              logger.warn("got unknown request");
              client.write("%error: invalid message\n");
              client.end();
            }
          } else if (parsingBody == "message") {
            const strippedLine = lineStr.trim();
            if (strippedLine == "%end") {
              let req = bodyChunks.join("");
              let reqJson: any = undefined;
              try {
                reqJson = JSON.parse(req);
              } catch (e) {
                logger.warn("JSON message from server was invalid");
                logger.info(`message was: ${req}`);
              }
              if (reqJson !== undefined) {
                res.onMessage(reqJson);
              } else {
                client.write("%error: invalid JSON");
                client.end();
              }
              bodyChunks = [];
              parsingBody = undefined;
            } else {
              bodyChunks.push(lineStr);
            }
          } else {
            logger.info("invalid parser state");
            client.write("%error: internal error\n");
            client.end();
          }
        },
      });
      client.on("close", () => {
        res.onDisconnect();
      });
      client.on("data", () => {});
      resolve(res.result);
    });
  });
}

export async function runRpcServer(args: RpcServerArgs): Promise<void> {
  let sockFilename = args.socketFilename;
  try {
    fs.unlinkSync(sockFilename);
  } catch (e) {
    // Do nothing!
  }
  return new Promise((resolve, reject) => {
    const server = net.createServer((sock) => {
      // Are we currently parsing the body of a request?
      let parsingBody: string | undefined = undefined;
      let bodyChunks: string[] = [];

      sock.write("%hello-from-server\n");
      const handlers = args.onConnect({
        sendResponse(message) {
          sock.write("%message\n");
          sock.write(JSON.stringify(message));
          sock.write("\n");
          sock.write("%end\n");
        },
      });

      sock.on("error", (err) => {
        logger.error(`connection error: ${err}`);
      });

      function processLine(line: Uint8Array) {
        const lineStr = bytesToString(line);
        if (!parsingBody) {
          const strippedLine = lineStr.trim();
          if (strippedLine == "%request") {
            parsingBody = "request";
          } else if (strippedLine === "%hello-from-client") {
            // Nothing to do, ignore hello
          } else if (strippedLine.startsWith("%error:")) {
            logger.warn("got error from client");
            sock.end();
            handlers.onDisconnect();
          } else {
            logger.info("got unknown request");
            sock.write("%error: invalid request\n");
            sock.end();
          }
        } else if (parsingBody == "request") {
          const strippedLine = lineStr.trim();
          if (strippedLine == "%end") {
            let req = bodyChunks.join("");
            let reqJson: any = undefined;
            try {
              reqJson = JSON.parse(req);
            } catch (e) {
              logger.warn("JSON request from client was invalid");
            }
            if (reqJson !== undefined) {
              handlers.onMessage(reqJson);
            } else {
              sock.write("%error: invalid JSON");
              sock.end();
            }
            bodyChunks = [];
            parsingBody = undefined;
          } else {
            bodyChunks.push(lineStr);
          }
        } else {
          logger.error("invalid parser state");
          sock.write("%error: internal error\n");
          sock.end();
        }
      }

      readStreamLinewise({
        sock,
        onLine: processLine,
      });

      sock.on("close", (hadError: boolean) => {
        logger.trace(`connection closed, hadError=${hadError}`);
        handlers.onDisconnect();
      });
    });
    server.listen(args.socketFilename);
  });
}