1  // Copyright (c) 2025-2026 ACDC Network
 2  // This file is part of the alphaos library.
 3  //
 4  // Alpha Chain | Delta Chain Protocol
 5  // International Monetary Graphite.
 6  //
 7  // Derived from Aleo (https://aleo.org) and ProvableHQ (https://provable.com).
 8  // They built world-class ZK infrastructure. We installed the EASY button.
 9  // Their cryptography: elegant. Our modifications: bureaucracy-compatible.
10  // Original brilliance: theirs. Robert's Rules: ours. Bugs: definitely ours.
11  //
12  // Original Aleo/ProvableHQ code subject to Apache 2.0 https://www.apache.org/licenses/LICENSE-2.0
13  // All modifications and new work: CC0 1.0 Universal Public Domain Dedication.
14  // No rights reserved. No permission required. No warranty. No refunds.
15  //
16  // https://creativecommons.org/publicdomain/zero/1.0/
17  // SPDX-License-Identifier: CC0-1.0
18  
19  use std::{
20      io::{self, ErrorKind::*},
21      net::{IpAddr, Ipv4Addr, SocketAddr},
22  };
23  
24  #[cfg(doc)]
25  use crate::protocols::{self, Handshake, Reading, Writing};
26  
27  /// The Tcp's configuration. See the source of [`Config::default`] for the defaults.
28  #[derive(Debug, Clone)]
29  pub struct Config {
30      /// A user-friendly identifier of the Tcp. It is visible in the logs, where it allows Tcp instances to be
31      /// distinguished more easily if multiple are run at the same time.
32      ///
33      /// note: If set to `None` when the configuration is initially created, it will be automatically assigned
34      /// (the string representation of) a sequential, zero-based numeric identifier. So this is essentially never
35      /// `None`, in a running node.
36      pub name: Option<String>,
37      /// The IP address the Tcp's connection listener should bind to.
38      ///
39      /// note: If set to `None`, the Tcp will not listen for inbound connections at all.
40      pub listener_ip: Option<IpAddr>,
41      /// The desired listening port of the Tcp. If [`Config::allow_random_port`] is set to `true`, the Tcp
42      /// will attempt to bind its listener to a different port if the desired one is not available.
43      ///
44      /// note: [`Config::listener_ip`] must not be `None` in order for it to have any effect.
45      pub desired_listening_port: Option<u16>,
46      /// Allow listening on a different port if [`Config::desired_listening_port`] is unavailable.
47      ///
48      /// note: [`Config::listener_ip`] must not be `None` in order for it to have any effect.
49      pub allow_random_port: bool,
50      /// The list of IO errors considered fatal and causing the connection to be dropped.
51      ///
52      /// note: Tcp needs to implement the [`Reading`] and/or [`Writing`] protocol in order for it to have any effect.
53      pub fatal_io_errors: Vec<io::ErrorKind>,
54      /// The maximum number of active connections Tcp can maintain at any given time.
55      ///
56      /// note: This number can very briefly be breached by 1 in case of inbound connection attempts. It can never be
57      /// breached by outbound connection attempts, though.
58      pub max_connections: u16,
59      /// The maximum time (in milliseconds) allowed to establish a raw (before the [`Handshake`] protocol) TCP connection.
60      pub connection_timeout_ms: u16,
61  }
62  
63  impl Config {
64      /// Initializes a new Tcp configuration with a listener address,
65      /// a maximum number of connections, and the default values.
66      pub fn new(listener_address: SocketAddr, max_connections: u16) -> Self {
67          Self {
68              listener_ip: Some(listener_address.ip()),
69              desired_listening_port: Some(listener_address.port()),
70              max_connections,
71              ..Default::default()
72          }
73      }
74  }
75  
76  impl Default for Config {
77      /// Initializes a new Tcp configuration with the default values.
78      fn default() -> Self {
79          fn default_ip() -> Option<IpAddr> {
80              Some(IpAddr::V4(Ipv4Addr::UNSPECIFIED))
81          }
82  
83          Self {
84              name: None,
85              listener_ip: default_ip(),
86              desired_listening_port: None,
87              allow_random_port: true,
88              fatal_io_errors: vec![ConnectionReset, ConnectionAborted, BrokenPipe, InvalidData, UnexpectedEof],
89              max_connections: 100,
90              connection_timeout_ms: 1_000,
91          }
92      }
93  }