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

use std::{net::SocketAddr, sync::Arc, time::Duration};

use smol::{future::Boxed, net::TcpStream};

use crate::{runtime, tcp::TcpClientBackhaul, Session, StatsGatherer};

mod inner;
mod worker;

/// Configuration of a client.
#[derive(Clone)]
pub struct ClientConfig {
    pub server_addr: SocketAddr,
    pub server_pk: x25519_dalek::PublicKey,
    pub gather: Arc<StatsGatherer>,
    pub protocol: Protocol,
    pub shard_count: usize,
    pub reset_interval: Option<Duration>,
}

impl ClientConfig {
    /// Creates a new ClientConfig.
    pub fn new(
        protocol: Protocol,
        server_addr: SocketAddr,
        server_pk: x25519_dalek::PublicKey,
        gather: Arc<StatsGatherer>,
    ) -> Self {
        Self {
            server_addr,
            server_pk,
            gather,
            protocol,
            shard_count: 1,
            reset_interval: None,
        }
    }

    /// Builds a Session out of this ClientConfig.
    pub async fn connect(self) -> std::io::Result<Session> {
        let server_addr = self.server_addr;
        let server_pk = self.server_pk;
        inner::connect_custom(inner::LowlevelClientConfig {
            server_addr,
            server_pubkey: server_pk,
            backhaul_gen: match self.protocol {
                Protocol::DirectTcp => Arc::new(move || {
                    Arc::new(
                        TcpClientBackhaul::new(None, false).add_remote_key(server_addr, server_pk),
                    )
                }),
                Protocol::DirectTls => Arc::new(move || {
                    Arc::new(
                        TcpClientBackhaul::new(None, true).add_remote_key(server_addr, server_pk),
                    )
                }),
                Protocol::ProxiedTcp(cnctr) => Arc::new(move || {
                    Arc::new(
                        TcpClientBackhaul::new(Some(cnctr.clone()), false)
                            .add_remote_key(server_addr, server_pk),
                    )
                }),
                Protocol::DirectUdp => Arc::new(move || {
                    let addr = if server_addr.is_ipv4() { "0.0.0.0:0" } else { "[::]:0" }
                        .parse::<SocketAddr>().unwrap();

                    #[cfg(not(any(target_os = "linux", target_os = "android")))]
                    let socket = runtime::new_udp_socket_bind(addr).unwrap();

                    #[cfg(any(target_os = "linux", target_os = "android"))]
                    let socket =
                        fastudp::FastUdpSocket::from(std::net::UdpSocket::bind(addr).unwrap());
                    Arc::new(socket)
                }),
            },
            num_shards: self.shard_count,
            reset_interval: self.reset_interval,
            gather: self.gather,
        })
        .await
    }
}

/// Underlying protocol for a sosistab session.
#[derive(Clone)]
pub enum Protocol {
    /// "Direct" TCP that does not go through a proxy.
    DirectTcp,
    /// "Direct" TLS.
    DirectTls,
    /// "Proxied" TCP that instead calls a function that returns a TCP connection.
    ProxiedTcp(Connector),
    /// "Direct UDP that does not go through a proxy.
    DirectUdp,
}

pub type Connector =
    Arc<dyn Fn(SocketAddr) -> Boxed<std::io::Result<TcpStream>> + Send + Sync + 'static>;

/// Connects to a remote server over UDP.
#[deprecated]
pub async fn connect_udp(
    server_addr: SocketAddr,
    pubkey: x25519_dalek::PublicKey,
    gather: Arc<StatsGatherer>,
) -> std::io::Result<Session> {
    inner::connect_custom(inner::LowlevelClientConfig {
        server_addr,
        server_pubkey: pubkey,
        backhaul_gen: Arc::new(move || {
            Arc::new(
                runtime::new_udp_socket_bind(
                    if server_addr.is_ipv4() { "0.0.0.0:0" } else { "[::]:0" }
                        .parse::<SocketAddr>().unwrap()
                ).unwrap(),
            )
        }),
        num_shards: 4,
        reset_interval: Some(Duration::from_secs(3)),
        gather,
    })
    .await
}

/// Connects to a remote server over UDP.
#[deprecated]
pub async fn connect_tcp(
    server_addr: SocketAddr,
    pubkey: x25519_dalek::PublicKey,
    gather: Arc<StatsGatherer>,
) -> std::io::Result<Session> {
    inner::connect_custom(inner::LowlevelClientConfig {
        server_addr,
        server_pubkey: pubkey,
        backhaul_gen: Arc::new(move || {
            Arc::new(TcpClientBackhaul::new(None, false).add_remote_key(server_addr, pubkey))
        }),
        num_shards: 16,
        reset_interval: None,
        gather,
    })
    .await
}