gix_transport/client/blocking_io/ssh/
program_kind.rs

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
use std::{ffi::OsStr, io::ErrorKind};

use bstr::{BString, ByteSlice, ByteVec};

use gix_url::ArgumentSafety::*;

use crate::{
    client::{ssh, ssh::ProgramKind},
    Protocol,
};

impl ProgramKind {
    /// Provide the name of the executable that belongs to this kind, or `None` if the kind is `Simple`.
    pub fn exe(&self) -> Option<&'static OsStr> {
        Some(OsStr::new(match self {
            ProgramKind::Ssh => "ssh",
            ProgramKind::Plink => "plink",
            ProgramKind::Putty => "putty",
            ProgramKind::TortoisePlink => "tortoiseplink.exe",
            ProgramKind::Simple => return None,
        }))
    }

    /// Prepare all information needed to invoke the ssh command
    pub(crate) fn prepare_invocation(
        &self,
        ssh_cmd: &OsStr,
        url: &gix_url::Url,
        desired_version: Protocol,
        disallow_shell: bool,
    ) -> Result<gix_command::Prepare, ssh::invocation::Error> {
        let mut prepare = gix_command::prepare(ssh_cmd).with_shell();
        if disallow_shell {
            prepare.use_shell = false;
        }
        match self {
            ProgramKind::Ssh => {
                if desired_version != Protocol::V1 {
                    prepare = prepare
                        .args(["-o", "SendEnv=GIT_PROTOCOL"])
                        .env("GIT_PROTOCOL", format!("version={}", desired_version as usize));
                }
                if let Some(port) = url.port {
                    prepare = prepare.arg(format!("-p{port}"));
                }
            }
            ProgramKind::Plink | ProgramKind::Putty | ProgramKind::TortoisePlink => {
                if *self == ProgramKind::TortoisePlink {
                    prepare = prepare.arg("-batch");
                }
                if let Some(port) = url.port {
                    prepare = prepare.arg("-P");
                    prepare = prepare.arg(port.to_string());
                }
            }
            ProgramKind::Simple => {
                if url.port.is_some() {
                    return Err(ssh::invocation::Error::Unsupported {
                        command: ssh_cmd.into(),
                        function: "setting the port",
                    });
                }
            }
        };

        let host_maybe_with_user_as_ssh_arg = match (url.user_as_argument(), url.host_as_argument()) {
            (Usable(user), Usable(host)) => format!("{user}@{host}"),
            (Usable(user), Dangerous(host)) => format!("{user}@{host}"), // The `user@` makes it safe.
            (Absent, Usable(host)) => host.into(),
            (Dangerous(user), _) => Err(ssh::invocation::Error::AmbiguousUserName { user: user.into() })?,
            (_, Dangerous(host)) => Err(ssh::invocation::Error::AmbiguousHostName { host: host.into() })?,
            (_, Absent) => panic!("BUG: host should always be present in SSH URLs"),
        };

        Ok(prepare
            .arg(host_maybe_with_user_as_ssh_arg)
            // Try to force ssh to yield English messages (for parsing later).
            .env("LANG", "C")
            .env("LC_ALL", "C"))
    }

    /// Note that the caller has to assure that the ssh program is launched in English by setting the locale.
    pub(crate) fn line_to_err(&self, line: BString) -> Result<std::io::Error, BString> {
        let kind = match self {
            ProgramKind::Ssh | ProgramKind::Simple => {
                if line.contains_str(b"Permission denied") || line.contains_str(b"permission denied") {
                    Some(ErrorKind::PermissionDenied)
                } else if line.contains_str(b"resolve hostname") {
                    Some(ErrorKind::ConnectionRefused)
                } else if line.contains_str(b"connect to host")
                    || line.contains_str("Connection to ")
                    || line.contains_str("Connection closed by ")
                {
                    // TODO: turn this into HostUnreachable when stable, or NetworkUnreachable in 'no route' example.
                    //       It's important that it WON'T be considered spurious, but is considered a permanent failure.
                    Some(ErrorKind::NotFound)
                } else {
                    None
                }
            }
            ProgramKind::Plink | ProgramKind::Putty | ProgramKind::TortoisePlink => {
                if line.contains_str(b"publickey") {
                    Some(ErrorKind::PermissionDenied)
                } else {
                    None
                }
            }
        };
        match kind {
            Some(kind) => Ok(std::io::Error::new(kind, Vec::from(line).into_string_lossy())),
            None => Err(line),
        }
    }
}

impl<'a> From<&'a OsStr> for ProgramKind {
    fn from(v: &'a OsStr) -> Self {
        let p = std::path::Path::new(v);
        match p.file_stem().and_then(OsStr::to_str) {
            None => ProgramKind::Simple,
            Some(stem) => {
                if stem.eq_ignore_ascii_case("ssh") {
                    ProgramKind::Ssh
                } else if stem.eq_ignore_ascii_case("plink") {
                    ProgramKind::Plink
                } else if stem.eq_ignore_ascii_case("putty") {
                    ProgramKind::Putty
                } else if stem.eq_ignore_ascii_case("tortoiseplink") {
                    ProgramKind::TortoisePlink
                } else {
                    ProgramKind::Simple
                }
            }
        }
    }
}