1
//! The command-line interface.
2
//!
3
//! See [`Cli`].
4

            
5
use std::ffi::OsString;
6
use std::path::PathBuf;
7

            
8
use clap::{Args, Command, Parser, Subcommand, ValueEnum};
9
use fs_mistrust::anon_home::PathExt as _;
10
use std::sync::LazyLock;
11
use tor_config::{ConfigurationSource, ConfigurationSources};
12
use tor_config_path::CfgPathError;
13

            
14
use crate::config::default_config_paths;
15

            
16
/// A cached copy of the default config paths.
17
///
18
/// We cache the values to ensure they are consistent between the help text and the values used.
19
static DEFAULT_CONFIG_PATHS: LazyLock<Result<Vec<PathBuf>, CfgPathError>> =
20
    LazyLock::new(default_config_paths);
21

            
22
/// A Rust Tor relay implementation.
23
#[derive(Clone, Debug, Parser)]
24
#[command(author = "The Tor Project Developers")]
25
#[command(version)]
26
#[command(defer = cli_cmd_post_processing)]
27
pub(crate) struct Cli {
28
    /// Sub-commands.
29
    #[command(subcommand)]
30
    pub(crate) command: Commands,
31

            
32
    /// Global arguments available for all sub-commands.
33
    ///
34
    /// These arguments may be specified before or after the subcommand argument.
35
    #[clap(flatten)]
36
    pub(crate) global: GlobalArgs,
37
}
38

            
39
/// Perform post-processing on the [`Command`] generated by clap for [`Cli`].
40
///
41
/// We use this to append the default config paths to the help text.
42
18
fn cli_cmd_post_processing(cli: Command) -> Command {
43
    /// Append the paths to the help text.
44
18
    fn fmt_help(help: Option<&str>, paths: &[PathBuf]) -> String {
45
27
        let help = help.map(|x| format!("{x}\n\n")).unwrap_or("".to_string());
46
18
        let paths: Vec<_> = paths
47
18
            .iter()
48
45
            .map(|x| x.anonymize_home().to_string())
49
18
            .collect();
50
18
        let paths = paths.join("\n");
51

            
52
        const DESC: &str =
53
            "If no paths are provided, the following config paths will be used if they exist:";
54
18
        format!("{help}{DESC}\n\n{paths}")
55
18
    }
56

            
57
    // Show the default paths in the "--help" text.
58
18
    match &*DEFAULT_CONFIG_PATHS {
59
27
        Ok(paths) => cli.mut_arg("config", |arg| {
60
18
            if let Some(help) = arg.get_long_help() {
61
                let help = help.to_string();
62
                arg.long_help(fmt_help(Some(&help), paths))
63
18
            } else if let Some(help) = arg.get_help() {
64
18
                let help = help.to_string();
65
18
                arg.long_help(fmt_help(Some(&help), paths))
66
            } else {
67
                arg.long_help(fmt_help(None, paths))
68
            }
69
27
        }),
70
        Err(_e) => cli,
71
    }
72
18
}
73

            
74
/// Main subcommands.
75
#[derive(Clone, Debug, Subcommand)]
76
pub(crate) enum Commands {
77
    /// Run the relay.
78
    Run(RunArgs),
79
    /// Print build information.
80
    BuildInfo,
81
}
82

            
83
/// Global arguments for all commands.
84
// NOTE: `global = true` should be set for each field
85
#[derive(Clone, Debug, Args)]
86
pub(crate) struct GlobalArgs {
87
    /// Override the log level from the configuration.
88
    #[arg(long, short, global = true)]
89
    #[arg(value_name = "LEVEL")]
90
    pub(crate) log_level: Option<LogLevel>,
91

            
92
    /// Don't check permissions on the files we use.
93
    #[arg(long, global = true)]
94
    pub(crate) disable_fs_permission_checks: bool,
95

            
96
    /// Override config file parameters, using TOML-like syntax.
97
    #[arg(long = "option", short, global = true)]
98
    #[arg(value_name = "KEY=VALUE")]
99
6
    pub(crate) options: Vec<String>,
100

            
101
    /// Config files and directories to read.
102
    // NOTE: We append the default config paths to the help text in `cli_cmd_post_processing`.
103
    // NOTE: This value does not take into account the default config paths,
104
    // so this is private while the `GlobalArgs::config()` method is public instead.
105
    #[arg(long, short, global = true)]
106
    #[arg(value_name = "PATH")]
107
    config: Vec<OsString>,
108
}
109

            
110
impl GlobalArgs {
111
    /// Get the configuration sources.
112
    ///
113
    /// You may also want to set a [`Mistrust`](fs_mistrust::Mistrust)
114
    /// and any additional configuration option overrides
115
    /// using [`push_option`](ConfigurationSources::push_option).
116
    pub(crate) fn config(&self) -> Result<ConfigurationSources, CfgPathError> {
117
        // Use `try_from_cmdline` to be consistent with Arti.
118
        let mut cfg_sources = ConfigurationSources::try_from_cmdline(
119
            || {
120
                Ok(DEFAULT_CONFIG_PATHS
121
                    .as_ref()
122
                    .map_err(Clone::clone)?
123
                    .iter()
124
                    .map(ConfigurationSource::from_path))
125
            },
126
            &self.config,
127
            &self.options,
128
        )?;
129

            
130
        // TODO: These text strings may become stale if the configuration structure changes,
131
        // and they're not checked at compile time.
132
        // Can we change `ConfigurationSources` in some way to allow overrides from an existing
133
        // builder?
134
        if self.disable_fs_permission_checks {
135
            cfg_sources.push_option("storage.permissions.dangerously_trust_everyone=true");
136
        }
137

            
138
        if let Some(log_level) = self.log_level {
139
            cfg_sources.push_option(format!("logging.console={log_level}"));
140
        }
141

            
142
        Ok(cfg_sources)
143
    }
144
}
145

            
146
/// Arguments when running an Arti relay.
147
#[derive(Clone, Debug, Args)]
148
pub(crate) struct RunArgs {}
149

            
150
/// Log levels allowed by the cli.
151
#[derive(Copy, Clone, Debug, Eq, PartialEq, ValueEnum)]
152
pub(crate) enum LogLevel {
153
    /// See [`tracing::Level::ERROR`].
154
    #[value(help = None)]
155
    Error,
156
    /// See [`tracing::Level::WARN`].
157
    #[value(help = None)]
158
    Warn,
159
    /// See [`tracing::Level::INFO`].
160
    #[value(help = None)]
161
    Info,
162
    /// See [`tracing::Level::DEBUG`].
163
    #[value(help = None)]
164
    Debug,
165
    /// See [`tracing::Level::TRACE`].
166
    #[value(help = None)]
167
    Trace,
168
}
169

            
170
impl std::fmt::Display for LogLevel {
171
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
172
        match self {
173
            Self::Error => write!(f, "error"),
174
            Self::Warn => write!(f, "warn"),
175
            Self::Info => write!(f, "info"),
176
            Self::Debug => write!(f, "debug"),
177
            Self::Trace => write!(f, "trace"),
178
        }
179
    }
180
}
181

            
182
impl From<LogLevel> for tracing::metadata::Level {
183
    fn from(x: LogLevel) -> Self {
184
        match x {
185
            LogLevel::Error => Self::ERROR,
186
            LogLevel::Warn => Self::WARN,
187
            LogLevel::Info => Self::INFO,
188
            LogLevel::Debug => Self::DEBUG,
189
            LogLevel::Trace => Self::TRACE,
190
        }
191
    }
192
}
193

            
194
#[cfg(test)]
195
mod test {
196
    // @@ begin test lint list maintained by maint/add_warning @@
197
    #![allow(clippy::bool_assert_comparison)]
198
    #![allow(clippy::clone_on_copy)]
199
    #![allow(clippy::dbg_macro)]
200
    #![allow(clippy::mixed_attributes_style)]
201
    #![allow(clippy::print_stderr)]
202
    #![allow(clippy::print_stdout)]
203
    #![allow(clippy::single_char_pattern)]
204
    #![allow(clippy::unwrap_used)]
205
    #![allow(clippy::unchecked_duration_subtraction)]
206
    #![allow(clippy::useless_vec)]
207
    #![allow(clippy::needless_pass_by_value)]
208
    //! <!-- @@ end test lint list maintained by maint/add_warning @@ -->
209

            
210
    use super::*;
211

            
212
    #[test]
213
    fn common_flags() {
214
        Cli::parse_from(["arti-relay", "build-info"]);
215
        Cli::parse_from(["arti-relay", "run"]);
216

            
217
        let cli = Cli::parse_from(["arti-relay", "--log-level", "warn", "run"]);
218
        assert_eq!(cli.global.log_level, Some(LogLevel::Warn));
219
        let cli = Cli::parse_from(["arti-relay", "run", "--log-level", "warn"]);
220
        assert_eq!(cli.global.log_level, Some(LogLevel::Warn));
221

            
222
        let cli = Cli::parse_from(["arti-relay", "--disable-fs-permission-checks", "run"]);
223
        assert!(cli.global.disable_fs_permission_checks);
224
        let cli = Cli::parse_from(["arti-relay", "run", "--disable-fs-permission-checks"]);
225
        assert!(cli.global.disable_fs_permission_checks);
226
    }
227

            
228
    #[test]
229
    fn clap_bug() {
230
        let cli = Cli::parse_from(["arti-relay", "-o", "foo=1", "run"]);
231
        assert_eq!(cli.global.options, vec!["foo=1"]);
232

            
233
        let cli = Cli::parse_from(["arti-relay", "-o", "foo=1", "-o", "bar=2", "run"]);
234
        assert_eq!(cli.global.options, vec!["foo=1", "bar=2"]);
235

            
236
        // this is https://github.com/clap-rs/clap/issues/3938
237
        // TODO: this is a footgun, and we should consider alternatives to clap's 'global' args
238
        let cli = Cli::parse_from(["arti-relay", "-o", "foo=1", "run", "-o", "bar=2"]);
239
        assert_eq!(cli.global.options, vec!["bar=2"]);
240
    }
241

            
242
    #[test]
243
    fn global_args_are_global() {
244
        let cmd = Command::new("test");
245
        let cmd = GlobalArgs::augment_args(cmd);
246

            
247
        // check that each argument in `GlobalArgs` has "global" set
248
        for arg in cmd.get_arguments() {
249
            assert!(
250
                arg.is_global_set(),
251
                "'global' must be set for {:?}",
252
                arg.get_long()
253
            );
254
        }
255
    }
256
}