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 once_cell::sync::Lazy;
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: Lazy<Result<Vec<PathBuf>, CfgPathError>> =
20
    Lazy::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
        /// TODO MSRV 1.84: remove this comment
53
        /// https://github.com/rust-lang/rust-clippy/issues/13802
54
        const DESC: &str =
55
            "If no paths are provided, the following config paths will be used if they exist:";
56
18
        format!("{help}{DESC}\n\n{paths}")
57
18
    }
58

            
59
    // Show the default paths in the "--help" text.
60
18
    match &*DEFAULT_CONFIG_PATHS {
61
27
        Ok(paths) => cli.mut_arg("config", |arg| {
62
18
            if let Some(help) = arg.get_long_help() {
63
                let help = help.to_string();
64
                arg.long_help(fmt_help(Some(&help), paths))
65
18
            } else if let Some(help) = arg.get_help() {
66
18
                let help = help.to_string();
67
18
                arg.long_help(fmt_help(Some(&help), paths))
68
            } else {
69
                arg.long_help(fmt_help(None, paths))
70
            }
71
27
        }),
72
        Err(_e) => cli,
73
    }
74
18
}
75

            
76
/// Main subcommands.
77
#[derive(Clone, Debug, Subcommand)]
78
pub(crate) enum Commands {
79
    /// Run the relay.
80
    Run(RunArgs),
81
    /// Print build information.
82
    BuildInfo,
83
}
84

            
85
/// Global arguments for all commands.
86
// NOTE: `global = true` should be set for each field
87
#[derive(Clone, Debug, Args)]
88
pub(crate) struct GlobalArgs {
89
    /// Override the log level from the configuration.
90
    #[arg(long, short, global = true)]
91
    #[arg(value_name = "LEVEL")]
92
    pub(crate) log_level: Option<LogLevel>,
93

            
94
    /// Don't check permissions on the files we use.
95
    #[arg(long, global = true)]
96
    pub(crate) disable_fs_permission_checks: bool,
97

            
98
    /// Override config file parameters, using TOML-like syntax.
99
    #[arg(long = "option", short, global = true)]
100
    #[arg(value_name = "KEY=VALUE")]
101
6
    pub(crate) options: Vec<String>,
102

            
103
    /// Config files and directories to read.
104
    // NOTE: We append the default config paths to the help text in `cli_cmd_post_processing`.
105
    // NOTE: This value does not take into account the default config paths,
106
    // so this is private while the `GlobalArgs::config()` method is public instead.
107
    #[arg(long, short, global = true)]
108
    #[arg(value_name = "PATH")]
109
    config: Vec<OsString>,
110
}
111

            
112
impl GlobalArgs {
113
    /// Get the configuration sources.
114
    ///
115
    /// You may also want to set a [`Mistrust`](fs_mistrust::Mistrust)
116
    /// and any additional configuration option overrides
117
    /// using [`push_option`](ConfigurationSources::push_option).
118
    pub(crate) fn config(&self) -> Result<ConfigurationSources, CfgPathError> {
119
        // Use `try_from_cmdline` to be consistent with Arti.
120
        let mut cfg_sources = ConfigurationSources::try_from_cmdline(
121
            || {
122
                Ok(DEFAULT_CONFIG_PATHS
123
                    .as_ref()
124
                    .map_err(Clone::clone)?
125
                    .iter()
126
                    .map(ConfigurationSource::from_path))
127
            },
128
            &self.config,
129
            &self.options,
130
        )?;
131

            
132
        // TODO: These text strings may become stale if the configuration structure changes,
133
        // and they're not checked at compile time.
134
        // Can we change `ConfigurationSources` in some way to allow overrides from an existing
135
        // builder?
136
        if self.disable_fs_permission_checks {
137
            cfg_sources.push_option("storage.permissions.dangerously_trust_everyone=true");
138
        }
139

            
140
        if let Some(log_level) = self.log_level {
141
            cfg_sources.push_option(format!("logging.console={log_level}"));
142
        }
143

            
144
        Ok(cfg_sources)
145
    }
146
}
147

            
148
/// Arguments when running an Arti relay.
149
#[derive(Clone, Debug, Args)]
150
pub(crate) struct RunArgs {}
151

            
152
/// Log levels allowed by the cli.
153
#[derive(Copy, Clone, Debug, Eq, PartialEq, ValueEnum)]
154
pub(crate) enum LogLevel {
155
    /// See [`tracing::Level::ERROR`].
156
    #[value(help = None)]
157
    Error,
158
    /// See [`tracing::Level::WARN`].
159
    #[value(help = None)]
160
    Warn,
161
    /// See [`tracing::Level::INFO`].
162
    #[value(help = None)]
163
    Info,
164
    /// See [`tracing::Level::DEBUG`].
165
    #[value(help = None)]
166
    Debug,
167
    /// See [`tracing::Level::TRACE`].
168
    #[value(help = None)]
169
    Trace,
170
}
171

            
172
impl std::fmt::Display for LogLevel {
173
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
174
        match self {
175
            Self::Error => write!(f, "error"),
176
            Self::Warn => write!(f, "warn"),
177
            Self::Info => write!(f, "info"),
178
            Self::Debug => write!(f, "debug"),
179
            Self::Trace => write!(f, "trace"),
180
        }
181
    }
182
}
183

            
184
impl From<LogLevel> for tracing::metadata::Level {
185
    fn from(x: LogLevel) -> Self {
186
        match x {
187
            LogLevel::Error => Self::ERROR,
188
            LogLevel::Warn => Self::WARN,
189
            LogLevel::Info => Self::INFO,
190
            LogLevel::Debug => Self::DEBUG,
191
            LogLevel::Trace => Self::TRACE,
192
        }
193
    }
194
}
195

            
196
#[cfg(test)]
197
mod test {
198
    // @@ begin test lint list maintained by maint/add_warning @@
199
    #![allow(clippy::bool_assert_comparison)]
200
    #![allow(clippy::clone_on_copy)]
201
    #![allow(clippy::dbg_macro)]
202
    #![allow(clippy::mixed_attributes_style)]
203
    #![allow(clippy::print_stderr)]
204
    #![allow(clippy::print_stdout)]
205
    #![allow(clippy::single_char_pattern)]
206
    #![allow(clippy::unwrap_used)]
207
    #![allow(clippy::unchecked_duration_subtraction)]
208
    #![allow(clippy::useless_vec)]
209
    #![allow(clippy::needless_pass_by_value)]
210
    //! <!-- @@ end test lint list maintained by maint/add_warning @@ -->
211

            
212
    use super::*;
213

            
214
    #[test]
215
    fn common_flags() {
216
        Cli::parse_from(["arti-relay", "build-info"]);
217
        Cli::parse_from(["arti-relay", "run"]);
218

            
219
        let cli = Cli::parse_from(["arti-relay", "--log-level", "warn", "run"]);
220
        assert_eq!(cli.global.log_level, Some(LogLevel::Warn));
221
        let cli = Cli::parse_from(["arti-relay", "run", "--log-level", "warn"]);
222
        assert_eq!(cli.global.log_level, Some(LogLevel::Warn));
223

            
224
        let cli = Cli::parse_from(["arti-relay", "--disable-fs-permission-checks", "run"]);
225
        assert!(cli.global.disable_fs_permission_checks);
226
        let cli = Cli::parse_from(["arti-relay", "run", "--disable-fs-permission-checks"]);
227
        assert!(cli.global.disable_fs_permission_checks);
228
    }
229

            
230
    #[test]
231
    fn clap_bug() {
232
        let cli = Cli::parse_from(["arti-relay", "-o", "foo=1", "run"]);
233
        assert_eq!(cli.global.options, vec!["foo=1"]);
234

            
235
        let cli = Cli::parse_from(["arti-relay", "-o", "foo=1", "-o", "bar=2", "run"]);
236
        assert_eq!(cli.global.options, vec!["foo=1", "bar=2"]);
237

            
238
        // this is https://github.com/clap-rs/clap/issues/3938
239
        // TODO: this is a footgun, and we should consider alternatives to clap's 'global' args
240
        let cli = Cli::parse_from(["arti-relay", "-o", "foo=1", "run", "-o", "bar=2"]);
241
        assert_eq!(cli.global.options, vec!["bar=2"]);
242
    }
243

            
244
    #[test]
245
    fn global_args_are_global() {
246
        let cmd = Command::new("test");
247
        let cmd = GlobalArgs::augment_args(cmd);
248

            
249
        // check that each argument in `GlobalArgs` has "global" set
250
        for arg in cmd.get_arguments() {
251
            assert!(
252
                arg.is_global_set(),
253
                "'global' must be set for {:?}",
254
                arg.get_long()
255
            );
256
        }
257
    }
258
}