rneter 0.4.3

SSH connection manager for network devices with intelligent state machine handling
Documentation 
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
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251

use log::trace;

use super::{
    DeviceHandler, STRIP_CSI_ESCAPE, STRIP_DCS_ESCAPE, STRIP_OSC_ESCAPE, STRIP_SIMPLE_ESCAPE,
};

fn sanitize_terminal_line(line: &str) -> String {
    let without_osc = STRIP_OSC_ESCAPE.replace_all(line, "");
    let without_dcs = STRIP_DCS_ESCAPE.replace_all(without_osc.as_ref(), "");
    let without_csi = STRIP_CSI_ESCAPE.replace_all(without_dcs.as_ref(), "");
    let without_simple = STRIP_SIMPLE_ESCAPE.replace_all(without_csi.as_ref(), "");
    without_simple
        .chars()
        .filter(|ch| !ch.is_control() || matches!(ch, '\n' | '\r' | '\t'))
        .collect()
}

fn latest_terminal_fragment(line: &str) -> &str {
    line.rsplit(['\n', '\r'])
        .find(|segment| !segment.is_empty())
        .unwrap_or(line)
}

impl DeviceHandler {
    /// Converts a line of output to a state.
    ///
    /// Matches the line against all known regex patterns and returns the corresponding state.
    /// If no match is found, defaults to the "Output" state.
    fn line2state(&self, line: &str, need_catch: bool) -> (usize, &str, Option<String>) {
        let matches: Vec<_> = self.all_regex.matches(line).into_iter().collect();
        if matches.is_empty() {
            let state = self
                .all_states
                .first()
                .map(|s| s.as_str())
                .unwrap_or("output");
            return (0, state, None);
        }
        let mut current_state_catch = None;
        let index = match matches.first() {
            Some(v) => *v,
            None => {
                let state = self
                    .all_states
                    .first()
                    .map(|s| s.as_str())
                    .unwrap_or("output");
                return (0, state, None);
            }
        };
        if need_catch
            && let Some((regex, catch)) = self.catch_map.get(&index)
            && let Some(caps) = regex.captures(line)
        {
            current_state_catch = caps.name(catch).map(|s| s.as_str().to_string());
        }
        let state_index = self.regex_index_map.get(&index).copied().unwrap_or(0);
        let state = self
            .all_states
            .get(state_index)
            .map(|s| s.as_str())
            .unwrap_or("output");
        (state_index, state, current_state_catch)
    }

    /// Reads a line of output and updates the current state.
    pub fn read(&mut self, line: &str) {
        let sanitized_line = sanitize_terminal_line(line);
        let prompt_line = latest_terminal_fragment(&sanitized_line);
        trace!("Read line: '{:?}'", prompt_line);
        let (state_index, state, catch) = self.line2state(prompt_line, true);
        trace!("Converted to state: '{:?}'", state);
        if self.ignore_error(prompt_line) {
            trace!("Ignoring error state");
            self.current_state_index = 0;
        } else {
            if self.match_prompt(state_index) {
                trace!("State captured value: '{:?}'", catch);
                self.sys = catch;
                self.current_prompt = Some(prompt_line.to_string());
            }

            self.current_state_index = state_index;
        }
    }

    fn ignore_error(&self, line: &str) -> bool {
        self.ignore_errors
            .as_ref()
            .map(|set| set.is_match(line))
            .unwrap_or(false)
    }

    fn match_prompt(&self, index: usize) -> bool {
        let (start, end) = self.prompt_index;
        index >= start && index <= end
    }

    pub(super) fn match_sys_prompt(&self, index: usize) -> bool {
        let (start, end) = self.sys_prompt_index;
        index >= start && index <= end
    }

    /// Checks if a line matches a prompt pattern.
    pub fn read_prompt(&mut self, line: &str) -> bool {
        let sanitized_line = sanitize_terminal_line(line);
        let prompt_line = latest_terminal_fragment(&sanitized_line);
        trace!("Checking if line is a prompt: '{:?}'", prompt_line);
        let (index, _, _) = self.line2state(prompt_line, false);
        self.match_prompt(index)
    }

    /// Checks if a line matches a system-specific prompt pattern.
    pub fn read_sys_prompt(&mut self, line: &str) -> bool {
        let sanitized_line = sanitize_terminal_line(line);
        let prompt_line = latest_terminal_fragment(&sanitized_line);
        trace!("Checking if line is a system prompt: '{:?}'", prompt_line);
        let (index, _, _) = self.line2state(prompt_line, false);
        self.match_sys_prompt(index)
    }

    /// Checks if a line requires input and returns the input to send.
    pub fn read_need_write(&mut self, line: &str) -> Option<(String, bool)> {
        let sanitized_line = sanitize_terminal_line(line);
        let prompt_line = latest_terminal_fragment(&sanitized_line);
        trace!("Checking if input is required: '{:?}'", prompt_line);
        let (_, input, _) = self.line2state(prompt_line, false);
        if let Some((is_dyn, s, is_record)) = self.input_map.get(input) {
            if *is_dyn {
                return self.dyn_param.get(s).map(|cmd| (cmd.clone(), *is_record));
            }
            return Some((s.clone(), *is_record));
        }
        None
    }

    /// Returns the current state name.
    pub fn current_state(&self) -> &str {
        self.all_states
            .get(self.current_state_index)
            .map(|s| s.as_str())
            .unwrap_or("output")
    }

    /// Returns the currently captured system name, if available.
    pub fn current_sys(&self) -> Option<&str> {
        self.sys.as_deref()
    }

    /// Returns last prompt text matched by the state machine.
    pub fn current_prompt(&self) -> Option<&str> {
        self.current_prompt.as_deref()
    }

    /// Returns all declared state names.
    pub fn states(&self) -> Vec<String> {
        self.all_states.clone()
    }

    /// Returns all configured transition edges.
    pub fn edges(&self) -> Vec<(String, String, String, bool, bool)> {
        self.edges.clone()
    }

    /// Checks if the current state is an error state.
    pub fn error(&self) -> bool {
        self.current_state().eq("error")
    }
}

#[cfg(test)]
mod tests {
    use super::super::build_test_handler;
    use crate::templates;

    #[test]
    fn error_state_is_detected_after_error_line() {
        let mut handler = build_test_handler();

        assert!(!handler.error());
        handler.read("ERROR: invalid command");
        assert!(handler.error());
    }

    #[test]
    fn ignore_error_pattern_resets_to_output_state() {
        let mut handler = build_test_handler();

        handler.read("ERROR: benign");
        assert_eq!(handler.current_state(), "output");
        assert!(!handler.error());
    }

    #[test]
    fn current_prompt_is_updated_when_prompt_line_is_read() {
        let mut handler = build_test_handler();
        assert_eq!(handler.current_prompt(), None);

        handler.read("dev#");
        assert_eq!(handler.current_prompt(), Some("dev#"));
    }

    #[test]
    fn read_need_write_supports_dynamic_and_static_inputs() {
        let mut handler = build_test_handler();

        assert_eq!(
            handler.read_need_write("Password:"),
            Some(("secret\n".to_string(), true))
        );
        assert_eq!(
            handler.read_need_write("[y/n]?"),
            Some(("y".to_string(), false))
        );
        assert_eq!(handler.read_need_write("no input"), None);
    }

    #[test]
    fn linux_prompt_matches_after_stripping_ansi_sequences() {
        let mut handler = templates::linux().expect("create linux template");
        let raw_prompt = "\u{1b}]0;root@test-65:~\u{7}\u{1b}[?1034h[root@test-65 ~]# ";

        assert!(handler.read_prompt(raw_prompt));
        handler.read(raw_prompt);
        assert_eq!(handler.current_state(), "root");
        assert_eq!(handler.current_prompt(), Some("[root@test-65 ~]# "));
    }

    #[test]
    fn fish_prompt_matches_after_stripping_terminal_probe_sequences() {
        let mut handler = templates::linux().expect("create linux template");
        let raw_prompt = "\u{1b}[?u\u{1b}[>0q\u{1b}[?1049h\u{1b}P+q696e646e\u{1b}\\\u{1b}[?1049l\u{1b}[0c\u{1b}]133;A;click_events=1\u{7}\u{1b}[92mroot\u{1b}[m@\u{1b}[33m192-168-30-92\u{1b}[m \u{1b}[31m~\u{1b}[m# ";

        assert!(handler.read_prompt(raw_prompt));
        handler.read(raw_prompt);
        assert_eq!(handler.current_state(), "root");
        assert_eq!(handler.current_prompt(), Some("root@192-168-30-92 ~# "));
    }

    #[test]
    fn fish_prompt_matches_last_carriage_return_fragment() {
        let mut handler = templates::linux().expect("create linux template");
        let raw_prompt =
            "noise-before\r\u{1b}>\u{1b}[92m[192-168-30]\u{1b}[m \u{1b}[31m~\u{1b}[m# ";

        assert!(handler.read_prompt(raw_prompt));
        handler.read(raw_prompt);
        assert_eq!(handler.current_state(), "root");
        assert_eq!(handler.current_prompt(), Some("[192-168-30] ~# "));
    }
}