runner/
lib.rs

1// Copyright 2019 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5pub mod component;
6pub mod serde;
7
8use fidl::endpoints::ServerEnd;
9#[cfg(fuchsia_api_level_at_least = "HEAD")]
10use fidl_fuchsia_component_sandbox as fsandbox;
11#[cfg(fuchsia_api_level_at_least = "23")]
12use fidl_fuchsia_component_sandbox as _;
13use std::path::Path;
14use thiserror::Error;
15use {
16    fidl_fuchsia_component_runner as fcrunner, fidl_fuchsia_data as fdata, fidl_fuchsia_io as fio,
17    fidl_fuchsia_mem as fmem, fidl_fuchsia_process as fprocess,
18};
19
20const ARGS_KEY: &str = "args";
21const BINARY_KEY: &str = "binary";
22const ENVIRON_KEY: &str = "environ";
23
24/// An error encountered trying to get entry out of `ComponentStartInfo->program`.
25#[derive(Clone, Debug, PartialEq, Eq, Error)]
26pub enum StartInfoProgramError {
27    #[error("\"program.binary\" must be specified")]
28    MissingBinary,
29
30    #[error("the value of \"program.binary\" must be a string")]
31    InValidBinaryType,
32
33    #[error("the value of \"program.binary\" must be a relative path")]
34    BinaryPathNotRelative,
35
36    #[error("the value of \"program.{0}\" must be an array of strings")]
37    InvalidStrVec(String),
38
39    #[error("\"program\" must be specified")]
40    NotFound,
41
42    #[error("invalid type for key \"{0}\", expected string")]
43    InvalidType(String),
44
45    #[error("invalid value for key \"{0}\", expected one of \"{1}\", found \"{2}\"")]
46    InvalidValue(String, String, String),
47
48    #[error("environ value at index \"{0}\" is invalid. Value must be format of 'VARIABLE=VALUE'")]
49    InvalidEnvironValue(usize),
50}
51
52/// Retrieves component URL from start_info or errors out if not found.
53pub fn get_resolved_url(start_info: &fcrunner::ComponentStartInfo) -> Option<String> {
54    start_info.resolved_url.clone()
55}
56
57/// Returns a reference to the value corresponding to the key.
58pub fn get_value<'a>(dict: &'a fdata::Dictionary, key: &str) -> Option<&'a fdata::DictionaryValue> {
59    match &dict.entries {
60        Some(entries) => {
61            for entry in entries {
62                if entry.key == key {
63                    return entry.value.as_ref().map(|val| &**val);
64                }
65            }
66            None
67        }
68        _ => None,
69    }
70}
71
72/// Retrieve a reference to the enum value corresponding to the key.
73pub fn get_enum<'a>(
74    dict: &'a fdata::Dictionary,
75    key: &str,
76    variants: &[&str],
77) -> Result<Option<&'a str>, StartInfoProgramError> {
78    match get_value(dict, key) {
79        Some(fdata::DictionaryValue::Str(value)) => {
80            if variants.contains(&value.as_str()) {
81                Ok(Some(value.as_ref()))
82            } else {
83                Err(StartInfoProgramError::InvalidValue(
84                    key.to_owned(),
85                    format!("{:?}", variants),
86                    value.to_owned(),
87                ))
88            }
89        }
90        Some(_) => Err(StartInfoProgramError::InvalidType(key.to_owned())),
91        None => Ok(None),
92    }
93}
94
95/// Retrieve value of type bool. Defaults to 'false' if key is not found.
96pub fn get_bool<'a>(dict: &'a fdata::Dictionary, key: &str) -> Result<bool, StartInfoProgramError> {
97    match get_enum(dict, key, &["true", "false"])? {
98        Some("true") => Ok(true),
99        _ => Ok(false),
100    }
101}
102
103fn get_program_value<'a>(
104    start_info: &'a fcrunner::ComponentStartInfo,
105    key: &str,
106) -> Option<&'a fdata::DictionaryValue> {
107    get_value(start_info.program.as_ref()?, key)
108}
109
110/// Retrieve a string from the program dictionary in ComponentStartInfo.
111pub fn get_program_string<'a>(
112    start_info: &'a fcrunner::ComponentStartInfo,
113    key: &str,
114) -> Option<&'a str> {
115    if let fdata::DictionaryValue::Str(value) = get_program_value(start_info, key)? {
116        Some(value)
117    } else {
118        None
119    }
120}
121
122/// Retrieve a StrVec from the program dictionary in ComponentStartInfo. Returns StartInfoProgramError::InvalidStrVec if
123/// the value is not a StrVec.
124pub fn get_program_strvec<'a>(
125    start_info: &'a fcrunner::ComponentStartInfo,
126    key: &str,
127) -> Result<Option<&'a Vec<String>>, StartInfoProgramError> {
128    match get_program_value(start_info, key) {
129        Some(args_value) => match args_value {
130            fdata::DictionaryValue::StrVec(vec) => Ok(Some(vec)),
131            _ => Err(StartInfoProgramError::InvalidStrVec(key.to_string())),
132        },
133        None => Ok(None),
134    }
135}
136
137/// Retrieves program.binary from ComponentStartInfo and makes sure that path is relative.
138// TODO(https://fxbug.dev/42079981): This method should accept a program dict instead of start_info
139pub fn get_program_binary(
140    start_info: &fcrunner::ComponentStartInfo,
141) -> Result<String, StartInfoProgramError> {
142    if let Some(program) = &start_info.program {
143        get_program_binary_from_dict(&program)
144    } else {
145        Err(StartInfoProgramError::NotFound)
146    }
147}
148
149/// Retrieves `binary` from a ComponentStartInfo dict and makes sure that path is relative.
150pub fn get_program_binary_from_dict(
151    dict: &fdata::Dictionary,
152) -> Result<String, StartInfoProgramError> {
153    if let Some(val) = get_value(&dict, BINARY_KEY) {
154        if let fdata::DictionaryValue::Str(bin) = val {
155            if !Path::new(bin).is_absolute() {
156                Ok(bin.to_string())
157            } else {
158                Err(StartInfoProgramError::BinaryPathNotRelative)
159            }
160        } else {
161            Err(StartInfoProgramError::InValidBinaryType)
162        }
163    } else {
164        Err(StartInfoProgramError::MissingBinary)
165    }
166}
167
168/// Retrieves program.args from ComponentStartInfo and validates them.
169// TODO(https://fxbug.dev/42079981): This method should accept a program dict instead of start_info
170pub fn get_program_args(
171    start_info: &fcrunner::ComponentStartInfo,
172) -> Result<Vec<String>, StartInfoProgramError> {
173    match get_program_strvec(start_info, ARGS_KEY)? {
174        Some(vec) => Ok(vec.iter().map(|v| v.clone()).collect()),
175        None => Ok(vec![]),
176    }
177}
178
179/// Retrieves `args` from a ComponentStartInfo program dict and validates them.
180pub fn get_program_args_from_dict(
181    dict: &fdata::Dictionary,
182) -> Result<Vec<String>, StartInfoProgramError> {
183    match get_value(&dict, ARGS_KEY) {
184        Some(args_value) => match args_value {
185            fdata::DictionaryValue::StrVec(vec) => Ok(vec.iter().map(|v| v.clone()).collect()),
186            _ => Err(StartInfoProgramError::InvalidStrVec(ARGS_KEY.to_string())),
187        },
188        None => Ok(vec![]),
189    }
190}
191
192pub fn get_environ(dict: &fdata::Dictionary) -> Result<Option<Vec<String>>, StartInfoProgramError> {
193    // Temporarily allow unreachable patterns while fuchsia.data.DictionaryValue
194    // is migrated from `strict` to `flexible`.
195    // TODO(https://fxbug.dev/42173900): Remove this.
196    #[allow(unreachable_patterns)]
197    match get_value(dict, ENVIRON_KEY) {
198        Some(fdata::DictionaryValue::StrVec(values)) => {
199            if values.is_empty() {
200                return Ok(None);
201            }
202            for (i, value) in values.iter().enumerate() {
203                let parts = value.split_once("=");
204                if parts.is_none() {
205                    return Err(StartInfoProgramError::InvalidEnvironValue(i));
206                }
207                let parts = parts.unwrap();
208                // The value of an environment variable can in fact be empty.
209                if parts.0.is_empty() {
210                    return Err(StartInfoProgramError::InvalidEnvironValue(i));
211                }
212            }
213            Ok(Some(values.clone()))
214        }
215        Some(fdata::DictionaryValue::Str(_)) => Err(StartInfoProgramError::InvalidValue(
216            ENVIRON_KEY.to_owned(),
217            "vector of string".to_owned(),
218            "string".to_owned(),
219        )),
220        Some(other) => Err(StartInfoProgramError::InvalidValue(
221            ENVIRON_KEY.to_owned(),
222            "vector of string".to_owned(),
223            format!("{:?}", other),
224        )),
225        None => Ok(None),
226    }
227}
228
229/// Errors from parsing a component's configuration data.
230#[derive(Debug, Clone, Error)]
231pub enum ConfigDataError {
232    #[error("failed to create a vmo: {_0}")]
233    VmoCreate(#[source] zx::Status),
234    #[error("failed to write to vmo: {_0}")]
235    VmoWrite(#[source] zx::Status),
236    #[error("encountered an unrecognized variant of fuchsia.mem.Data")]
237    UnrecognizedDataVariant,
238}
239
240pub fn get_config_vmo(encoded_config: fmem::Data) -> Result<zx::Vmo, ConfigDataError> {
241    match encoded_config {
242        fmem::Data::Buffer(fmem::Buffer {
243            vmo,
244            size: _, // we get this vmo from component manager which sets the content size
245        }) => Ok(vmo),
246        fmem::Data::Bytes(bytes) => {
247            let size = bytes.len() as u64;
248            let vmo = zx::Vmo::create(size).map_err(ConfigDataError::VmoCreate)?;
249            vmo.write(&bytes, 0).map_err(ConfigDataError::VmoWrite)?;
250            Ok(vmo)
251        }
252        _ => Err(ConfigDataError::UnrecognizedDataVariant.into()),
253    }
254}
255
256/// Errors from parsing ComponentStartInfo.
257#[derive(Debug, Clone, Error)]
258pub enum StartInfoError {
259    #[error("missing program")]
260    MissingProgram,
261    #[error("missing resolved URL")]
262    MissingResolvedUrl,
263}
264
265impl StartInfoError {
266    /// Convert this error into its approximate `zx::Status` equivalent.
267    pub fn as_zx_status(&self) -> zx::Status {
268        match self {
269            StartInfoError::MissingProgram => zx::Status::INVALID_ARGS,
270            StartInfoError::MissingResolvedUrl => zx::Status::INVALID_ARGS,
271        }
272    }
273}
274
275/// [StartInfo] is convertible from the FIDL [fcrunner::ComponentStartInfo]
276/// type and performs validation that makes sense for all runners in the process.
277pub struct StartInfo {
278    /// The resolved URL of the component.
279    ///
280    /// This is the canonical URL obtained by the component resolver after
281    /// following redirects and resolving relative paths.
282    pub resolved_url: String,
283
284    /// The component's program declaration.
285    /// This information originates from `ComponentDecl.program`.
286    pub program: fdata::Dictionary,
287
288    /// The namespace to provide to the component instance.
289    ///
290    /// A namespace specifies the set of directories that a component instance
291    /// receives at start-up. Through the namespace directories, a component
292    /// may access capabilities available to it. The contents of the namespace
293    /// are mainly determined by the component's `use` declarations but may
294    /// also contain additional capabilities automatically provided by the
295    /// framework.
296    ///
297    /// By convention, a component's namespace typically contains some or all
298    /// of the following directories:
299    ///
300    /// - "/svc": A directory containing services that the component requested
301    ///           to use via its "import" declarations.
302    /// - "/pkg": A directory containing the component's package, including its
303    ///           binaries, libraries, and other assets.
304    ///
305    /// The mount points specified in each entry must be unique and
306    /// non-overlapping. For example, [{"/foo", ..}, {"/foo/bar", ..}] is
307    /// invalid.
308    pub namespace: Vec<fcrunner::ComponentNamespaceEntry>,
309
310    /// The directory this component serves.
311    pub outgoing_dir: Option<ServerEnd<fio::DirectoryMarker>>,
312
313    /// The directory served by the runner to present runtime information about
314    /// the component. The runner must either serve it, or drop it to avoid
315    /// blocking any consumers indefinitely.
316    pub runtime_dir: Option<ServerEnd<fio::DirectoryMarker>>,
317
318    /// The numbered handles that were passed to the component.
319    ///
320    /// If the component does not support numbered handles, the runner is expected
321    /// to close the handles.
322    pub numbered_handles: Vec<fprocess::HandleInfo>,
323
324    /// Binary representation of the component's configuration.
325    ///
326    /// # Layout
327    ///
328    /// The first 2 bytes of the data should be interpreted as an unsigned 16-bit
329    /// little-endian integer which denotes the number of bytes following it that
330    /// contain the configuration checksum. After the checksum, all the remaining
331    /// bytes are a persistent FIDL message of a top-level struct. The struct's
332    /// fields match the configuration fields of the component's compiled manifest
333    /// in the same order.
334    pub encoded_config: Option<fmem::Data>,
335
336    /// An eventpair that debuggers can use to defer the launch of the component.
337    ///
338    /// For example, ELF runners hold off from creating processes in the component
339    /// until ZX_EVENTPAIR_PEER_CLOSED is signaled on this eventpair. They also
340    /// ensure that runtime_dir is served before waiting on this eventpair.
341    /// ELF debuggers can query the runtime_dir to decide whether to attach before
342    /// they drop the other side of the eventpair, which is sent in the payload of
343    /// the DebugStarted event in fuchsia.component.events.
344    pub break_on_start: Option<zx::EventPair>,
345
346    /// An opaque token that represents the component instance.
347    ///
348    /// The `fuchsia.component/Introspector` protocol may be used to get the
349    /// string moniker of the instance from this token.
350    ///
351    /// Runners may publish this token as part of diagnostics information, to
352    /// identify the running component without knowing its moniker.
353    ///
354    /// The token is invalidated when the component instance is destroyed.
355    #[cfg(fuchsia_api_level_at_least = "HEAD")]
356    pub component_instance: Option<zx::Event>,
357
358    /// A dictionary containing data and handles that the component has escrowed
359    /// during its previous execution via
360    /// `fuchsia.component.runner/ComponentController.OnEscrow`.
361    #[cfg(fuchsia_api_level_at_least = "HEAD")]
362    pub escrowed_dictionary: Option<fsandbox::DictionaryRef>,
363}
364
365impl TryFrom<fcrunner::ComponentStartInfo> for StartInfo {
366    type Error = StartInfoError;
367    fn try_from(start_info: fcrunner::ComponentStartInfo) -> Result<Self, Self::Error> {
368        let resolved_url = start_info.resolved_url.ok_or(StartInfoError::MissingResolvedUrl)?;
369        let program = start_info.program.ok_or(StartInfoError::MissingProgram)?;
370        Ok(Self {
371            resolved_url,
372            program,
373            namespace: start_info.ns.unwrap_or_else(|| Vec::new()),
374            outgoing_dir: start_info.outgoing_dir,
375            runtime_dir: start_info.runtime_dir,
376            numbered_handles: start_info.numbered_handles.unwrap_or_else(|| Vec::new()),
377            encoded_config: start_info.encoded_config,
378            break_on_start: start_info.break_on_start,
379            #[cfg(fuchsia_api_level_at_least = "HEAD")]
380            component_instance: start_info.component_instance,
381            #[cfg(fuchsia_api_level_at_least = "HEAD")]
382            escrowed_dictionary: start_info.escrowed_dictionary,
383        })
384    }
385}
386
387impl From<StartInfo> for fcrunner::ComponentStartInfo {
388    fn from(start_info: StartInfo) -> Self {
389        Self {
390            resolved_url: Some(start_info.resolved_url),
391            program: Some(start_info.program),
392            ns: Some(start_info.namespace),
393            outgoing_dir: start_info.outgoing_dir,
394            runtime_dir: start_info.runtime_dir,
395            numbered_handles: Some(start_info.numbered_handles),
396            encoded_config: start_info.encoded_config,
397            break_on_start: start_info.break_on_start,
398            ..Default::default()
399        }
400    }
401}
402
403#[cfg(test)]
404mod tests {
405    use super::*;
406    use test_case::test_case;
407
408    #[test_case(Some("some_url"), Some("some_url".to_owned()) ; "when url is valid")]
409    #[test_case(None, None ; "when url is missing")]
410    fn get_resolved_url_test(maybe_url: Option<&str>, expected: Option<String>) {
411        let start_info = fcrunner::ComponentStartInfo {
412            resolved_url: maybe_url.map(str::to_owned),
413            program: None,
414            ns: None,
415            outgoing_dir: None,
416            runtime_dir: None,
417            ..Default::default()
418        };
419        assert_eq!(get_resolved_url(&start_info), expected,);
420    }
421
422    #[test_case(Some("bin/myexecutable"), Ok("bin/myexecutable".to_owned()) ; "when binary value is valid")]
423    #[test_case(Some("/bin/myexecutable"), Err(StartInfoProgramError::BinaryPathNotRelative) ; "when binary path is not relative")]
424    #[test_case(None, Err(StartInfoProgramError::NotFound) ; "when program stanza is not set")]
425    fn get_program_binary_test(
426        maybe_value: Option<&str>,
427        expected: Result<String, StartInfoProgramError>,
428    ) {
429        let start_info = match maybe_value {
430            Some(value) => new_start_info(Some(new_program_stanza("binary", value))),
431            None => new_start_info(None),
432        };
433        assert_eq!(get_program_binary(&start_info), expected);
434    }
435
436    #[test]
437    fn get_program_binary_test_when_binary_key_is_missing() {
438        let start_info = new_start_info(Some(new_program_stanza("some_other_key", "bin/foo")));
439        assert_eq!(get_program_binary(&start_info), Err(StartInfoProgramError::MissingBinary));
440    }
441
442    #[test_case("bin/myexecutable", Ok("bin/myexecutable".to_owned()) ; "when binary value is valid")]
443    #[test_case("/bin/myexecutable", Err(StartInfoProgramError::BinaryPathNotRelative) ; "when binary path is not relative")]
444    fn get_program_binary_from_dict_test(
445        value: &str,
446        expected: Result<String, StartInfoProgramError>,
447    ) {
448        let program = new_program_stanza("binary", value);
449        assert_eq!(get_program_binary_from_dict(&program), expected);
450    }
451
452    #[test]
453    fn get_program_binary_from_dict_test_when_binary_key_is_missing() {
454        let program = new_program_stanza("some_other_key", "bin/foo");
455        assert_eq!(
456            get_program_binary_from_dict(&program),
457            Err(StartInfoProgramError::MissingBinary)
458        );
459    }
460
461    #[test_case(&[], vec![] ; "when args is empty")]
462    #[test_case(&["a".to_owned()], vec!["a".to_owned()] ; "when args is a")]
463    #[test_case(&["a".to_owned(), "b".to_owned()], vec!["a".to_owned(), "b".to_owned()] ; "when args a and b")]
464    fn get_program_args_test(args: &[String], expected: Vec<String>) {
465        let start_info =
466            new_start_info(Some(new_program_stanza_with_vec(ARGS_KEY, Vec::from(args))));
467        assert_eq!(get_program_args(&start_info).unwrap(), expected);
468    }
469
470    #[test_case(&[], vec![] ; "when args is empty")]
471    #[test_case(&["a".to_owned()], vec!["a".to_owned()] ; "when args is a")]
472    #[test_case(&["a".to_owned(), "b".to_owned()], vec!["a".to_owned(), "b".to_owned()] ; "when args a and b")]
473    fn get_program_args_from_dict_test(args: &[String], expected: Vec<String>) {
474        let program = new_program_stanza_with_vec(ARGS_KEY, Vec::from(args));
475        assert_eq!(get_program_args_from_dict(&program).unwrap(), expected);
476    }
477
478    #[test]
479    fn get_program_args_invalid() {
480        let program = fdata::Dictionary {
481            entries: Some(vec![fdata::DictionaryEntry {
482                key: ARGS_KEY.to_string(),
483                value: Some(Box::new(fdata::DictionaryValue::Str("hello".to_string()))),
484            }]),
485            ..Default::default()
486        };
487        assert_eq!(
488            get_program_args_from_dict(&program),
489            Err(StartInfoProgramError::InvalidStrVec(ARGS_KEY.to_string()))
490        );
491    }
492
493    #[test_case(fdata::DictionaryValue::StrVec(vec!["foo=bar".to_owned(), "bar=baz".to_owned()]), Ok(Some(vec!["foo=bar".to_owned(), "bar=baz".to_owned()])); "when_values_are_valid")]
494    #[test_case(fdata::DictionaryValue::StrVec(vec![]), Ok(None); "when_value_is_empty")]
495    #[test_case(fdata::DictionaryValue::StrVec(vec!["=bad".to_owned()]), Err(StartInfoProgramError::InvalidEnvironValue(0)); "for_environ_with_empty_left_hand_side")]
496    #[test_case(fdata::DictionaryValue::StrVec(vec!["good=".to_owned()]), Ok(Some(vec!["good=".to_owned()])); "for_environ_with_empty_right_hand_side")]
497    #[test_case(fdata::DictionaryValue::StrVec(vec!["no_equal_sign".to_owned()]), Err(StartInfoProgramError::InvalidEnvironValue(0)); "for_environ_with_no_delimiter")]
498    #[test_case(fdata::DictionaryValue::StrVec(vec!["foo=bar=baz".to_owned()]), Ok(Some(vec!["foo=bar=baz".to_owned()])); "for_environ_with_multiple_delimiters")]
499    #[test_case(fdata::DictionaryValue::Str("foo=bar".to_owned()), Err(StartInfoProgramError::InvalidValue(ENVIRON_KEY.to_owned(), "vector of string".to_owned(), "string".to_owned())); "for_environ_as_invalid_type")]
500    fn get_environ_test(
501        value: fdata::DictionaryValue,
502        expected: Result<Option<Vec<String>>, StartInfoProgramError>,
503    ) {
504        let program = fdata::Dictionary {
505            entries: Some(vec![fdata::DictionaryEntry {
506                key: ENVIRON_KEY.to_owned(),
507                value: Some(Box::new(value)),
508            }]),
509            ..Default::default()
510        };
511
512        assert_eq!(get_environ(&program), expected);
513    }
514
515    fn new_start_info(program: Option<fdata::Dictionary>) -> fcrunner::ComponentStartInfo {
516        fcrunner::ComponentStartInfo {
517            program: program,
518            ns: None,
519            outgoing_dir: None,
520            runtime_dir: None,
521            resolved_url: None,
522            ..Default::default()
523        }
524    }
525
526    fn new_program_stanza(key: &str, value: &str) -> fdata::Dictionary {
527        fdata::Dictionary {
528            entries: Some(vec![fdata::DictionaryEntry {
529                key: key.to_owned(),
530                value: Some(Box::new(fdata::DictionaryValue::Str(value.to_owned()))),
531            }]),
532            ..Default::default()
533        }
534    }
535
536    fn new_program_stanza_with_vec(key: &str, values: Vec<String>) -> fdata::Dictionary {
537        fdata::Dictionary {
538            entries: Some(vec![fdata::DictionaryEntry {
539                key: key.to_owned(),
540                value: Some(Box::new(fdata::DictionaryValue::StrVec(values))),
541            }]),
542            ..Default::default()
543        }
544    }
545}
runner/lib.rs

runner/
lib.rs
