config_lib/
config_lib_rust_config_lib_source.rs

1use fidl::unpersist;
2use fidl_cf_sc_internal_configlib::Config as FidlConfig;
3use fuchsia_inspect::{ArrayProperty, Node};
4use fuchsia_runtime::{take_startup_handle, HandleInfo, HandleType};
5use std::convert::TryInto;
6const EXPECTED_CHECKSUM: &[u8] = &[
7    0x1e, 0x2c, 0x8c, 0x11, 0x78, 0x21, 0x1b, 0xf4, 0x53, 0xba, 0x24, 0x7c, 0x85, 0xfa, 0x38, 0x87,
8    0xf2, 0xcc, 0x60, 0x5d, 0xdb, 0xba, 0x3d, 0xe6, 0x07, 0x44, 0xa1, 0x0e, 0x17, 0xa6, 0x12, 0x97,
9];
10#[derive(Debug)]
11pub struct Config {
12    pub echo_bool: bool,
13    pub echo_num: u64,
14    pub echo_string: String,
15    pub echo_string_vector: Vec<String>,
16}
17impl Config {
18    #[doc = r" Take the config startup handle and parse its contents."]
19    #[doc = r""]
20    #[doc = r" # Panics"]
21    #[doc = r""]
22    #[doc = r" If the config startup handle was already taken or if it is not valid."]
23    pub fn take_from_startup_handle() -> Self {
24        let handle_info = HandleInfo::new(HandleType::ComponentConfigVmo, 0);
25        let config_vmo: zx::Vmo =
26            take_startup_handle(handle_info).expect("Config VMO handle must be present.").into();
27        Self::from_vmo(&config_vmo).expect("Config VMO handle must be valid.")
28    }
29    #[doc = r" Parse `Self` from `vmo`."]
30    pub fn from_vmo(vmo: &zx::Vmo) -> Result<Self, Error> {
31        let config_size = vmo.get_content_size().map_err(Error::GettingContentSize)?;
32        let config_bytes = vmo.read_to_vec(0, config_size).map_err(Error::ReadingConfigBytes)?;
33        Self::from_bytes(&config_bytes)
34    }
35    #[doc = r" Parse `Self` from `bytes`."]
36    pub fn from_bytes(bytes: &[u8]) -> Result<Self, Error> {
37        let (checksum_len_bytes, bytes) = bytes.split_at_checked(2).ok_or(Error::TooFewBytes)?;
38        let checksum_len_bytes: [u8; 2] =
39            checksum_len_bytes.try_into().expect("previous call guaranteed 2 element slice");
40        let checksum_length = u16::from_le_bytes(checksum_len_bytes) as usize;
41        let (observed_checksum, bytes) =
42            bytes.split_at_checked(checksum_length).ok_or(Error::TooFewBytes)?;
43        if observed_checksum != EXPECTED_CHECKSUM {
44            return Err(Error::ChecksumMismatch { observed_checksum: observed_checksum.to_vec() });
45        }
46        let fidl_config: FidlConfig = unpersist(bytes).map_err(Error::Unpersist)?;
47        Ok(Self {
48            echo_bool: fidl_config.echo_bool,
49            echo_num: fidl_config.echo_num,
50            echo_string: fidl_config.echo_string,
51            echo_string_vector: fidl_config.echo_string_vector,
52        })
53    }
54    pub fn record_inspect(&self, inspector_node: &Node) {
55        inspector_node.record_bool("echo_bool", self.echo_bool);
56        inspector_node.record_uint("echo_num", self.echo_num);
57        inspector_node.record_string("echo_string", &self.echo_string);
58        let arr =
59            inspector_node.create_string_array("echo_string_vector", self.echo_string_vector.len());
60        for i in 0..self.echo_string_vector.len() {
61            arr.set(i, &self.echo_string_vector[i]);
62        }
63        inspector_node.record(arr);
64    }
65}
66#[derive(Debug)]
67pub enum Error {
68    #[doc = r" Failed to read the content size of the VMO."]
69    GettingContentSize(zx::Status),
70    #[doc = r" Failed to read the content of the VMO."]
71    ReadingConfigBytes(zx::Status),
72    #[doc = r" The VMO was too small for this config library."]
73    TooFewBytes,
74    #[doc = r" The VMO's config ABI checksum did not match this library's."]
75    ChecksumMismatch { observed_checksum: Vec<u8> },
76    #[doc = r" Failed to parse the non-checksum bytes of the VMO as this library's FIDL type."]
77    Unpersist(fidl::Error),
78}
79impl std::fmt::Display for Error {
80    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
81        match self {
82            Self::GettingContentSize(status) => {
83                write!(f, "Failed to get content size: {status}")
84            }
85            Self::ReadingConfigBytes(status) => {
86                write!(f, "Failed to read VMO content: {status}")
87            }
88            Self::TooFewBytes => {
89                write!(f, "VMO content is not large enough for this config library.")
90            }
91            Self::ChecksumMismatch { observed_checksum } => {
92                write!(
93                    f,
94                    "ABI checksum mismatch, expected {:?}, got {:?}",
95                    EXPECTED_CHECKSUM, observed_checksum,
96                )
97            }
98            Self::Unpersist(fidl_error) => {
99                write!(f, "Failed to parse contents of config VMO: {fidl_error}")
100            }
101        }
102    }
103}
104impl std::error::Error for Error {
105    #[allow(unused_parens, reason = "rustfmt errors without parens here")]
106    fn source(&self) -> Option<(&'_ (dyn std::error::Error + 'static))> {
107        match self {
108            Self::GettingContentSize(ref status) | Self::ReadingConfigBytes(ref status) => {
109                Some(status)
110            }
111            Self::TooFewBytes => None,
112            Self::ChecksumMismatch { .. } => None,
113            Self::Unpersist(ref fidl_error) => Some(fidl_error),
114        }
115    }
116    fn description(&self) -> &str {
117        match self {
118            Self::GettingContentSize(_) => "getting content size",
119            Self::ReadingConfigBytes(_) => "reading VMO contents",
120            Self::TooFewBytes => "VMO contents too small",
121            Self::ChecksumMismatch { .. } => "ABI checksum mismatch",
122            Self::Unpersist(_) => "FIDL parsing error",
123        }
124    }
125}
config_lib/config_lib_rust_config_lib_source.rs

config_lib/
config_lib_rust_config_lib_source.rs
