starnix_kernel_structured_config/
starnix_kernel_structured_config_rust_config_lib_source.rs

1use fidl::unpersist;
2use fidl_cf_sc_internal_starnixkernelstructuredconfig::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    0xf4, 0x72, 0xd7, 0xaa, 0x71, 0x90, 0x0a, 0x9f, 0x15, 0x2f, 0xea, 0x45, 0x2a, 0xd7, 0x34, 0xcb,
8    0xaf, 0xc4, 0xcd, 0x05, 0x19, 0x69, 0x12, 0x1f, 0xe9, 0x14, 0xdc, 0x23, 0xf2, 0xe3, 0x9b, 0x6e,
9];
10#[derive(Debug)]
11pub struct Config {
12    pub extra_features: Vec<String>,
13}
14impl Config {
15    #[doc = r" Take the config startup handle and parse its contents."]
16    #[doc = r""]
17    #[doc = r" # Panics"]
18    #[doc = r""]
19    #[doc = r" If the config startup handle was already taken or if it is not valid."]
20    pub fn take_from_startup_handle() -> Self {
21        let handle_info = HandleInfo::new(HandleType::ComponentConfigVmo, 0);
22        let config_vmo: zx::Vmo =
23            take_startup_handle(handle_info).expect("Config VMO handle must be present.").into();
24        Self::from_vmo(&config_vmo).expect("Config VMO handle must be valid.")
25    }
26    #[doc = r" Parse `Self` from `vmo`."]
27    pub fn from_vmo(vmo: &zx::Vmo) -> Result<Self, Error> {
28        let config_size = vmo.get_content_size().map_err(Error::GettingContentSize)?;
29        let config_bytes = vmo.read_to_vec(0, config_size).map_err(Error::ReadingConfigBytes)?;
30        Self::from_bytes(&config_bytes)
31    }
32    #[doc = r" Parse `Self` from `bytes`."]
33    pub fn from_bytes(bytes: &[u8]) -> Result<Self, Error> {
34        let (checksum_len_bytes, bytes) = bytes.split_at_checked(2).ok_or(Error::TooFewBytes)?;
35        let checksum_len_bytes: [u8; 2] =
36            checksum_len_bytes.try_into().expect("previous call guaranteed 2 element slice");
37        let checksum_length = u16::from_le_bytes(checksum_len_bytes) as usize;
38        let (observed_checksum, bytes) =
39            bytes.split_at_checked(checksum_length).ok_or(Error::TooFewBytes)?;
40        if observed_checksum != EXPECTED_CHECKSUM {
41            return Err(Error::ChecksumMismatch { observed_checksum: observed_checksum.to_vec() });
42        }
43        let fidl_config: FidlConfig = unpersist(bytes).map_err(Error::Unpersist)?;
44        Ok(Self { extra_features: fidl_config.extra_features })
45    }
46    pub fn record_inspect(&self, inspector_node: &Node) {
47        let arr = inspector_node.create_string_array("extra_features", self.extra_features.len());
48        for i in 0..self.extra_features.len() {
49            arr.set(i, &self.extra_features[i]);
50        }
51        inspector_node.record(arr);
52    }
53}
54#[derive(Debug)]
55pub enum Error {
56    #[doc = r" Failed to read the content size of the VMO."]
57    GettingContentSize(zx::Status),
58    #[doc = r" Failed to read the content of the VMO."]
59    ReadingConfigBytes(zx::Status),
60    #[doc = r" The VMO was too small for this config library."]
61    TooFewBytes,
62    #[doc = r" The VMO's config ABI checksum did not match this library's."]
63    ChecksumMismatch { observed_checksum: Vec<u8> },
64    #[doc = r" Failed to parse the non-checksum bytes of the VMO as this library's FIDL type."]
65    Unpersist(fidl::Error),
66}
67impl std::fmt::Display for Error {
68    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
69        match self {
70            Self::GettingContentSize(status) => {
71                write!(f, "Failed to get content size: {status}")
72            }
73            Self::ReadingConfigBytes(status) => {
74                write!(f, "Failed to read VMO content: {status}")
75            }
76            Self::TooFewBytes => {
77                write!(f, "VMO content is not large enough for this config library.")
78            }
79            Self::ChecksumMismatch { observed_checksum } => {
80                write!(
81                    f,
82                    "ABI checksum mismatch, expected {:?}, got {:?}",
83                    EXPECTED_CHECKSUM, observed_checksum,
84                )
85            }
86            Self::Unpersist(fidl_error) => {
87                write!(f, "Failed to parse contents of config VMO: {fidl_error}")
88            }
89        }
90    }
91}
92impl std::error::Error for Error {
93    #[allow(unused_parens, reason = "rustfmt errors without parens here")]
94    fn source(&self) -> Option<(&'_ (dyn std::error::Error + 'static))> {
95        match self {
96            Self::GettingContentSize(ref status) | Self::ReadingConfigBytes(ref status) => {
97                Some(status)
98            }
99            Self::TooFewBytes => None,
100            Self::ChecksumMismatch { .. } => None,
101            Self::Unpersist(ref fidl_error) => Some(fidl_error),
102        }
103    }
104    fn description(&self) -> &str {
105        match self {
106            Self::GettingContentSize(_) => "getting content size",
107            Self::ReadingConfigBytes(_) => "reading VMO contents",
108            Self::TooFewBytes => "VMO contents too small",
109            Self::ChecksumMismatch { .. } => "ABI checksum mismatch",
110            Self::Unpersist(_) => "FIDL parsing error",
111        }
112    }
113}
starnix_kernel_structured_config/starnix_kernel_structured_config_rust_config_lib_source.rs

starnix_kernel_structured_config/
starnix_kernel_structured_config_rust_config_lib_source.rs
