ns3_config/
config_lib_rust_config_lib_source.rs

1use fidl::unpersist;
2use fidl_cf_sc_internal_ns3config::Config as FidlConfig;
3use fuchsia_inspect::Node;
4use fuchsia_runtime::{take_startup_handle, HandleInfo, HandleType};
5use std::convert::TryInto;
6const EXPECTED_CHECKSUM: &[u8] = &[
7    0x1d, 0xa6, 0xb4, 0xe2, 0xe3, 0xab, 0x9c, 0x6e, 0xdb, 0x49, 0x2f, 0x8e, 0xe1, 0xff, 0xe2, 0x2b,
8    0x3d, 0xd6, 0x4c, 0xda, 0x7c, 0xd7, 0x77, 0x92, 0x12, 0xa2, 0x8d, 0xdc, 0x82, 0x57, 0x8e, 0xa1,
9];
10#[derive(Debug)]
11pub struct Config {
12    pub debug_logs: bool,
13    pub num_threads: u8,
14    pub opaque_iids: bool,
15    pub suspend_enabled: bool,
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            debug_logs: fidl_config.debug_logs,
49            num_threads: fidl_config.num_threads,
50            opaque_iids: fidl_config.opaque_iids,
51            suspend_enabled: fidl_config.suspend_enabled,
52        })
53    }
54    pub fn record_inspect(&self, inspector_node: &Node) {
55        inspector_node.record_bool("debug_logs", self.debug_logs);
56        inspector_node.record_uint("num_threads", self.num_threads as u64);
57        inspector_node.record_bool("opaque_iids", self.opaque_iids);
58        inspector_node.record_bool("suspend_enabled", self.suspend_enabled);
59    }
60}
61#[derive(Debug)]
62pub enum Error {
63    #[doc = r" Failed to read the content size of the VMO."]
64    GettingContentSize(zx::Status),
65    #[doc = r" Failed to read the content of the VMO."]
66    ReadingConfigBytes(zx::Status),
67    #[doc = r" The VMO was too small for this config library."]
68    TooFewBytes,
69    #[doc = r" The VMO's config ABI checksum did not match this library's."]
70    ChecksumMismatch { observed_checksum: Vec<u8> },
71    #[doc = r" Failed to parse the non-checksum bytes of the VMO as this library's FIDL type."]
72    Unpersist(fidl::Error),
73}
74impl std::fmt::Display for Error {
75    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
76        match self {
77            Self::GettingContentSize(status) => {
78                write!(f, "Failed to get content size: {status}")
79            }
80            Self::ReadingConfigBytes(status) => {
81                write!(f, "Failed to read VMO content: {status}")
82            }
83            Self::TooFewBytes => {
84                write!(f, "VMO content is not large enough for this config library.")
85            }
86            Self::ChecksumMismatch { observed_checksum } => {
87                write!(
88                    f,
89                    "ABI checksum mismatch, expected {:?}, got {:?}",
90                    EXPECTED_CHECKSUM, observed_checksum,
91                )
92            }
93            Self::Unpersist(fidl_error) => {
94                write!(f, "Failed to parse contents of config VMO: {fidl_error}")
95            }
96        }
97    }
98}
99impl std::error::Error for Error {
100    #[allow(unused_parens, reason = "rustfmt errors without parens here")]
101    fn source(&self) -> Option<(&'_ (dyn std::error::Error + 'static))> {
102        match self {
103            Self::GettingContentSize(ref status) | Self::ReadingConfigBytes(ref status) => {
104                Some(status)
105            }
106            Self::TooFewBytes => None,
107            Self::ChecksumMismatch { .. } => None,
108            Self::Unpersist(ref fidl_error) => Some(fidl_error),
109        }
110    }
111    fn description(&self) -> &str {
112        match self {
113            Self::GettingContentSize(_) => "getting content size",
114            Self::ReadingConfigBytes(_) => "reading VMO contents",
115            Self::TooFewBytes => "VMO contents too small",
116            Self::ChecksumMismatch { .. } => "ABI checksum mismatch",
117            Self::Unpersist(_) => "FIDL parsing error",
118        }
119    }
120}
ns3_config/config_lib_rust_config_lib_source.rs

ns3_config/
config_lib_rust_config_lib_source.rs
