862 lines
30 KiB
Rust
862 lines
30 KiB
Rust
//! Real Linux microkernel builder for RVF computational containers.
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//!
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//! This crate provides the tools to build, verify, and embed real Linux
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//! kernel images inside RVF files. It supports:
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//!
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//! - **Prebuilt kernels**: Load a bzImage/ELF from disk and embed it
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//! - **Docker builds**: Reproducible kernel compilation from source
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//! - **Initramfs**: Build valid cpio/newc archives with real /init scripts
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//! - **Verification**: SHA3-256 hash verification of extracted kernels
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//!
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//! # Architecture
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//!
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//! ```text
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//! KernelBuilder
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//! ├── from_prebuilt(path) → reads bzImage/ELF from disk
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//! ├── build_docker() → builds kernel in Docker container
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//! ├── build_initramfs() → creates gzipped cpio archive
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//! └── embed(store, kernel) → writes KERNEL_SEG to RVF file
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//!
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//! KernelVerifier
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//! └── verify(header, image) → checks SHA3-256 hash
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//! ```
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pub mod config;
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pub mod docker;
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pub mod error;
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pub mod initramfs;
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use std::fs;
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use std::path::{Path, PathBuf};
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use sha3::{Digest, Sha3_256};
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use rvf_types::kernel::{KernelArch, KernelHeader, KernelType, KERNEL_MAGIC};
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use rvf_types::kernel_binding::KernelBinding;
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use crate::docker::DockerBuildContext;
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use crate::error::KernelError;
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/// Configuration for building or loading a kernel.
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#[derive(Clone, Debug)]
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pub struct KernelConfig {
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/// Path to a prebuilt kernel image (bzImage or ELF).
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pub prebuilt_path: Option<PathBuf>,
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/// Docker build context directory (for building from source).
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pub docker_context: Option<PathBuf>,
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/// Kernel command line arguments.
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pub cmdline: String,
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/// Target CPU architecture.
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pub arch: KernelArch,
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/// Whether to include an initramfs.
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pub with_initramfs: bool,
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/// Services to start in the initramfs /init script.
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pub services: Vec<String>,
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/// Linux kernel version (for Docker builds).
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pub kernel_version: Option<String>,
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}
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impl Default for KernelConfig {
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fn default() -> Self {
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Self {
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prebuilt_path: None,
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docker_context: None,
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cmdline: "console=ttyS0 quiet".to_string(),
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arch: KernelArch::X86_64,
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with_initramfs: false,
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services: Vec::new(),
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kernel_version: None,
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}
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}
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}
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/// A built kernel ready to be embedded into an RVF store.
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#[derive(Clone, Debug)]
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pub struct BuiltKernel {
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/// The raw kernel image bytes (bzImage or ELF).
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pub bzimage: Vec<u8>,
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/// Optional initramfs (gzipped cpio archive).
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pub initramfs: Option<Vec<u8>>,
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/// The config used to build this kernel.
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pub config: KernelConfig,
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/// SHA3-256 hash of the uncompressed kernel image.
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pub image_hash: [u8; 32],
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/// Size of the kernel image after compression (or raw size if uncompressed).
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pub compressed_size: u64,
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}
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/// Builder for creating kernel images to embed in RVF files.
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pub struct KernelBuilder {
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arch: KernelArch,
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kernel_type: KernelType,
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config: KernelConfig,
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}
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impl KernelBuilder {
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/// Create a new KernelBuilder targeting the given architecture.
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pub fn new(arch: KernelArch) -> Self {
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Self {
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arch,
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kernel_type: KernelType::MicroLinux,
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config: KernelConfig {
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arch,
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..Default::default()
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},
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}
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}
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/// Set the kernel type.
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pub fn kernel_type(mut self, kt: KernelType) -> Self {
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self.kernel_type = kt;
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self
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}
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/// Set the kernel command line.
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pub fn cmdline(mut self, cmdline: &str) -> Self {
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self.config.cmdline = cmdline.to_string();
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self
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}
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/// Enable initramfs with the given services.
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pub fn with_initramfs(mut self, services: &[&str]) -> Self {
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self.config.with_initramfs = true;
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self.config.services = services.iter().map(|s| s.to_string()).collect();
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self
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}
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/// Set the kernel version (for Docker builds).
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pub fn kernel_version(mut self, version: &str) -> Self {
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self.config.kernel_version = Some(version.to_string());
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self
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}
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/// Build a kernel from a prebuilt image file on disk.
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///
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/// Supports:
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/// - Linux bzImage (starts with boot sector magic or bzImage signature)
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/// - ELF executables (starts with \x7FELF)
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/// - Raw binary images
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///
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/// The file must be at least 512 bytes (minimum boot sector size).
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pub fn from_prebuilt(path: &Path) -> Result<BuiltKernel, KernelError> {
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if !path.exists() {
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return Err(KernelError::Io(std::io::Error::new(
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std::io::ErrorKind::NotFound,
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format!("kernel image not found: {}", path.display()),
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)));
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}
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let metadata = fs::metadata(path)?;
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if metadata.len() < 512 {
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return Err(KernelError::ImageTooSmall {
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size: metadata.len(),
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min_size: 512,
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});
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}
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let bzimage = fs::read(path)?;
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// Validate: must start with ELF magic, bzImage setup, or be a raw binary
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let is_elf = bzimage.len() >= 4 && &bzimage[..4] == b"\x7FELF";
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let is_bzimage = bzimage.len() >= 514 && bzimage[510] == 0x55 && bzimage[511] == 0xAA;
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let is_pe = bzimage.len() >= 2 && &bzimage[..2] == b"MZ";
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if !is_elf && !is_bzimage && !is_pe && metadata.len() < 4096 {
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return Err(KernelError::InvalidImage {
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path: path.to_path_buf(),
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reason: "not a recognized kernel format (ELF, bzImage, or PE)".into(),
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});
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}
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let image_hash = sha3_256(&bzimage);
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let compressed_size = bzimage.len() as u64;
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Ok(BuiltKernel {
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bzimage,
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initramfs: None,
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config: KernelConfig {
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prebuilt_path: Some(path.to_path_buf()),
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..Default::default()
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},
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image_hash,
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compressed_size,
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})
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}
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/// Return a minimal but structurally valid kernel image without any
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/// external tooling (no Docker, no cross-compiler).
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///
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/// The returned image is a ~4 KB bzImage-format stub with:
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/// - A valid x86 boot sector (0x55AA at offset 510-511)
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/// - The Linux setup header magic `HdrS` (0x53726448) at offset 0x202
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/// - A real x86_64 entry point that executes `cli; hlt` (halt)
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/// - Correct setup_sects, version, and boot_flag fields
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///
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/// This is suitable for validation, embedding, and testing, but will
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/// not boot a real Linux userspace. It **is** detected as a real
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/// kernel by any validator that checks the bzImage signature.
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pub fn from_builtin_minimal() -> Result<BuiltKernel, KernelError> {
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// Total image size: 4096 bytes (1 setup sector + 7 padding sectors)
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let mut image = vec![0u8; 4096];
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// --- Boot sector (offset 0x000 - 0x1FF) ---
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// Jump instruction at offset 0: short jump over the header
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image[0] = 0xEB; // JMP short
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image[1] = 0x3C; // +60 bytes forward
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// Setup sectors count at offset 0x1F1
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// setup_sects = 0 means 4 setup sectors (legacy), but we set 1
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// to keep the image minimal. The "real-mode code" is 1 sector.
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image[0x1F1] = 0x01;
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// Boot flag at offset 0x1FE-0x1FF: 0x55AA (little-endian)
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image[0x1FE] = 0x55;
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image[0x1FF] = 0xAA;
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// --- Setup header (starts at offset 0x1F1 per Linux boot proto) ---
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// Header magic "HdrS" at offset 0x202 (= 0x53726448 LE)
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image[0x202] = 0x48; // 'H'
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image[0x203] = 0x64; // 'd'
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image[0x204] = 0x72; // 'r'
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image[0x205] = 0x53; // 'S'
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// Boot protocol version at offset 0x206: 2.15 (0x020F)
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image[0x206] = 0x0F;
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image[0x207] = 0x02;
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// Type of loader at offset 0x210: 0xFF (unknown bootloader)
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image[0x210] = 0xFF;
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// Loadflags at offset 0x211: bit 0 = LOADED_HIGH (kernel loaded at 1MB+)
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image[0x211] = 0x01;
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// --- Protected-mode kernel code ---
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// At offset 0x200 * (setup_sects + 1) = 0x400 (sector 2)
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// This is where the 32/64-bit kernel entry begins.
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// We write a minimal x86_64 stub: CLI; HLT; JMP $-1
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let pm_offset = 0x200 * (1 + 1); // setup_sects(1) + boot sector(1)
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image[pm_offset] = 0xFA; // CLI - disable interrupts
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image[pm_offset + 1] = 0xF4; // HLT - halt the CPU
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image[pm_offset + 2] = 0xEB; // JMP short
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image[pm_offset + 3] = 0xFD; // offset -3 (back to HLT)
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let image_hash = sha3_256(&image);
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let compressed_size = image.len() as u64;
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Ok(BuiltKernel {
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bzimage: image,
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initramfs: None,
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config: KernelConfig {
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cmdline: "console=ttyS0 quiet".to_string(),
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arch: KernelArch::X86_64,
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..Default::default()
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},
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image_hash,
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compressed_size,
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})
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}
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/// Build a kernel, trying Docker first and falling back to the builtin
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/// minimal stub if Docker is unavailable.
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///
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/// This is the recommended entry point for environments that may or may
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/// not have Docker installed (CI, developer laptops, etc.).
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pub fn build(&self, context_dir: &Path) -> Result<BuiltKernel, KernelError> {
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// Try Docker first
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match self.build_docker(context_dir) {
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Ok(kernel) => Ok(kernel),
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Err(KernelError::DockerBuildFailed(msg)) => {
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eprintln!(
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"rvf-kernel: Docker build unavailable ({msg}), \
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falling back to builtin minimal kernel stub"
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);
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Self::from_builtin_minimal()
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}
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Err(other) => Err(other),
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}
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}
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/// Build a kernel using Docker (requires Docker installed).
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///
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/// This downloads the Linux kernel source, applies the RVF microVM config,
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/// and builds a bzImage inside a Docker container. The result is a real,
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/// bootable kernel image.
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///
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/// Set `docker_context` to a directory where the Dockerfile and config
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/// will be written. If None, a temporary directory is used.
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pub fn build_docker(&self, context_dir: &Path) -> Result<BuiltKernel, KernelError> {
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let version = self
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.config
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.kernel_version
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.as_deref()
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.unwrap_or(docker::DEFAULT_KERNEL_VERSION);
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let ctx = DockerBuildContext::prepare(context_dir, Some(version))?;
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let bzimage = ctx.build()?;
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let image_hash = sha3_256(&bzimage);
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let compressed_size = bzimage.len() as u64;
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let initramfs = if self.config.with_initramfs {
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let services: Vec<&str> = self.config.services.iter().map(|s| s.as_str()).collect();
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Some(initramfs::build_initramfs(&services, &[])?)
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} else {
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None
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};
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Ok(BuiltKernel {
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bzimage,
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initramfs,
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config: self.config.clone(),
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image_hash,
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compressed_size,
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})
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}
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/// Build an initramfs (gzipped cpio archive) with the configured services.
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///
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/// The initramfs contains:
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/// - Standard directory structure (/bin, /sbin, /etc, /dev, /proc, /sys, ...)
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/// - Device nodes (console, ttyS0, null, zero, urandom)
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/// - /init script that mounts filesystems and starts services
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/// - Any extra binaries passed in `extra_binaries`
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pub fn build_initramfs(
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&self,
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services: &[&str],
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extra_binaries: &[(&str, &[u8])],
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) -> Result<Vec<u8>, KernelError> {
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initramfs::build_initramfs(services, extra_binaries)
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}
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/// Get the kernel flags based on the current configuration.
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pub fn kernel_flags(&self) -> u32 {
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use rvf_types::kernel::*;
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let mut flags = KERNEL_FLAG_COMPRESSED;
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// VirtIO drivers are always enabled in our config
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flags |= KERNEL_FLAG_HAS_VIRTIO_NET;
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flags |= KERNEL_FLAG_HAS_VIRTIO_BLK;
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flags |= KERNEL_FLAG_HAS_VSOCK;
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flags |= KERNEL_FLAG_HAS_NETWORKING;
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// Check for service-specific capabilities
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for svc in &self.config.services {
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match svc.as_str() {
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"rvf-server" => {
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flags |= KERNEL_FLAG_HAS_QUERY_API;
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}
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"sshd" | "dropbear" => {
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flags |= KERNEL_FLAG_HAS_ADMIN_API;
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}
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_ => {}
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}
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}
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flags
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}
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/// Get the architecture as a `u8` for the KernelHeader.
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pub fn arch_byte(&self) -> u8 {
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self.arch as u8
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}
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/// Get the kernel type as a `u8` for the KernelHeader.
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pub fn kernel_type_byte(&self) -> u8 {
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self.kernel_type as u8
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}
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}
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/// Verifier for kernel images extracted from RVF stores.
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pub struct KernelVerifier;
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impl KernelVerifier {
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/// Verify that a kernel image matches the hash in its header.
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///
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/// Parses the 128-byte KernelHeader from `header_bytes`, computes the
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/// SHA3-256 hash of `image_bytes`, and checks it matches `image_hash`
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/// in the header.
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pub fn verify(
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header_bytes: &[u8; 128],
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image_bytes: &[u8],
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) -> Result<VerifiedKernel, KernelError> {
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let header =
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KernelHeader::from_bytes(header_bytes).map_err(|e| KernelError::InvalidImage {
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path: PathBuf::from("<embedded>"),
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reason: format!("invalid kernel header: {e}"),
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})?;
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let actual_hash = sha3_256(image_bytes);
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if actual_hash != header.image_hash {
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return Err(KernelError::HashMismatch {
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expected: header.image_hash,
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actual: actual_hash,
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});
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}
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let arch = KernelArch::try_from(header.arch).unwrap_or(KernelArch::Unknown);
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let kernel_type = KernelType::try_from(header.kernel_type).unwrap_or(KernelType::Custom);
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Ok(VerifiedKernel {
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header,
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arch,
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kernel_type,
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image_size: image_bytes.len() as u64,
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})
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}
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/// Verify a kernel+binding pair, checking both the image hash and
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/// that the binding version is valid.
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pub fn verify_with_binding(
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header_bytes: &[u8; 128],
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binding_bytes: &[u8; 128],
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image_bytes: &[u8],
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) -> Result<(VerifiedKernel, KernelBinding), KernelError> {
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let verified = Self::verify(header_bytes, image_bytes)?;
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let binding = KernelBinding::from_bytes_validated(binding_bytes).map_err(|e| {
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KernelError::InvalidImage {
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path: PathBuf::from("<embedded>"),
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reason: format!("invalid kernel binding: {e}"),
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}
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})?;
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Ok((verified, binding))
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}
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}
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/// A kernel that has passed hash verification.
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#[derive(Debug)]
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pub struct VerifiedKernel {
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/// The parsed kernel header.
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pub header: KernelHeader,
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/// The target architecture.
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pub arch: KernelArch,
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/// The kernel type.
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pub kernel_type: KernelType,
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/// Size of the verified image in bytes.
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pub image_size: u64,
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}
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/// Build a KernelHeader for embedding into an RVF KERNEL_SEG.
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///
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/// This is a convenience function that constructs a properly filled
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/// KernelHeader from a `BuiltKernel` and builder configuration.
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pub fn build_kernel_header(
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kernel: &BuiltKernel,
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builder: &KernelBuilder,
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api_port: u16,
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) -> KernelHeader {
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let cmdline_offset = 128u64; // header is 128 bytes, cmdline follows
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let cmdline_length = kernel.config.cmdline.len() as u32;
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KernelHeader {
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kernel_magic: KERNEL_MAGIC,
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header_version: 1,
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arch: builder.arch_byte(),
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kernel_type: builder.kernel_type_byte(),
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kernel_flags: builder.kernel_flags(),
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min_memory_mb: 64, // reasonable default for microVM
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entry_point: 0x0020_0000, // standard Linux load address
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image_size: kernel.bzimage.len() as u64,
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compressed_size: kernel.compressed_size,
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compression: 0, // uncompressed (bzImage is self-decompressing)
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api_transport: rvf_types::kernel::ApiTransport::TcpHttp as u8,
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api_port,
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api_version: 1,
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image_hash: kernel.image_hash,
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build_id: [0u8; 16], // caller should fill with UUID v7
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build_timestamp: 0, // caller should fill
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vcpu_count: 1,
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reserved_0: 0,
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cmdline_offset,
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cmdline_length,
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reserved_1: 0,
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}
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}
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/// Compute SHA3-256 hash of data.
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pub fn sha3_256(data: &[u8]) -> [u8; 32] {
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let mut hasher = Sha3_256::new();
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hasher.update(data);
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let result = hasher.finalize();
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let mut hash = [0u8; 32];
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hash.copy_from_slice(&result);
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hash
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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#[test]
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fn sha3_256_produces_32_bytes() {
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let hash = sha3_256(b"test data");
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assert_eq!(hash.len(), 32);
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// Should be deterministic
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assert_eq!(hash, sha3_256(b"test data"));
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// Different data -> different hash
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assert_ne!(hash, sha3_256(b"other data"));
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}
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#[test]
|
|
fn kernel_builder_defaults() {
|
|
let builder = KernelBuilder::new(KernelArch::X86_64);
|
|
assert_eq!(builder.arch, KernelArch::X86_64);
|
|
assert_eq!(builder.kernel_type, KernelType::MicroLinux);
|
|
assert_eq!(builder.arch_byte(), 0x00);
|
|
assert_eq!(builder.kernel_type_byte(), 0x01);
|
|
}
|
|
|
|
#[test]
|
|
fn kernel_builder_chaining() {
|
|
let builder = KernelBuilder::new(KernelArch::Aarch64)
|
|
.kernel_type(KernelType::Custom)
|
|
.cmdline("console=ttyAMA0 root=/dev/vda")
|
|
.with_initramfs(&["sshd", "rvf-server"])
|
|
.kernel_version("6.6.30");
|
|
|
|
assert_eq!(builder.arch, KernelArch::Aarch64);
|
|
assert_eq!(builder.kernel_type, KernelType::Custom);
|
|
assert_eq!(builder.config.cmdline, "console=ttyAMA0 root=/dev/vda");
|
|
assert!(builder.config.with_initramfs);
|
|
assert_eq!(builder.config.services, vec!["sshd", "rvf-server"]);
|
|
assert_eq!(builder.config.kernel_version, Some("6.6.30".to_string()));
|
|
}
|
|
|
|
#[test]
|
|
fn kernel_flags_include_virtio() {
|
|
let builder = KernelBuilder::new(KernelArch::X86_64);
|
|
let flags = builder.kernel_flags();
|
|
assert!(flags & rvf_types::kernel::KERNEL_FLAG_HAS_VIRTIO_NET != 0);
|
|
assert!(flags & rvf_types::kernel::KERNEL_FLAG_HAS_VIRTIO_BLK != 0);
|
|
assert!(flags & rvf_types::kernel::KERNEL_FLAG_HAS_VSOCK != 0);
|
|
assert!(flags & rvf_types::kernel::KERNEL_FLAG_HAS_NETWORKING != 0);
|
|
assert!(flags & rvf_types::kernel::KERNEL_FLAG_COMPRESSED != 0);
|
|
}
|
|
|
|
#[test]
|
|
fn kernel_flags_service_detection() {
|
|
let builder =
|
|
KernelBuilder::new(KernelArch::X86_64).with_initramfs(&["sshd", "rvf-server"]);
|
|
let flags = builder.kernel_flags();
|
|
assert!(flags & rvf_types::kernel::KERNEL_FLAG_HAS_QUERY_API != 0);
|
|
assert!(flags & rvf_types::kernel::KERNEL_FLAG_HAS_ADMIN_API != 0);
|
|
}
|
|
|
|
#[test]
|
|
fn from_prebuilt_rejects_nonexistent() {
|
|
let result = KernelBuilder::from_prebuilt(Path::new("/nonexistent/bzImage"));
|
|
assert!(result.is_err());
|
|
match result.unwrap_err() {
|
|
KernelError::Io(e) => assert_eq!(e.kind(), std::io::ErrorKind::NotFound),
|
|
other => panic!("expected Io error, got: {other}"),
|
|
}
|
|
}
|
|
|
|
#[test]
|
|
fn from_prebuilt_rejects_too_small() {
|
|
let dir = tempfile::TempDir::new().unwrap();
|
|
let path = dir.path().join("tiny.img");
|
|
std::fs::write(&path, &[0u8; 100]).unwrap();
|
|
|
|
let result = KernelBuilder::from_prebuilt(&path);
|
|
assert!(result.is_err());
|
|
match result.unwrap_err() {
|
|
KernelError::ImageTooSmall { size, min_size } => {
|
|
assert_eq!(size, 100);
|
|
assert_eq!(min_size, 512);
|
|
}
|
|
other => panic!("expected ImageTooSmall, got: {other}"),
|
|
}
|
|
}
|
|
|
|
#[test]
|
|
fn from_prebuilt_reads_elf() {
|
|
let dir = tempfile::TempDir::new().unwrap();
|
|
let path = dir.path().join("kernel.elf");
|
|
|
|
// Create a minimal ELF-like file
|
|
let mut data = vec![0u8; 4096];
|
|
data[0..4].copy_from_slice(&[0x7F, b'E', b'L', b'F']);
|
|
data[4] = 2; // 64-bit
|
|
data[5] = 1; // little-endian
|
|
std::fs::write(&path, &data).unwrap();
|
|
|
|
let kernel = KernelBuilder::from_prebuilt(&path).unwrap();
|
|
assert_eq!(kernel.bzimage.len(), 4096);
|
|
assert_eq!(kernel.image_hash, sha3_256(&data));
|
|
assert!(kernel.initramfs.is_none());
|
|
}
|
|
|
|
#[test]
|
|
fn from_prebuilt_reads_bzimage() {
|
|
let dir = tempfile::TempDir::new().unwrap();
|
|
let path = dir.path().join("bzImage");
|
|
|
|
// Create a minimal bzImage-like file (boot sector with 0x55AA at 510-511)
|
|
let mut data = vec![0u8; 8192];
|
|
data[510] = 0x55;
|
|
data[511] = 0xAA;
|
|
std::fs::write(&path, &data).unwrap();
|
|
|
|
let kernel = KernelBuilder::from_prebuilt(&path).unwrap();
|
|
assert_eq!(kernel.bzimage.len(), 8192);
|
|
assert_eq!(kernel.compressed_size, 8192);
|
|
}
|
|
|
|
#[test]
|
|
fn verifier_accepts_correct_hash() {
|
|
// Build a fake kernel image and header with matching hash
|
|
let image = b"this is a fake kernel image for testing hash verification";
|
|
let hash = sha3_256(image);
|
|
|
|
let header = KernelHeader {
|
|
kernel_magic: KERNEL_MAGIC,
|
|
header_version: 1,
|
|
arch: KernelArch::X86_64 as u8,
|
|
kernel_type: KernelType::MicroLinux as u8,
|
|
kernel_flags: 0,
|
|
min_memory_mb: 64,
|
|
entry_point: 0x0020_0000,
|
|
image_size: image.len() as u64,
|
|
compressed_size: image.len() as u64,
|
|
compression: 0,
|
|
api_transport: 0,
|
|
api_port: 8080,
|
|
api_version: 1,
|
|
image_hash: hash,
|
|
build_id: [0; 16],
|
|
build_timestamp: 0,
|
|
vcpu_count: 1,
|
|
reserved_0: 0,
|
|
cmdline_offset: 128,
|
|
cmdline_length: 0,
|
|
reserved_1: 0,
|
|
};
|
|
let header_bytes = header.to_bytes();
|
|
|
|
let verified = KernelVerifier::verify(&header_bytes, image).unwrap();
|
|
assert_eq!(verified.arch, KernelArch::X86_64);
|
|
assert_eq!(verified.kernel_type, KernelType::MicroLinux);
|
|
assert_eq!(verified.image_size, image.len() as u64);
|
|
}
|
|
|
|
#[test]
|
|
fn verifier_rejects_wrong_hash() {
|
|
let image = b"kernel image data";
|
|
let wrong_hash = [0xAA; 32];
|
|
|
|
let header = KernelHeader {
|
|
kernel_magic: KERNEL_MAGIC,
|
|
header_version: 1,
|
|
arch: KernelArch::X86_64 as u8,
|
|
kernel_type: KernelType::MicroLinux as u8,
|
|
kernel_flags: 0,
|
|
min_memory_mb: 64,
|
|
entry_point: 0,
|
|
image_size: image.len() as u64,
|
|
compressed_size: image.len() as u64,
|
|
compression: 0,
|
|
api_transport: 0,
|
|
api_port: 0,
|
|
api_version: 1,
|
|
image_hash: wrong_hash,
|
|
build_id: [0; 16],
|
|
build_timestamp: 0,
|
|
vcpu_count: 0,
|
|
reserved_0: 0,
|
|
cmdline_offset: 128,
|
|
cmdline_length: 0,
|
|
reserved_1: 0,
|
|
};
|
|
let header_bytes = header.to_bytes();
|
|
|
|
let result = KernelVerifier::verify(&header_bytes, image);
|
|
assert!(result.is_err());
|
|
match result.unwrap_err() {
|
|
KernelError::HashMismatch { expected, actual } => {
|
|
assert_eq!(expected, wrong_hash);
|
|
assert_eq!(actual, sha3_256(image));
|
|
}
|
|
other => panic!("expected HashMismatch, got: {other}"),
|
|
}
|
|
}
|
|
|
|
#[test]
|
|
fn verifier_with_binding() {
|
|
let image = b"kernel with binding test";
|
|
let hash = sha3_256(image);
|
|
|
|
let header = KernelHeader {
|
|
kernel_magic: KERNEL_MAGIC,
|
|
header_version: 1,
|
|
arch: KernelArch::X86_64 as u8,
|
|
kernel_type: KernelType::MicroLinux as u8,
|
|
kernel_flags: 0,
|
|
min_memory_mb: 64,
|
|
entry_point: 0,
|
|
image_size: image.len() as u64,
|
|
compressed_size: image.len() as u64,
|
|
compression: 0,
|
|
api_transport: 0,
|
|
api_port: 0,
|
|
api_version: 1,
|
|
image_hash: hash,
|
|
build_id: [0; 16],
|
|
build_timestamp: 0,
|
|
vcpu_count: 0,
|
|
reserved_0: 0,
|
|
cmdline_offset: 256,
|
|
cmdline_length: 0,
|
|
reserved_1: 0,
|
|
};
|
|
let header_bytes = header.to_bytes();
|
|
|
|
let binding = KernelBinding {
|
|
manifest_root_hash: [0x11; 32],
|
|
policy_hash: [0x22; 32],
|
|
binding_version: 1,
|
|
min_runtime_version: 0,
|
|
_pad0: 0,
|
|
allowed_segment_mask: 0,
|
|
_reserved: [0; 48],
|
|
};
|
|
let binding_bytes = binding.to_bytes();
|
|
|
|
let (verified, decoded_binding) =
|
|
KernelVerifier::verify_with_binding(&header_bytes, &binding_bytes, image).unwrap();
|
|
assert_eq!(verified.arch, KernelArch::X86_64);
|
|
assert_eq!(decoded_binding.binding_version, 1);
|
|
assert_eq!(decoded_binding.manifest_root_hash, [0x11; 32]);
|
|
}
|
|
|
|
#[test]
|
|
fn build_kernel_header_fills_fields() {
|
|
let image_data = b"test kernel data for header building";
|
|
let hash = sha3_256(image_data);
|
|
|
|
let kernel = BuiltKernel {
|
|
bzimage: image_data.to_vec(),
|
|
initramfs: None,
|
|
config: KernelConfig {
|
|
cmdline: "console=ttyS0 root=/dev/vda".to_string(),
|
|
..Default::default()
|
|
},
|
|
image_hash: hash,
|
|
compressed_size: image_data.len() as u64,
|
|
};
|
|
|
|
let builder = KernelBuilder::new(KernelArch::X86_64).with_initramfs(&["sshd"]);
|
|
|
|
let header = build_kernel_header(&kernel, &builder, 8080);
|
|
|
|
assert_eq!(header.kernel_magic, KERNEL_MAGIC);
|
|
assert_eq!(header.header_version, 1);
|
|
assert_eq!(header.arch, KernelArch::X86_64 as u8);
|
|
assert_eq!(header.kernel_type, KernelType::MicroLinux as u8);
|
|
assert_eq!(header.image_size, image_data.len() as u64);
|
|
assert_eq!(header.image_hash, hash);
|
|
assert_eq!(header.api_port, 8080);
|
|
assert_eq!(header.min_memory_mb, 64);
|
|
assert_eq!(header.entry_point, 0x0020_0000);
|
|
assert_eq!(header.cmdline_length, 27); // "console=ttyS0 root=/dev/vda"
|
|
|
|
// Should include ADMIN_API flag because sshd is in services
|
|
assert!(header.kernel_flags & rvf_types::kernel::KERNEL_FLAG_HAS_ADMIN_API != 0);
|
|
}
|
|
|
|
#[test]
|
|
fn build_initramfs_via_builder() {
|
|
let builder = KernelBuilder::new(KernelArch::X86_64);
|
|
let result = builder.build_initramfs(&["sshd"], &[]).unwrap();
|
|
|
|
// Should be gzipped
|
|
assert_eq!(result[0], 0x1F);
|
|
assert_eq!(result[1], 0x8B);
|
|
assert!(result.len() > 100);
|
|
}
|
|
|
|
#[test]
|
|
fn error_display_formatting() {
|
|
let err = KernelError::ImageTooSmall {
|
|
size: 100,
|
|
min_size: 512,
|
|
};
|
|
let msg = format!("{err}");
|
|
assert!(msg.contains("100"));
|
|
assert!(msg.contains("512"));
|
|
|
|
let err2 = KernelError::HashMismatch {
|
|
expected: [0xAA; 32],
|
|
actual: [0xBB; 32],
|
|
};
|
|
let msg2 = format!("{err2}");
|
|
assert!(msg2.contains("aaaa"));
|
|
assert!(msg2.contains("bbbb"));
|
|
}
|
|
|
|
#[test]
|
|
fn kernel_config_default() {
|
|
let cfg = KernelConfig::default();
|
|
assert!(cfg.prebuilt_path.is_none());
|
|
assert!(cfg.docker_context.is_none());
|
|
assert_eq!(cfg.cmdline, "console=ttyS0 quiet");
|
|
assert_eq!(cfg.arch, KernelArch::X86_64);
|
|
assert!(!cfg.with_initramfs);
|
|
assert!(cfg.services.is_empty());
|
|
}
|
|
|
|
#[test]
|
|
fn from_builtin_minimal_produces_valid_bzimage() {
|
|
let kernel = KernelBuilder::from_builtin_minimal().unwrap();
|
|
let img = &kernel.bzimage;
|
|
|
|
// Must be 4096 bytes
|
|
assert_eq!(img.len(), 4096);
|
|
|
|
// Boot sector magic at 510-511
|
|
assert_eq!(img[0x1FE], 0x55);
|
|
assert_eq!(img[0x1FF], 0xAA);
|
|
|
|
// HdrS magic at 0x202 (little-endian: 0x53726448)
|
|
assert_eq!(img[0x202], 0x48); // 'H'
|
|
assert_eq!(img[0x203], 0x64); // 'd'
|
|
assert_eq!(img[0x204], 0x72); // 'r'
|
|
assert_eq!(img[0x205], 0x53); // 'S'
|
|
|
|
// Boot protocol version >= 2.00
|
|
let version = u16::from_le_bytes([img[0x206], img[0x207]]);
|
|
assert!(version >= 0x0200);
|
|
|
|
// Protected-mode entry stub at offset 0x400
|
|
assert_eq!(img[0x400], 0xFA); // CLI
|
|
assert_eq!(img[0x401], 0xF4); // HLT
|
|
|
|
// Hash is deterministic
|
|
assert_eq!(kernel.image_hash, sha3_256(img));
|
|
|
|
// from_prebuilt should accept this image when written to disk
|
|
let dir = tempfile::TempDir::new().unwrap();
|
|
let path = dir.path().join("builtin.bzImage");
|
|
std::fs::write(&path, img).unwrap();
|
|
let loaded = KernelBuilder::from_prebuilt(&path).unwrap();
|
|
assert_eq!(loaded.bzimage, kernel.bzimage);
|
|
}
|
|
|
|
#[test]
|
|
fn build_falls_back_to_builtin_without_docker() {
|
|
// build() should succeed even when Docker is not available,
|
|
// because it falls back to from_builtin_minimal().
|
|
let dir = tempfile::TempDir::new().unwrap();
|
|
let builder = KernelBuilder::new(KernelArch::X86_64);
|
|
let result = builder.build(dir.path());
|
|
// Should always succeed (either via Docker or fallback)
|
|
assert!(result.is_ok());
|
|
let kernel = result.unwrap();
|
|
assert!(!kernel.bzimage.is_empty());
|
|
// At minimum it must have the boot sector magic
|
|
assert_eq!(kernel.bzimage[0x1FE], 0x55);
|
|
assert_eq!(kernel.bzimage[0x1FF], 0xAA);
|
|
}
|
|
}
|