Implement supervised rootless network readiness

This commit is contained in:
ms2k 2026-07-15 23:26:37 +09:00
commit ba6a075839

View file

@ -0,0 +1,330 @@
use std::ffi::OsString;
use std::fs::File;
use std::os::fd::{AsFd, AsRawFd};
use std::path::{Path, PathBuf};
use std::process::ExitCode;
use std::time::{Duration, Instant};
use lazaret_core::codec::{decode, encode};
use lazaret_core::identity::{
ConfigurationFingerprint, CoordinatorId, DomainId, GenerationId, NetworkSidecarId,
};
use lazaret_core::network::{
DnsQueryExpectation, ReachabilityExpectation, ReadinessExpectation, accept_network_readiness,
derive_policy, validate_network_attestation,
};
use lazaret_core::records::{
AddressFamily, AddressFamilyDisposition, AddressFamilyDispositionValue, DefaultAction,
DerivedNetworkPolicyFields, HostProcessOwnershipSlot, IpAddress, IpNetwork,
NetworkReadinessAttestation, PolicyAction, PrefixRule, ProcessOwnershipCommitAck, Resolver,
};
use lazaret_linux::filesystem::{atomic_replace, require_write_sealed, sealed_memfd};
use lazaret_linux::process::{
ProcessOwnershipContext, TargetCommand, child_broker, current_process_identity,
dispatch_private_process_role, recover_process,
};
use lazaret_runtime_supervisor::network::{
DnsProbeTarget, NetworkAttestationContext, NetworkProbeRequest, TcpProbeTarget,
prepare_network, probe_current_network,
};
use rustix::io::{FdFlags, fcntl_setfd};
use rustix::process::Signal;
const CHILD_ROLE: &str = "--network-runtime-child";
const SKIP: u8 = 77;
fn main() -> ExitCode {
let arguments = std::env::args_os().skip(1).collect::<Vec<_>>();
if let Some(result) = dispatch_private_process_role(&arguments) {
return exit(result);
}
if arguments.first().and_then(|value| value.to_str()) == Some(CHILD_ROLE) {
return exit(run_child(&arguments[1..]));
}
match run_parent() {
Ok(()) => {
println!("PASS real rootless network namespace and supervised slirp4netns");
ExitCode::SUCCESS
}
Err(error) if prerequisite_failure(&error) => {
println!("SKIP real network runtime: {error}");
ExitCode::from(SKIP)
}
Err(error) => {
eprintln!("network runtime failed: {error}");
ExitCode::FAILURE
}
}
}
fn run_parent() -> std::io::Result<()> {
for executable in ["/usr/bin/slirp4netns", "/usr/bin/ip"] {
if !Path::new(executable).is_file() {
return Err(std::io::Error::new(
std::io::ErrorKind::NotFound,
format!("required executable is absent: {executable}"),
));
}
}
let directory = tempfile::tempdir()?;
let policy = policy()?;
let policy_file = sealed_memfd("network-runtime-policy", policy.canonical_bytes())?;
fcntl_setfd(policy_file.as_fd(), FdFlags::empty())?;
let verifier_executable = std::env::current_exe()?;
let target = TargetCommand::new(verifier_executable)
.argument(CHILD_ROLE)
.argument(directory.path())
.argument(policy_file.as_raw_fd().to_string())
.argument(hex(policy.digest().as_bytes()));
let parent = current_process_identity()?;
let runtime = child_broker().acquire(
parent,
ProcessOwnershipContext {
domain_id: DomainId::new([1; 32]),
generation_id: GenerationId::new(7),
coordinator_id: CoordinatorId::new([2; 32]),
slot: HostProcessOwnershipSlot::SandboxRuntimeSupervisor,
},
&target,
|_| Ok(()),
|staged| Ok(ProcessOwnershipCommitAck::v1(staged)),
)?;
let attestation_path = directory.path().join("attestation.postcard");
wait_for_path(&attestation_path, &runtime)?;
let attestation: NetworkReadinessAttestation = decode(&std::fs::read(&attestation_path)?)
.map_err(|error| std::io::Error::other(error.to_string()))?;
if attestation.runtime_supervisor != runtime.identity()
|| !attestation.observation.helper_ready
|| !attestation.observation.routes_attested
|| attestation.observation.observed_routes.len() < 3
{
return cleanup_runtime(runtime, std::io::Error::other("attestation is incomplete"));
}
let probe_path = directory.path().join("probe.postcard");
wait_for_path(&probe_path, &runtime)?;
let probe: lazaret_core::records::NetworkReachabilityProbe =
decode(&std::fs::read(&probe_path)?)
.map_err(|error| std::io::Error::other(error.to_string()))?;
let expectation = ReadinessExpectation {
domain_id: attestation.domain_id,
generation_id: attestation.generation_id,
configuration_fingerprint: attestation.configuration_fingerprint,
network_sidecar_id: attestation.network_sidecar_id,
enforcement_namespace: attestation.enforcement_namespace,
runtime_supervisor: &attestation.runtime_supervisor,
connectivity_helper: &attestation.connectivity_helper,
};
accept_network_readiness(
&policy,
&expectation,
attestation.clone(),
probe,
&reachability(),
)
.map_err(std::io::Error::other)?;
let mut mutated = attestation.clone();
mutated.derived_policy_digest = lazaret_core::identity::DerivedPolicyDigest::new([9; 32]);
if validate_network_attestation(&policy, &expectation, &mutated).is_ok() {
return cleanup_runtime(
runtime,
std::io::Error::other("mutated attestation was accepted"),
);
}
let helper = recover_process(attestation.connectivity_helper)?;
helper.send_signal(Signal::KILL)?;
wait_for_path(&directory.path().join("helper-lost"), &runtime)?;
runtime.send_signal(Signal::KILL)?;
child_broker().reap(runtime)
}
fn run_child(arguments: &[OsString]) -> std::io::Result<()> {
let directory = PathBuf::from(
arguments
.first()
.ok_or_else(|| std::io::Error::other("network child directory is absent"))?,
);
let policy_fd = arguments
.get(1)
.and_then(|value| value.to_str())
.and_then(|value| value.parse::<i32>().ok())
.filter(|value| *value >= 0)
.ok_or_else(|| std::io::Error::other("network child policy fd is invalid"))?;
let digest = parse_digest(
arguments
.get(2)
.ok_or_else(|| std::io::Error::other("network child digest is absent"))?,
)?;
let policy_file = File::open(format!("/proc/self/fd/{policy_fd}"))?;
require_write_sealed(&policy_file)?;
let runtime = current_process_identity()?;
let prepared = prepare_network(
&policy_file,
digest,
NetworkAttestationContext {
domain_id: DomainId::new([1; 32]),
generation_id: GenerationId::new(7),
configuration_fingerprint: ConfigurationFingerprint::new([3; 32]),
network_sidecar_id: NetworkSidecarId::new([4; 32]),
runtime_supervisor: runtime,
coordinator_id: CoordinatorId::new([2; 32]),
},
|_| Ok(()),
|staged| Ok(ProcessOwnershipCommitAck::v1(staged)),
)?;
let attestation = prepared.attestation().clone();
atomic_replace(
&directory.join("attestation.postcard"),
&encode(&attestation).map_err(std::io::Error::other)?,
)?;
let probe = probe_current_network(&probe_request(attestation.enforcement_namespace))?;
atomic_replace(
&directory.join("probe.postcard"),
&encode(&probe).map_err(std::io::Error::other)?,
)?;
loop {
if prepared.helper_exited()? {
prepared.reap_exited()?;
std::fs::write(directory.join("helper-lost"), b"lost")?;
loop {
std::thread::sleep(Duration::from_secs(1));
}
}
std::thread::sleep(Duration::from_millis(5));
}
}
fn policy() -> std::io::Result<lazaret_core::network::CanonicalDerivedNetworkPolicy> {
derive_policy(DerivedNetworkPolicyFields {
address_families: vec![
AddressFamilyDisposition {
family: AddressFamily::Ipv4,
disposition: AddressFamilyDispositionValue::Enabled,
},
AddressFamilyDisposition {
family: AddressFamily::Ipv6,
disposition: AddressFamilyDispositionValue::Disabled,
},
],
default_actions: vec![DefaultAction {
family: AddressFamily::Ipv4,
action: PolicyAction::Allow,
}],
prefix_rules: [
([10, 0, 0, 0], 8),
([172, 16, 0, 0], 12),
([192, 168, 0, 0], 16),
]
.into_iter()
.map(|(address, prefix_length)| PrefixRule {
family: AddressFamily::Ipv4,
network: IpNetwork {
address: IpAddress::V4(address),
prefix_length,
},
action: PolicyAction::Deny,
})
.collect(),
resolvers: vec![Resolver {
family: AddressFamily::Ipv4,
address: IpAddress::V4([10, 0, 2, 3]),
}],
})
.map_err(std::io::Error::other)
}
fn probe_request(namespace: lazaret_core::identity::NamespaceIdentity) -> NetworkProbeRequest {
NetworkProbeRequest {
domain_id: DomainId::new([1; 32]),
generation_id: GenerationId::new(7),
enforcement_namespace: namespace,
denied: vec![TcpProbeTarget {
address: IpAddress::V4([10, 1, 2, 3]),
port: 443,
}],
permitted: vec![TcpProbeTarget {
address: IpAddress::V4([1, 1, 1, 1]),
port: 443,
}],
dns: vec![DnsProbeTarget {
resolver: IpAddress::V4([10, 0, 2, 3]),
query_name: "example.com".into(),
}],
}
}
fn reachability() -> ReachabilityExpectation {
ReachabilityExpectation {
denied_destinations: vec![IpAddress::V4([10, 1, 2, 3])],
permitted_destinations: vec![IpAddress::V4([1, 1, 1, 1])],
dns_queries: vec![DnsQueryExpectation {
resolver: IpAddress::V4([10, 0, 2, 3]),
query_name: "example.com".into(),
}],
}
}
fn wait_for_path(
path: &Path,
process: &lazaret_linux::process::RetainedProcess,
) -> std::io::Result<()> {
let deadline = Instant::now() + Duration::from_secs(30);
while !path.exists() {
if process.has_exited()? {
return Err(std::io::Error::other(
"network runtime exited before evidence",
));
}
if Instant::now() >= deadline {
return Err(std::io::Error::other("network runtime evidence timed out"));
}
std::thread::sleep(Duration::from_millis(5));
}
Ok(())
}
fn cleanup_runtime<T>(
runtime: lazaret_linux::process::RetainedProcess,
error: std::io::Error,
) -> std::io::Result<T> {
let _ = runtime.send_signal(Signal::KILL);
let _ = child_broker().reap(runtime);
Err(error)
}
fn parse_digest(value: &OsString) -> std::io::Result<lazaret_core::identity::DerivedPolicyDigest> {
let value = value
.to_str()
.filter(|value| value.len() == 64 && value.bytes().all(|byte| byte.is_ascii_hexdigit()))
.ok_or_else(|| std::io::Error::other("network child digest is invalid"))?;
let mut bytes = [0_u8; 32];
for (index, byte) in bytes.iter_mut().enumerate() {
*byte = u8::from_str_radix(&value[index * 2..index * 2 + 2], 16)
.map_err(|_| std::io::Error::other("network child digest is invalid"))?;
}
Ok(lazaret_core::identity::DerivedPolicyDigest::new(bytes))
}
fn hex(bytes: &[u8]) -> String {
use std::fmt::Write as _;
bytes.iter().fold(String::new(), |mut output, byte| {
write!(output, "{byte:02x}").unwrap();
output
})
}
fn prerequisite_failure(error: &std::io::Error) -> bool {
matches!(
error.kind(),
std::io::ErrorKind::NotFound | std::io::ErrorKind::PermissionDenied
) || matches!(error.raw_os_error(), Some(1 | 13 | 95))
}
fn exit(result: std::io::Result<()>) -> ExitCode {
match result {
Ok(()) => ExitCode::SUCCESS,
Err(error) => {
eprintln!("network child failed: {error}");
ExitCode::FAILURE
}
}
}