ab/tsunagi
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Added windown support

Browse Source
This commit is contained in:
ab
2026-09-22 12:34:19 +03:00
parent 458051f47d
commit e735151d62
14 changed files with 1645 additions and 377 deletions
Download Patch File Download Diff File Expand all files Collapse all files
Cargo.lock
Generated
+1
View File
@@ -3832,6 +3832,7 @@ dependencies = [
"hkdf",
"hmac 0.13.0",
"iroh",
"netdev 0.45.1",
"netwatch",
"postcard",
"rand 0.10.3",
crates/tsunagi-cli/src/main.rs
+44 -25
View File
@@ -712,14 +712,14 @@ enum Observed {
/// Asks the agent, and falls back to the state store.
async fn observe(paths: &StoragePaths, socket: &std::path::Path) -> Observed {
let socket_present = socket.exists();
let socket_present = tsunagi::ipc::is_serving(socket).await;
let why = if socket_present {
match tsunagi::ipc::unix::request_status(socket).await {
match tsunagi::ipc::request_status(socket).await {
Ok(report) => return Observed::Agent(Box::new(report)),
Err(err) => format!("{err}"),
}
} else {
"no control socket for this state directory".to_string()
"no agent is serving this state directory".to_string()
};
// Read-only, and deliberately tolerant: a state directory that has never
@@ -876,7 +876,11 @@ fn dns_publisher() -> Arc<dyn tsunagi::dns::DnsPublisher> {
{
Arc::new(tsunagi::dns::publish::ResolvedPublisher::new())
}
#[cfg(not(target_os = "linux"))]
#[cfg(target_os = "windows")]
{
Arc::new(tsunagi::dns::publish::NrptPublisher::new())
}
#[cfg(not(any(target_os = "linux", target_os = "windows")))]
{
Arc::new(tsunagi::dns::publish::UnsupportedPublisher::new())
}
@@ -1212,7 +1216,7 @@ struct AgentControl {
paths: StoragePaths,
}
impl tsunagi::ipc::unix::ReportSource for AgentControl {
impl tsunagi::ipc::ReportSource for AgentControl {
fn report(&self) -> tsunagi::BoxFuture<'_, tsunagi::ipc::StatusReport> {
Box::pin(async move {
let dns = self.dns_state().await;
@@ -1531,9 +1535,9 @@ async fn join_network(
// The running agent, because a second `up` cannot have the directory
// and because this way the network starts at once instead of at the
// next restart.
if socket.exists() {
if tsunagi::ipc::is_serving(socket).await {
let report =
tsunagi::ipc::unix::join_network(socket, name.as_str(), secret.encode().as_str())
tsunagi::ipc::join_network(socket, name.as_str(), secret.encode().as_str())
.await?;
// The id in full either way: it is what every other command takes,
// and the shortened form in a report is for reading, not copying.
@@ -1618,7 +1622,7 @@ async fn join_network(
/// comes from the running agent, because without a peer to contact the
/// other side has nothing to go on.
async fn invite(socket: &std::path::Path, name: &NetworkName, secret: &NetworkSecret) {
let endpoint = tsunagi::ipc::unix::request_status(socket)
let endpoint = tsunagi::ipc::request_status(socket)
.await
.ok()
.map(|report| report.endpoint_id)
@@ -1726,8 +1730,8 @@ async fn set_active(
let id = network.network_id.to_string();
let name = network.name.clone();
if socket.exists() {
let report = tsunagi::ipc::unix::set_active(socket, &id, active).await?;
if tsunagi::ipc::is_serving(socket).await {
let report = tsunagi::ipc::set_active(socket, &id, active).await?;
match (report.active, report.changed) {
(false, true) => println!(
"stopped `{}` ({}); everything it has is kept",
@@ -1777,8 +1781,8 @@ async fn leave_network(
// The running agent does it, because only it can publish the release
// while its sessions are still up.
if socket.exists() {
let report = tsunagi::ipc::unix::leave_network(socket, &id).await?;
if tsunagi::ipc::is_serving(socket).await {
let report = tsunagi::ipc::leave_network(socket, &id).await?;
println!("left `{}` ({})", report.name, short(&id, 10));
match (report.announced, report.peers_told) {
(true, 0) => eprintln!(
@@ -1846,7 +1850,7 @@ fn forget_protocol_state(paths: &StoragePaths, network: tsunagi::NetworkId) {
async fn wipe(args: WipeArgs) -> Result<(), Box<dyn std::error::Error>> {
let paths = args.paths.resolve()?;
let socket = control_socket(&paths, args.control_socket.as_ref());
if socket.exists() {
if tsunagi::ipc::is_serving(&socket).await {
return Err(
"stop the agent first: a wipe removes the state it is using, and leaving a \
network properly needs it running anyway"
@@ -1883,8 +1887,9 @@ async fn wipe(args: WipeArgs) -> Result<(), Box<dyn std::error::Error>> {
}
let removed = tsunagi::storage::wipe(&paths)?;
// A socket file with nothing behind it is a leftover of the same kind.
if tokio::net::UnixStream::connect(&socket).await.is_err() {
// A socket file with nothing behind it is a leftover of the same kind. On
// Windows there is no socket file, so this only ever tidies a Unix one.
if !tsunagi::ipc::is_serving(&socket).await {
let _ = std::fs::remove_file(&socket);
}
println!("removed {} item(s):", removed.entries().count());
@@ -1918,8 +1923,8 @@ async fn dns_command(args: DnsArgs) -> Result<(), Box<dyn std::error::Error>> {
// The running agent, so it takes effect now; it stores the setting too,
// so the two can never say different things.
if socket.exists() {
let report = tsunagi::ipc::unix::set_dns(&socket, enable, port).await?;
if tsunagi::ipc::is_serving(&socket).await {
let report = tsunagi::ipc::set_dns(&socket, enable, port).await?;
match report {
Some(report) => {
println!(
@@ -2083,8 +2088,8 @@ async fn set_hostname(
socket: &std::path::Path,
name: &str,
) -> Result<(), Box<dyn std::error::Error>> {
if socket.exists() {
return match tsunagi::ipc::unix::set_hostname(socket, name).await {
if tsunagi::ipc::is_serving(socket).await {
return match tsunagi::ipc::set_hostname(socket, name).await {
Ok(accepted) => {
println!("{accepted}");
Ok(())
@@ -2128,7 +2133,7 @@ async fn rotate_key(
// The rotation writes, so it needs the directory to itself. Refused up
// front rather than after the lock fails, because what a lock failure
// says does not tell the reader what to do about it.
if socket.exists() {
if tsunagi::ipc::is_serving(socket).await {
return Err(
"stop the agent first: replacing the signing key rewrites state it is using".into(),
);
@@ -2741,7 +2746,12 @@ fn host_section() -> report::Section {
use tsunagi::overlay::{Privilege, probe_net_admin};
match probe_net_admin() {
Privilege::Available => {
host.push(Row::new(Health::Good, "privileges", "CAP_NET_ADMIN held"));
let held = if cfg!(target_os = "windows") {
"assumes an elevated process; creation reports if not"
} else {
"CAP_NET_ADMIN held"
};
host.push(Row::new(Health::Good, "privileges", held));
host.push(Row::new(
Health::Good,
"interface",
@@ -3339,7 +3349,7 @@ async fn up(args: UpArgs) -> Result<(), Box<dyn std::error::Error>> {
// answer to a question nobody asked.
Err(tsunagi::Error::StateLocked { path }) => {
let socket = control_socket(&paths, args.control_socket.as_ref());
if socket.exists() {
if tsunagi::ipc::is_serving(&socket).await {
return Err(format!(
"an agent is already running for {}, and one state directory is one \
agent — it is the device, not a network.\n\n\
@@ -3394,14 +3404,14 @@ async fn up(args: UpArgs) -> Result<(), Box<dyn std::error::Error>> {
let agent = agent.clone();
let plugin = wireguard.clone();
let dns = Arc::clone(&dns);
let source: Arc<dyn tsunagi::ipc::unix::ReportSource> = Arc::new(AgentControl {
let source: Arc<dyn tsunagi::ipc::ReportSource> = Arc::new(AgentControl {
agent,
plugin,
dns,
paths: paths.clone(),
});
let path = control_socket(&paths, args.control_socket.as_ref());
match tsunagi::ipc::unix::ControlSocket::bind(path, source).await {
match tsunagi::ipc::ControlSocket::bind(path, source).await {
Ok(socket) => {
println!(" control {}", socket.path().display());
Some(socket)
@@ -3643,11 +3653,20 @@ fn system_tun_factory() -> Result<Arc<dyn TunFactory>, Box<dyn std::error::Error
Ok(Arc::new(ManagedTunFactory::new(Arc::new(provisioner))))
}
/// The Wintun adapter, created and configured by the agent and removed when it
/// exits, the same as the Linux one.
#[cfg(target_os = "windows")]
fn system_tun_factory() -> Result<Arc<dyn TunFactory>, Box<dyn std::error::Error>> {
use tsunagi::overlay::{ManagedTunFactory, WintunProvisioner};
let provisioner = WintunProvisioner::new()?;
Ok(Arc::new(ManagedTunFactory::new(Arc::new(provisioner))))
}
/// There is no provisioner for this platform yet.
///
/// Refused here rather than at the first packet, and with the one thing that
/// does work on every platform named.
#[cfg(not(target_os = "linux"))]
#[cfg(not(any(target_os = "linux", target_os = "windows")))]
fn system_tun_factory() -> Result<Arc<dyn TunFactory>, Box<dyn std::error::Error>> {
Err(format!(
"managing the overlay interface is not implemented on {} yet. \
crates/tsunagi-wg-quic/tests/local_control.rs
+9 -9
View File
@@ -12,7 +12,7 @@ use std::time::Duration;
use tempfile::TempDir;
use tsunagi::dataplane::IpPlugin;
use tsunagi::discovery::SharedMemoryDiscovery;
use tsunagi::ipc::unix::{ControlSocket, request_status};
use tsunagi::ipc::{ControlSocket, request_status};
use tsunagi::ipc::{StatusReport, control_socket_path};
use tsunagi::overlay::MemoryTunFactory;
use tsunagi::testing::{config_with, network, wait_for_peers, wait_until};
@@ -20,7 +20,7 @@ use tsunagi::{Agent, BoxFuture};
use tsunagi_wg_quic::{WireguardConfig, WireguardPlugin};
/// Builds the report the way the binary does, from the agent plus the plugin.
fn source(agent: Agent, plugin: Arc<WireguardPlugin>) -> Arc<dyn tsunagi::ipc::unix::ReportSource> {
fn source(agent: Agent, plugin: Arc<WireguardPlugin>) -> Arc<dyn tsunagi::ipc::ReportSource> {
Arc::new(move || -> BoxFuture<'static, StatusReport> {
let agent = agent.clone();
let plugin = Arc::clone(&plugin);
@@ -186,7 +186,7 @@ async fn a_leftover_socket_file_is_replaced_but_a_live_one_is_not() {
let dir = TempDir::new().unwrap();
let path = dir.path().join("agent.sock");
let empty: Arc<dyn tsunagi::ipc::unix::ReportSource> =
let empty: Arc<dyn tsunagi::ipc::ReportSource> =
Arc::new(|| -> BoxFuture<'static, StatusReport> {
Box::pin(async { StatusReport::default() })
});
@@ -238,7 +238,7 @@ fn the_socket_path_is_derived_and_short_enough() {
#[derive(Debug)]
struct Control(Agent);
impl tsunagi::ipc::unix::ReportSource for Control {
impl tsunagi::ipc::ReportSource for Control {
fn report(&self) -> BoxFuture<'_, StatusReport> {
Box::pin(async move { StatusReport::default() })
}
@@ -324,7 +324,7 @@ async fn a_client_can_leave_a_network_through_the_running_agent() {
.await
.unwrap();
let report = tsunagi::ipc::unix::leave_network(&socket_path, &network_id.to_string())
let report = tsunagi::ipc::leave_network(&socket_path, &network_id.to_string())
.await
.unwrap();
assert_eq!(report.name, name.as_str());
@@ -333,7 +333,7 @@ async fn a_client_can_leave_a_network_through_the_running_agent() {
assert!(agent.list_networks().await.unwrap().is_empty());
// Asking again names the state it is in rather than failing obscurely.
let err = tsunagi::ipc::unix::leave_network(&socket_path, &network_id.to_string())
let err = tsunagi::ipc::leave_network(&socket_path, &network_id.to_string())
.await
.unwrap_err();
assert!(err.to_string().contains("not a network"), "{err}");
@@ -364,7 +364,7 @@ async fn a_client_can_add_a_network_to_a_running_agent() {
.await
.unwrap();
let report = tsunagi::ipc::unix::join_network(
let report = tsunagi::ipc::join_network(
&socket_path,
second.as_str(),
second_secret.encode().as_str(),
@@ -382,7 +382,7 @@ async fn a_client_can_add_a_network_to_a_running_agent() {
assert!(agent.network_status(joined).await.is_ok());
// Joining the same one again is not an error, and says which it was.
let again = tsunagi::ipc::unix::join_network(
let again = tsunagi::ipc::join_network(
&socket_path,
second.as_str(),
second_secret.encode().as_str(),
@@ -393,7 +393,7 @@ async fn a_client_can_add_a_network_to_a_running_agent() {
assert_eq!(again.network_id, report.network_id);
// A secret that is not one is refused rather than stored.
let err = tsunagi::ipc::unix::join_network(&socket_path, "rubbish", "not-a-secret")
let err = tsunagi::ipc::join_network(&socket_path, "rubbish", "not-a-secret")
.await
.unwrap_err();
assert!(!err.to_string().is_empty());
crates/tsunagi/Cargo.toml
+28 -6
View File
@@ -12,11 +12,21 @@ repository.workspace = true
[features]
default = []
# A real TUN device, so a plugin can carry actual IP traffic. Needs
# CAP_NET_ADMIN at run time; without it the in-memory device serves tests.
tun-device = ["dep:tun", "dep:rtnetlink", "dep:caps", "dep:futures-util"]
# Telling the operating system where to send its DNS questions. Linux only
# for now; the zone and the server work without it.
# A real TUN device, so a plugin can carry actual IP traffic. On Linux it
# needs CAP_NET_ADMIN; on Windows the process must run elevated and
# `wintun.dll` must be reachable. Without either the in-memory device serves
# tests. The platform-specific dependencies are declared per target, so
# enabling this only pulls what the target it is built for actually uses.
tun-device = [
"dep:tun",
"dep:rtnetlink",
"dep:caps",
"dep:futures-util",
"dep:netdev",
]
# Telling the operating system where to send its DNS questions. systemd-resolved
# on Linux, the Name Resolution Policy Table on Windows; the zone and the
# server work without it either way.
dns-publish = ["dep:zbus"]
# The test harness in `testing`, for this crate's own tests and for a
# protocol crate's. Not on by default: it is only of use to a test.
@@ -24,7 +34,9 @@ testing = ["dep:tempfile", "dep:tracing-subscriber"]
[dependencies]
iroh.workspace = true
tokio.workspace = true
# `net` for the local control interface: a Unix socket on Unix, a named pipe
# on Windows. Both live behind the same `net` feature.
tokio = { workspace = true, features = ["net"] }
serde.workspace = true
postcard.workspace = true
bytes.workspace = true
@@ -69,6 +81,16 @@ zbus = { version = "5.19", default-features = false, features = ["tokio"], optio
caps = { version = "0.5", optional = true }
futures-util = { version = "0.3", default-features = false, optional = true }
# Windows-only interface provisioning. The Wintun adapter itself is created
# and driven through the `tun` dependency, whose safe wrapper is the only way
# in — loading `wintun.dll` is an `unsafe` call this crate forbids. `netdev`
# (already in the tree through `netwatch`) reads the interface table through a
# safe wrapper, which is how the provisioner observes an adapter by name
# before deciding what to change. Creating an adapter needs the process to be
# elevated and `wintun.dll` to be reachable at run time.
[target.'cfg(target_os = "windows")'.dependencies]
netdev = { version = "0.45", optional = true }
[dev-dependencies]
# Its own tests use the harness it publishes.
tsunagi = { path = ".", features = ["testing"] }
crates/tsunagi/src/dns/publish/mod.rs
+9
View File
@@ -23,6 +23,11 @@ mod resolved;
#[cfg(all(feature = "dns-publish", target_os = "linux"))]
pub use resolved::ResolvedPublisher;
#[cfg(all(feature = "dns-publish", target_os = "windows"))]
mod windows;
#[cfg(all(feature = "dns-publish", target_os = "windows"))]
pub use windows::NrptPublisher;
mod unsupported;
pub use unsupported::UnsupportedPublisher;
@@ -143,6 +148,10 @@ pub fn interface_index(name: &str) -> Option<u32> {
.ok()
}
/// The kernel's index for an interface.
///
/// Only the systemd-resolved publisher needs one, so off Linux there is
/// nothing to look up and this is always `None`.
#[cfg(not(target_os = "linux"))]
pub fn interface_index(_name: &str) -> Option<u32> {
None
crates/tsunagi/src/dns/publish/windows.rs
+296
View File
@@ -0,0 +1,296 @@
//! Telling the Windows DNS client to send some questions here, through the
//! Name Resolution Policy Table.
//!
//! The NRPT is how Windows does split DNS: a rule says "names under this
//! suffix are resolved by these servers", and names outside every rule are
//! resolved the ordinary way. That is exactly the contract of [`Published`] —
//! route these suffixes here and claim nothing else — so one NRPT rule per
//! suffix is the whole of it. The rules are keyed by namespace, not by
//! interface, so the interface name in [`Published`] is not needed here.
//!
//! # Why PowerShell
//!
//! The NRPT lives in the registry, but a rule only takes effect once the DNS
//! client is told to reload its policy, and that notification is an RPC with
//! no safe wrapper this crate may call — it forbids `unsafe`. The
//! `DnsClient` PowerShell module does the write *and* the reload, so it is
//! used by absolute path from `%SystemRoot%`. Every value passed to it is one
//! this agent produced: the suffixes are validated zone names (letters,
//! digits, `-`, `_`, `.` only) and the servers are addresses it is listening
//! on. They are still single-quoted and escaped when built into the script,
//! so nothing could be read as PowerShell rather than as data.
//!
//! # The port
//!
//! The Windows DNS client always asks on port 53; it cannot be told another.
//! So a server on a different port cannot be reached this way, and rather than
//! configure a rule that points at nothing, this says so — the same honest
//! failure the systemd-resolved path gives for an old resolver with no port.
//!
//! # Privilege
//!
//! Writing an NRPT rule needs an elevated process. An ordinary user is
//! refused, which is reported as its own kind of error because the answer to
//! it — run elevated, or as a service — differs from "this is not Windows".
use std::collections::BTreeSet;
use std::net::IpAddr;
use std::sync::Mutex;
use crate::BoxFuture;
use super::{DnsPublisher, PublishError, Published};
/// The port the Windows DNS client is fixed to.
const DNS_PORT: u16 = 53;
/// Configures the Name Resolution Policy Table through PowerShell.
#[derive(Debug, Default)]
pub struct NrptPublisher {
/// The namespaces last configured, so shutdown knows what to undo.
applied: Mutex<Vec<String>>,
}
impl NrptPublisher {
/// Creates the publisher. Nothing is contacted until [`Self::apply`].
pub fn new() -> Self {
Self::default()
}
}
/// A suffix as the NRPT wants it: a leading dot means "this and everything
/// under it".
fn namespace(domain: &str) -> String {
let trimmed = domain.trim_matches('.');
format!(".{trimmed}")
}
/// A PowerShell single-quoted literal, with any embedded quote doubled.
fn ps_literal(value: &str) -> String {
format!("'{}'", value.replace('\'', "''"))
}
/// A PowerShell array literal, `@('a','b')`, or `@()` when empty.
fn ps_array(values: &[String]) -> String {
let items: Vec<String> = values.iter().map(|value| ps_literal(value)).collect();
format!("@({})", items.join(","))
}
/// The script that clears our rules for these namespaces and then adds them.
fn apply_script(namespaces: &[String], servers: &[String]) -> String {
format!(
"$ErrorActionPreference = 'Stop'\n\
$ns = {ns}\n\
$srv = {srv}\n\
foreach ($n in $ns) {{ Get-DnsClientNrptRule | Where-Object {{ $_.Namespace -eq $n }} | \
ForEach-Object {{ Remove-DnsClientNrptRule -Name $_.Name -Force }} }}\n\
foreach ($n in $ns) {{ Add-DnsClientNrptRule -Namespace $n -NameServers $srv }}\n",
ns = ps_array(namespaces),
srv = ps_array(servers),
)
}
/// The script that clears our rules for these namespaces.
fn revert_script(namespaces: &[String]) -> String {
format!(
"$ErrorActionPreference = 'Stop'\n\
$ns = {ns}\n\
foreach ($n in $ns) {{ Get-DnsClientNrptRule | Where-Object {{ $_.Namespace -eq $n }} | \
ForEach-Object {{ Remove-DnsClientNrptRule -Name $_.Name -Force }} }}\n",
ns = ps_array(namespaces),
)
}
/// Turns what PowerShell said on failure into the kind of failure it is.
fn classify(text: &str) -> PublishError {
let lower = text.to_ascii_lowercase();
if lower.contains("access is denied")
|| lower.contains("requires elevation")
|| lower.contains("run as administrator")
|| lower.contains("administrator privilege")
|| lower.contains("permissiondenied")
{
PublishError::Refused(format!("the Windows DNS client refused the change: {text}"))
} else if lower.contains("is not recognized")
|| lower.contains("commandnotfoundexception")
|| lower.contains("not recognized as the name of a cmdlet")
{
PublishError::Unavailable(format!(
"the DnsClient PowerShell module is not available: {text}"
))
} else {
PublishError::Failed(format!("the Windows DNS client failed the change: {text}"))
}
}
/// Runs a PowerShell script from `%SystemRoot%` and maps a failure to a
/// [`PublishError`].
async fn powershell(script: String) -> Result<(), PublishError> {
let program = powershell_path();
let output = tokio::task::spawn_blocking(move || {
std::process::Command::new(program)
.args([
"-NoProfile",
"-NonInteractive",
"-ExecutionPolicy",
"Bypass",
"-Command",
&script,
])
.output()
})
.await
.map_err(|err| PublishError::Failed(format!("could not run PowerShell: {err}")))?
.map_err(|err| PublishError::Unavailable(format!("could not run PowerShell: {err}")))?;
if output.status.success() {
return Ok(());
}
let stderr = String::from_utf8_lossy(&output.stderr);
let text = if stderr.trim().is_empty() {
String::from_utf8_lossy(&output.stdout).trim().to_string()
} else {
stderr.trim().to_string()
};
Err(classify(if text.is_empty() { "no output" } else { &text }))
}
/// The absolute path to Windows PowerShell, so nothing on `PATH` can stand in
/// for it.
fn powershell_path() -> std::path::PathBuf {
let root = std::env::var_os("SystemRoot").unwrap_or_else(|| r"C:\Windows".into());
std::path::Path::new(&root)
.join("System32")
.join("WindowsPowerShell")
.join("v1.0")
.join("powershell.exe")
}
impl DnsPublisher for NrptPublisher {
fn name(&self) -> &str {
"windows-nrpt"
}
fn apply<'a>(&'a self, published: &'a Published) -> BoxFuture<'a, Result<(), PublishError>> {
Box::pin(async move {
if published.domains.is_empty() {
return Err(PublishError::Unavailable(
"there are no suffixes to route, so there is no rule to write".to_string(),
));
}
// Windows can only ask on port 53, so a server anywhere else is
// unreachable this way. Keep the ones it can use.
let servers: BTreeSet<IpAddr> = published
.servers
.iter()
.filter(|server| server.port() == DNS_PORT)
.map(|server| server.ip())
.collect();
if servers.is_empty() {
let elsewhere = published
.servers
.iter()
.map(|server| server.to_string())
.collect::<Vec<_>>()
.join(", ");
return Err(PublishError::Unavailable(format!(
"the Windows DNS client only asks on port {DNS_PORT}, and the server is on \
{elsewhere}. Run the server on port {DNS_PORT}, or point your resolver at it \
yourself."
)));
}
let namespaces: Vec<String> =
published.domains.iter().map(|d| namespace(d)).collect();
let servers: Vec<String> = servers.iter().map(|ip| ip.to_string()).collect();
powershell(apply_script(&namespaces, &servers)).await?;
match self.applied.lock() {
Ok(mut guard) => *guard = namespaces,
Err(poisoned) => *poisoned.into_inner() = namespaces,
}
Ok(())
})
}
fn revert(&self) -> BoxFuture<'_, Result<(), PublishError>> {
Box::pin(async move {
let namespaces = match self.applied.lock() {
Ok(mut guard) => std::mem::take(&mut *guard),
Err(poisoned) => std::mem::take(&mut *poisoned.into_inner()),
};
if namespaces.is_empty() {
return Ok(());
}
powershell(revert_script(&namespaces)).await
})
}
}
#[cfg(test)]
mod tests {
#![allow(clippy::unwrap_used, clippy::expect_used, clippy::panic)]
use super::*;
use std::net::SocketAddr;
#[test]
fn a_suffix_gets_a_leading_dot() {
assert_eq!(namespace("lab"), ".lab");
assert_eq!(namespace(".lab"), ".lab");
assert_eq!(namespace("a.b"), ".a.b");
}
#[test]
fn a_quote_in_a_value_cannot_escape_the_literal() {
// Zone names never contain a quote, but the escaping is what makes
// that a guarantee rather than a hope.
assert_eq!(ps_literal("a'b"), "'a''b'");
assert_eq!(ps_array(&["x".into(), "y".into()]), "@('x','y')");
assert_eq!(ps_array(&[]), "@()");
}
#[test]
fn the_apply_script_removes_before_it_adds() {
let script = apply_script(&[".lab".into()], &["10.13.37.69".into()]);
let remove = script.find("Remove-DnsClientNrptRule").unwrap();
let add = script.find("Add-DnsClientNrptRule").unwrap();
assert!(remove < add, "a stale rule must go before the new one:\n{script}");
assert!(script.contains("@('.lab')"));
assert!(script.contains("@('10.13.37.69')"));
}
#[test]
fn an_access_denied_is_a_refusal_a_missing_cmdlet_is_unavailable() {
assert!(matches!(
classify("Access is denied"),
PublishError::Refused(_)
));
assert!(matches!(
classify("The term 'Add-DnsClientNrptRule' is not recognized"),
PublishError::Unavailable(_)
));
assert!(matches!(classify("something else"), PublishError::Failed(_)));
}
#[tokio::test]
async fn a_server_only_on_a_nonstandard_port_is_unavailable_not_a_failure() {
// Nothing is run: Windows cannot ask there, and saying so is the
// honest answer without touching the DNS client.
let publisher = NrptPublisher::new();
let published = Published {
interface: "tsun0".into(),
servers: vec![SocketAddr::from(([10, 13, 37, 69], 5354))],
domains: vec!["lab".into()],
};
let err = publisher.apply(&published).await.unwrap_err();
assert!(matches!(err, PublishError::Unavailable(_)), "{err}");
}
#[tokio::test]
async fn reverting_without_having_applied_does_nothing_and_succeeds() {
NrptPublisher::new().revert().await.unwrap();
}
}
crates/tsunagi/src/ipc/mod.rs
+356
View File
@@ -27,11 +27,33 @@
#[cfg(unix)]
pub mod unix;
#[cfg(windows)]
pub mod windows;
// The one transport this build serves on. The two adapters expose the same
// items, so the rest of the crate — and the client wrappers below — name the
// transport through this alias and never a platform directly.
#[cfg(unix)]
use unix as transport;
#[cfg(windows)]
use windows as transport;
/// Serves the local control interface on this platform's transport.
///
/// A Unix socket on Unix, a named pipe on Windows; the same API either way.
#[cfg(any(unix, windows))]
pub use transport::ControlSocket;
use std::path::{Path, PathBuf};
use std::sync::Arc;
use std::time::Duration;
use serde::{Deserialize, Serialize};
use sha2::{Digest, Sha256};
use tokio::io::{AsyncRead, AsyncReadExt, AsyncWrite, AsyncWriteExt};
use crate::BoxFuture;
use crate::error::{Error, Result};
/// Largest accepted local control message.
pub const MAX_MESSAGE_LEN: usize = 1024 * 1024;
@@ -382,3 +404,337 @@ impl OverlayPeerReport {
self.handshake_secs_ago.is_some()
}
}
// ---------------------------------------------------------------------------
// The transport-agnostic half of the local control interface.
//
// Everything below is the same on every platform: the request/response
// framing, the dispatch of a request onto a [`ReportSource`], and the client
// wrappers that ask one question and read one answer. Only the listener and
// the stream differ, and those live in the per-platform `unix` and `windows`
// adapters. Each adapter drives the shared [`serve_connection`] for its
// accepted streams and offers a `connect`/`is_serving` for the client side,
// so the logic here is written once.
// ---------------------------------------------------------------------------
/// Builds the report that answers a status request, and applies the changes a
/// client asks for.
///
/// Supplied by the caller, because only the caller knows which plugins are
/// running and what they can report or change. That is what keeps this module
/// free of any knowledge of them.
pub trait ReportSource: Send + Sync + 'static {
/// Produces a fresh report.
fn report(&self) -> BoxFuture<'_, StatusReport>;
/// Changes the name the agent answers to, returning the accepted form.
///
/// Defaulted to a refusal so that a source which only reports — the
/// closure impl below, and every test that uses it — stays valid and
/// says plainly that it cannot do this, rather than appearing to.
fn set_hostname(
&self,
_hostname: String,
) -> BoxFuture<'_, std::result::Result<String, String>> {
Box::pin(async move { Err("this agent cannot change its hostname".to_string()) })
}
/// Leaves a network, publishing a release first.
///
/// Defaulted to a refusal for the same reason as the above: a source
/// that only reports says so plainly rather than appearing to do it.
fn leave(&self, _network_id: String) -> BoxFuture<'_, std::result::Result<LeftReport, String>> {
Box::pin(async move { Err("this agent cannot leave a network".to_string()) })
}
/// Joins a network, or starts one that is configured and not running.
///
/// Defaulted to a refusal, like the others: a source that only reports
/// says so rather than appearing to have done it.
fn join(
&self,
_name: String,
_secret: String,
) -> BoxFuture<'_, std::result::Result<JoinedReport, String>> {
Box::pin(async move { Err("this agent cannot join a network".to_string()) })
}
/// Stops serving a network, or starts serving it again.
///
/// Defaulted to a refusal, like the others.
fn set_active(
&self,
_network_id: String,
_active: bool,
) -> BoxFuture<'_, std::result::Result<ActiveReport, String>> {
Box::pin(async move { Err("this agent cannot stop or start a network".to_string()) })
}
/// Turns the local resolver on or off while the agent runs.
///
/// Defaulted to a refusal, like the others.
fn set_dns(
&self,
_enable: bool,
_port: Option<u16>,
) -> BoxFuture<'_, std::result::Result<Option<DnsReport>, String>> {
Box::pin(async move { Err("this agent cannot serve DNS".to_string()) })
}
}
impl<F> ReportSource for F
where
F: Fn() -> BoxFuture<'static, StatusReport> + Send + Sync + 'static,
{
fn report(&self) -> BoxFuture<'_, StatusReport> {
(self)()
}
}
/// How long either end waits for the other.
///
/// A local answer comes from memory, so anything this slow means the agent is
/// wedged rather than busy. Saying so beats waiting: unbounded, one wedged
/// runtime leaves `tsunagi status` hanging with nothing on screen and no way
/// out but Ctrl-C.
pub const EXCHANGE_TIMEOUT: Duration = Duration::from_secs(5);
/// Marks the wire format of the local control interface.
///
/// `b"TSN"` followed by the version, so a mismatch is recognised as one
/// instead of being read as a length. The encoding is postcard, which is not
/// self-describing: adding a field to a report changes how the bytes parse,
/// and without this a client one build ahead of its agent reports something
/// like "Found an Option discriminant that wasn't 0 or 1" — which says
/// nothing about the actual problem, that the two are different builds.
///
/// Bump it whenever [`Request`], [`Response`] or anything they contain
/// changes shape.
pub const CONTROL_PROTOCOL: u32 = u32::from_be_bytes([b'T', b'S', b'N', 13]);
/// Reads one request off an accepted stream, answers it, writes the response.
///
/// The per-platform adapters call this for every connection they accept, so
/// the request handling is identical on every transport.
pub(crate) async fn serve_connection<S>(mut stream: S, source: Arc<dyn ReportSource>) -> Result<()>
where
S: AsyncRead + AsyncWrite + Unpin,
{
// Bounded, so a connection that sends nothing cannot hold a task open.
// Only the wait for the request: building the report afterwards takes as
// long as it takes, and cutting it off would answer a live client with a
// closed socket.
let request: Request =
match tokio::time::timeout(EXCHANGE_TIMEOUT, read_message(&mut stream)).await {
Ok(request) => request?,
Err(_) => {
return Err(Error::Timeout {
what: "a local control connection".to_string(),
});
}
};
let response = match request {
Request::Status => Response::Status(Box::new(source.report().await)),
Request::SetHostname(hostname) => match source.set_hostname(hostname).await {
Ok(accepted) => Response::Hostname(accepted),
Err(reason) => Response::Error(reason),
},
Request::Leave(network_id) => match source.leave(network_id).await {
Ok(report) => Response::Left(report),
Err(reason) => Response::Error(reason),
},
Request::Join { name, secret } => match source.join(name, secret).await {
Ok(report) => Response::Joined(report),
Err(reason) => Response::Error(reason),
},
Request::SetActive { network_id, active } => {
match source.set_active(network_id, active).await {
Ok(report) => Response::Active(report),
Err(reason) => Response::Error(reason),
}
}
Request::Dns { enable, port } => match source.set_dns(enable, port).await {
Ok(report) => Response::Dns(report),
Err(reason) => Response::Error(reason),
},
};
write_message(&mut stream, &response).await
}
/// Connects, sends one request and reads the answer, all within `within`.
///
/// The bound covers the whole exchange rather than each read: an agent that
/// answers the header and then stops is as stuck as one that never answers.
async fn exchange(path: &Path, request: &Request, within: Duration) -> Result<Response> {
let attempt = async {
let mut stream = transport::connect(path).await?;
write_message(&mut stream, request).await?;
read_message::<Response, _>(&mut stream).await
};
match tokio::time::timeout(within, attempt).await {
Ok(result) => result,
Err(_) => Err(Error::Timeout {
what: format!("the agent at {}", path.display()),
}),
}
}
/// Whether an agent is serving the control interface at `path`.
///
/// Used to tell a running agent from a leftover: on Unix a socket file with
/// nothing behind it, on Windows nothing at all.
pub async fn is_serving(path: impl AsRef<Path>) -> bool {
transport::probe(path.as_ref()).await
}
/// Asks a running agent for its status.
pub async fn request_status(path: impl AsRef<Path>) -> Result<StatusReport> {
let path = path.as_ref();
match exchange(path, &Request::Status, EXCHANGE_TIMEOUT).await? {
Response::Status(report) => Ok(*report),
Response::Error(reason) => Err(Error::Storage(reason)),
other => Err(Error::Storage(format!("unexpected answer: {other:?}"))),
}
}
/// Asks a running agent to answer to a different name.
///
/// Returns the name it accepted, which is the canonical form of what was
/// asked for and may differ from it.
pub async fn set_hostname(path: impl AsRef<Path>, hostname: &str) -> Result<String> {
let path = path.as_ref();
let request = Request::SetHostname(hostname.to_string());
match exchange(path, &request, EXCHANGE_TIMEOUT).await? {
Response::Hostname(accepted) => Ok(accepted),
Response::Error(reason) => Err(Error::Storage(reason)),
other => Err(Error::Storage(format!("unexpected answer: {other:?}"))),
}
}
/// Asks a running agent to leave a network.
///
/// The agent publishes the release and removes the network; this only
/// carries the request and the outcome.
pub async fn leave_network(path: impl AsRef<Path>, network_id: &str) -> Result<LeftReport> {
let path = path.as_ref();
let request = Request::Leave(network_id.to_string());
match exchange(path, &request, EXCHANGE_TIMEOUT).await? {
Response::Left(report) => Ok(report),
Response::Error(reason) => Err(Error::Storage(reason)),
other => Err(Error::Storage(format!("unexpected answer: {other:?}"))),
}
}
/// Asks a running agent to join a network.
///
/// The one way to add a network to an agent that is already up: the state
/// directory belongs to one live agent, so a second `up` cannot.
pub async fn join_network(
path: impl AsRef<Path>,
name: &str,
secret: &str,
) -> Result<JoinedReport> {
let path = path.as_ref();
let request = Request::Join {
name: name.to_string(),
secret: secret.to_string(),
};
match exchange(path, &request, EXCHANGE_TIMEOUT).await? {
Response::Joined(report) => Ok(report),
Response::Error(reason) => Err(Error::Storage(reason)),
other => Err(Error::Storage(format!("unexpected answer: {other:?}"))),
}
}
/// Asks a running agent to stop serving a network, or to serve it again.
pub async fn set_active(
path: impl AsRef<Path>,
network_id: &str,
active: bool,
) -> Result<ActiveReport> {
let path = path.as_ref();
let request = Request::SetActive {
network_id: network_id.to_string(),
active,
};
match exchange(path, &request, EXCHANGE_TIMEOUT).await? {
Response::Active(report) => Ok(report),
Response::Error(reason) => Err(Error::Storage(reason)),
other => Err(Error::Storage(format!("unexpected answer: {other:?}"))),
}
}
/// Turns the running agent's local resolver on or off.
pub async fn set_dns(
path: impl AsRef<Path>,
enable: bool,
port: Option<u16>,
) -> Result<Option<DnsReport>> {
let path = path.as_ref();
match exchange(path, &Request::Dns { enable, port }, EXCHANGE_TIMEOUT).await? {
Response::Dns(report) => Ok(report),
Response::Error(reason) => Err(Error::Storage(reason)),
other => Err(Error::Storage(format!("unexpected answer: {other:?}"))),
}
}
pub(crate) async fn write_message<S, T>(stream: &mut S, value: &T) -> Result<()>
where
S: AsyncWrite + Unpin,
T: serde::Serialize,
{
let encoded = postcard::to_stdvec(value)
.map_err(|err| Error::Storage(format!("cannot encode a control message: {err}")))?;
if encoded.len() > MAX_MESSAGE_LEN {
return Err(Error::Storage("control message is too large".into()));
}
let len = encoded.len() as u32;
stream
.write_all(&CONTROL_PROTOCOL.to_be_bytes())
.await
.map_err(io_error)?;
stream
.write_all(&len.to_be_bytes())
.await
.map_err(io_error)?;
stream.write_all(&encoded).await.map_err(io_error)?;
stream.flush().await.map_err(io_error)
}
pub(crate) async fn read_message<T, S>(stream: &mut S) -> Result<T>
where
T: for<'de> serde::Deserialize<'de>,
S: AsyncRead + Unpin,
{
let mut header = [0u8; 4];
stream.read_exact(&mut header).await.map_err(io_error)?;
let version = u32::from_be_bytes(header);
if version != CONTROL_PROTOCOL {
return Err(Error::Storage(format!(
"the other end speaks control protocol {version:#010x} and this build speaks \
{CONTROL_PROTOCOL:#010x}; they are different builds of tsunagi, so restart the \
agent with the binary you are running now"
)));
}
stream.read_exact(&mut header).await.map_err(io_error)?;
let len = u32::from_be_bytes(header) as usize;
// Checked before allocating, exactly as on the network.
if len > MAX_MESSAGE_LEN {
return Err(Error::Storage(format!(
"control message of {len} bytes exceeds the {MAX_MESSAGE_LEN} byte limit"
)));
}
let mut payload = vec![0u8; len];
stream.read_exact(&mut payload).await.map_err(io_error)?;
postcard::from_bytes(&payload)
.map_err(|err| Error::Storage(format!("cannot decode a control message: {err}")))
}
pub(crate) fn io_error(source: std::io::Error) -> Error {
Error::Io {
path: PathBuf::from("<local control socket>"),
source,
}
}
crates/tsunagi/src/ipc/unix.rs
+28 -314
View File
@@ -1,99 +1,31 @@
//! A Unix socket adapter for the local control interface.
//!
//! One of possibly several adapters; see [`super`]. It serves exactly the
//! requests in [`Request`] and nothing else, and it is reachable only by a
//! process that can open a file inside the agent's owner-only state
//! directory.
//! One of the per-platform adapters; see [`super`]. It provides only what is
//! particular to a Unix socket — binding a listener, connecting a client, and
//! the owner-only permissions — and hands every accepted connection to the
//! shared [`serve_connection`](super::serve_connection). The request framing,
//! the dispatch and the client wrappers are the same on every platform and
//! live in [`super`], re-exported here so `ipc::unix::request_status` and its
//! siblings keep resolving.
//!
//! It is reachable only by a process that can open a file inside the agent's
//! owner-only state directory, and the socket itself is created mode `0600`.
use std::path::{Path, PathBuf};
use std::sync::Arc;
use std::time::Duration;
use tokio::io::{AsyncReadExt, AsyncWriteExt};
use tokio::net::{UnixListener, UnixStream};
use tokio::task::JoinHandle;
use crate::BoxFuture;
use crate::error::{Error, Result};
use super::{
ActiveReport, DnsReport, JoinedReport, LeftReport, MAX_MESSAGE_LEN, Request, Response,
StatusReport,
// The transport-agnostic surface, re-exported so this module is a complete
// view of the local control interface on its own.
pub use super::{
CONTROL_PROTOCOL, EXCHANGE_TIMEOUT, ReportSource, is_serving, join_network, leave_network,
request_status, set_active, set_dns, set_hostname,
};
/// Builds the report that answers a status request.
///
/// Supplied by the caller, because only the caller knows which plugins are
/// running and what they can report. That is what keeps this module free of
/// any knowledge of them.
pub trait ReportSource: Send + Sync + 'static {
/// Produces a fresh report.
fn report(&self) -> BoxFuture<'_, StatusReport>;
/// Changes the name the agent answers to, returning the accepted form.
///
/// Defaulted to a refusal so that a source which only reports — the
/// closure impl below, and every test that uses it — stays valid and
/// says plainly that it cannot do this, rather than appearing to.
fn set_hostname(
&self,
_hostname: String,
) -> BoxFuture<'_, std::result::Result<String, String>> {
Box::pin(async move { Err("this agent cannot change its hostname".to_string()) })
}
/// Leaves a network, publishing a release first.
///
/// Defaulted to a refusal for the same reason as the above: a source
/// that only reports says so plainly rather than appearing to do it.
fn leave(&self, _network_id: String) -> BoxFuture<'_, std::result::Result<LeftReport, String>> {
Box::pin(async move { Err("this agent cannot leave a network".to_string()) })
}
/// Joins a network, or starts one that is configured and not running.
///
/// Defaulted to a refusal, like the others: a source that only reports
/// says so rather than appearing to have done it.
fn join(
&self,
_name: String,
_secret: String,
) -> BoxFuture<'_, std::result::Result<JoinedReport, String>> {
Box::pin(async move { Err("this agent cannot join a network".to_string()) })
}
/// Stops serving a network, or starts serving it again.
///
/// Defaulted to a refusal, like the others.
fn set_active(
&self,
_network_id: String,
_active: bool,
) -> BoxFuture<'_, std::result::Result<ActiveReport, String>> {
Box::pin(async move { Err("this agent cannot stop or start a network".to_string()) })
}
/// Turns the local resolver on or off while the agent runs.
///
/// Defaulted to a refusal, like the others.
fn set_dns(
&self,
_enable: bool,
_port: Option<u16>,
) -> BoxFuture<'_, std::result::Result<Option<DnsReport>, String>> {
Box::pin(async move { Err("this agent cannot serve DNS".to_string()) })
}
}
impl<F> ReportSource for F
where
F: Fn() -> BoxFuture<'static, StatusReport> + Send + Sync + 'static,
{
fn report(&self) -> BoxFuture<'_, StatusReport> {
(self)()
}
}
/// Serves the local control interface on a Unix socket.
#[derive(Debug)]
pub struct ControlSocket {
@@ -115,19 +47,15 @@ impl ControlSocket {
}
if path.exists() {
match UnixStream::connect(&path).await {
Ok(_) => {
if is_serving(&path).await {
return Err(Error::StateLocked { path: path.clone() });
}
// Nothing is listening, so the file is a leftover.
Err(_) => {
std::fs::remove_file(&path).map_err(|source| Error::Io {
path: path.clone(),
source,
})?;
}
}
}
let listener = UnixListener::bind(&path).map_err(|source| Error::Io {
path: path.clone(),
@@ -166,7 +94,6 @@ impl Drop for ControlSocket {
}
}
#[cfg(unix)]
fn restrict(path: &Path) -> Result<()> {
use std::os::unix::fs::PermissionsExt;
std::fs::set_permissions(path, std::fs::Permissions::from_mode(0o600)).map_err(|source| {
@@ -184,248 +111,35 @@ async fn serve(listener: UnixListener, source: Arc<dyn ReportSource>) {
};
let source = Arc::clone(&source);
tokio::spawn(async move {
if let Err(err) = handle(stream, source).await {
if let Err(err) = super::serve_connection(stream, source).await {
tracing::debug!(%err, "local control request failed");
}
});
}
}
async fn handle(mut stream: UnixStream, source: Arc<dyn ReportSource>) -> Result<()> {
// Bounded, so a connection that sends nothing cannot hold a task open.
// Only the wait for the request: building the report afterwards takes as
// long as it takes, and cutting it off would answer a live client with a
// closed socket.
let request: Request =
match tokio::time::timeout(EXCHANGE_TIMEOUT, read_message(&mut stream)).await {
Ok(request) => request?,
Err(_) => {
return Err(Error::Timeout {
what: "a local control connection".to_string(),
});
}
};
let response = match request {
Request::Status => Response::Status(Box::new(source.report().await)),
Request::SetHostname(hostname) => match source.set_hostname(hostname).await {
Ok(accepted) => Response::Hostname(accepted),
Err(reason) => Response::Error(reason),
},
Request::Leave(network_id) => match source.leave(network_id).await {
Ok(report) => Response::Left(report),
Err(reason) => Response::Error(reason),
},
Request::Join { name, secret } => match source.join(name, secret).await {
Ok(report) => Response::Joined(report),
Err(reason) => Response::Error(reason),
},
Request::SetActive { network_id, active } => {
match source.set_active(network_id, active).await {
Ok(report) => Response::Active(report),
Err(reason) => Response::Error(reason),
}
}
Request::Dns { enable, port } => match source.set_dns(enable, port).await {
Ok(report) => Response::Dns(report),
Err(reason) => Response::Error(reason),
},
};
write_message(&mut stream, &response).await
}
/// How long either end waits for the other.
///
/// A local answer comes from memory, so anything this slow means the agent is
/// wedged rather than busy. Saying so beats waiting: unbounded, one wedged
/// runtime leaves `tsunagi status` hanging with nothing on screen and no way
/// out but Ctrl-C.
const EXCHANGE_TIMEOUT: Duration = Duration::from_secs(5);
/// Asks a running agent for its status.
pub async fn request_status(path: impl AsRef<Path>) -> Result<StatusReport> {
let path = path.as_ref();
match exchange(path, &Request::Status, EXCHANGE_TIMEOUT).await? {
Response::Status(report) => Ok(*report),
Response::Error(reason) => Err(Error::Storage(reason)),
other => Err(Error::Storage(format!("unexpected answer: {other:?}"))),
}
}
/// Asks a running agent to answer to a different name.
///
/// Returns the name it accepted, which is the canonical form of what was
/// asked for and may differ from it.
pub async fn set_hostname(path: impl AsRef<Path>, hostname: &str) -> Result<String> {
let path = path.as_ref();
let request = Request::SetHostname(hostname.to_string());
match exchange(path, &request, EXCHANGE_TIMEOUT).await? {
Response::Hostname(accepted) => Ok(accepted),
Response::Error(reason) => Err(Error::Storage(reason)),
other => Err(Error::Storage(format!("unexpected answer: {other:?}"))),
}
}
/// Connects, sends one request and reads the answer, all within `within`.
///
/// The bound covers the whole exchange rather than each read: an agent that
/// answers the header and then stops is as stuck as one that never answers.
async fn exchange(path: &Path, request: &Request, within: Duration) -> Result<Response> {
let attempt = async {
let mut stream = UnixStream::connect(path)
.await
.map_err(|source| Error::Io {
/// Connects a client to the socket at `path`.
pub(crate) async fn connect(path: &Path) -> Result<UnixStream> {
UnixStream::connect(path).await.map_err(|source| Error::Io {
path: path.to_path_buf(),
source,
})?;
write_message(&mut stream, request).await?;
read_message::<Response>(&mut stream).await
};
match tokio::time::timeout(within, attempt).await {
Ok(result) => result,
Err(_) => Err(Error::Timeout {
what: format!("the agent at {}", path.display()),
}),
}
})
}
/// Asks a running agent to leave a network.
///
/// The agent publishes the release and removes the network; this only
/// carries the request and the outcome.
pub async fn leave_network(path: impl AsRef<Path>, network_id: &str) -> Result<LeftReport> {
let path = path.as_ref();
let request = Request::Leave(network_id.to_string());
match exchange(path, &request, EXCHANGE_TIMEOUT).await? {
Response::Left(report) => Ok(report),
Response::Error(reason) => Err(Error::Storage(reason)),
other => Err(Error::Storage(format!("unexpected answer: {other:?}"))),
}
}
/// Asks a running agent to join a network.
///
/// The one way to add a network to an agent that is already up: the state
/// directory belongs to one live agent, so a second `up` cannot.
pub async fn join_network(
path: impl AsRef<Path>,
name: &str,
secret: &str,
) -> Result<JoinedReport> {
let path = path.as_ref();
let request = Request::Join {
name: name.to_string(),
secret: secret.to_string(),
};
match exchange(path, &request, EXCHANGE_TIMEOUT).await? {
Response::Joined(report) => Ok(report),
Response::Error(reason) => Err(Error::Storage(reason)),
other => Err(Error::Storage(format!("unexpected answer: {other:?}"))),
}
}
/// Asks a running agent to stop serving a network, or to serve it again.
pub async fn set_active(
path: impl AsRef<Path>,
network_id: &str,
active: bool,
) -> Result<ActiveReport> {
let path = path.as_ref();
let request = Request::SetActive {
network_id: network_id.to_string(),
active,
};
match exchange(path, &request, EXCHANGE_TIMEOUT).await? {
Response::Active(report) => Ok(report),
Response::Error(reason) => Err(Error::Storage(reason)),
other => Err(Error::Storage(format!("unexpected answer: {other:?}"))),
}
}
/// Turns the running agent's local resolver on or off.
pub async fn set_dns(
path: impl AsRef<Path>,
enable: bool,
port: Option<u16>,
) -> Result<Option<DnsReport>> {
let path = path.as_ref();
match exchange(path, &Request::Dns { enable, port }, EXCHANGE_TIMEOUT).await? {
Response::Dns(report) => Ok(report),
Response::Error(reason) => Err(Error::Storage(reason)),
other => Err(Error::Storage(format!("unexpected answer: {other:?}"))),
}
}
/// Marks the wire format of the local control socket.
///
/// `b"TSN"` followed by the version, so a mismatch is recognised as one
/// instead of being read as a length. The encoding is postcard, which is not
/// self-describing: adding a field to a report changes how the bytes parse,
/// and without this a client one build ahead of its agent reports something
/// like "Found an Option discriminant that wasn't 0 or 1" — which says
/// nothing about the actual problem, that the two are different builds.
///
/// Bump it whenever [`Request`], [`Response`] or anything they contain
/// changes shape.
pub const CONTROL_PROTOCOL: u32 = u32::from_be_bytes([b'T', b'S', b'N', 13]);
async fn write_message<T: serde::Serialize>(stream: &mut UnixStream, value: &T) -> Result<()> {
let encoded = postcard::to_stdvec(value)
.map_err(|err| Error::Storage(format!("cannot encode a control message: {err}")))?;
if encoded.len() > MAX_MESSAGE_LEN {
return Err(Error::Storage("control message is too large".into()));
}
let len = encoded.len() as u32;
stream
.write_all(&CONTROL_PROTOCOL.to_be_bytes())
.await
.map_err(io_error)?;
stream
.write_all(&len.to_be_bytes())
.await
.map_err(io_error)?;
stream.write_all(&encoded).await.map_err(io_error)?;
stream.flush().await.map_err(io_error)
}
async fn read_message<T: for<'de> serde::Deserialize<'de>>(stream: &mut UnixStream) -> Result<T> {
let mut header = [0u8; 4];
stream.read_exact(&mut header).await.map_err(io_error)?;
let version = u32::from_be_bytes(header);
if version != CONTROL_PROTOCOL {
return Err(Error::Storage(format!(
"the other end speaks control protocol {version:#010x} and this build speaks \
{CONTROL_PROTOCOL:#010x}; they are different builds of tsunagi, so restart the \
agent with the binary you are running now"
)));
}
stream.read_exact(&mut header).await.map_err(io_error)?;
let len = u32::from_be_bytes(header) as usize;
// Checked before allocating, exactly as on the network.
if len > MAX_MESSAGE_LEN {
return Err(Error::Storage(format!(
"control message of {len} bytes exceeds the {MAX_MESSAGE_LEN} byte limit"
)));
}
let mut payload = vec![0u8; len];
stream.read_exact(&mut payload).await.map_err(io_error)?;
postcard::from_bytes(&payload)
.map_err(|err| Error::Storage(format!("cannot decode a control message: {err}")))
}
fn io_error(source: std::io::Error) -> Error {
Error::Io {
path: PathBuf::from("<local control socket>"),
source,
}
/// Whether an agent is listening on the socket at `path`.
pub(crate) async fn probe(path: &Path) -> bool {
UnixStream::connect(path).await.is_ok()
}
#[cfg(test)]
mod tests {
#![allow(clippy::unwrap_used, clippy::expect_used, clippy::panic)]
use std::time::Duration;
use super::super::{Request, Response, StatusReport, exchange};
use super::*;
use crate::BoxFuture;
#[tokio::test]
async fn a_silent_agent_is_reported_rather_than_waited_out() {
crates/tsunagi/src/ipc/windows.rs
+284
View File
@@ -0,0 +1,284 @@
//! A named-pipe adapter for the local control interface.
//!
//! The Windows counterpart of [`super::unix`]. It provides only what is
//! particular to a named pipe — creating the server instance, opening a client
//! and turning the state directory path into a pipe name — and hands every
//! accepted connection to the shared [`serve_connection`](super::serve_connection).
//! The framing, the dispatch and the client wrappers are the same on every
//! platform and live in [`super`], re-exported here so `ipc::windows::request_status`
//! and its siblings resolve just as their Unix equivalents do.
//!
//! # From a path to a pipe
//!
//! The rest of the agent addresses the control interface by a filesystem path,
//! the same one a Unix socket would live at. A named pipe has no filesystem
//! path, so the path is hashed into a stable name under `\\.\pipe\`. The agent
//! and a client derive it the same way from the same path, so neither has to
//! be told where the other put it.
//!
//! # Who may connect
//!
//! The pipe rejects clients from other machines, and takes the process's
//! default security, under which the creating user has full access. Narrowing
//! that further with an explicit ACL needs a raw security-descriptor call this
//! crate forbids, so it is not attempted; on a single-user machine, and against
//! other unprivileged users, the default is the practical equivalent of the
//! owner-only Unix socket. There is no leftover to clean up: a pipe exists only
//! while its server does.
use std::path::{Path, PathBuf};
use std::sync::Arc;
use std::time::Duration;
use sha2::{Digest, Sha256};
use tokio::net::windows::named_pipe::{ClientOptions, NamedPipeClient, ServerOptions};
use tokio::task::JoinHandle;
use crate::error::{Error, Result};
pub use super::{
CONTROL_PROTOCOL, EXCHANGE_TIMEOUT, ReportSource, is_serving, join_network, leave_network,
request_status, set_active, set_dns, set_hostname,
};
/// `ERROR_ACCESS_DENIED`: what creating the first pipe instance returns when
/// one already exists, so another agent already owns the name.
const ERROR_ACCESS_DENIED: i32 = 5;
/// `ERROR_PIPE_BUSY`: every instance is serving a client right now. A server
/// is there; the client only has to wait for a free instance.
const ERROR_PIPE_BUSY: i32 = 231;
/// Serves the local control interface on a named pipe.
#[derive(Debug)]
pub struct ControlSocket {
path: PathBuf,
task: Option<JoinHandle<()>>,
}
impl ControlSocket {
/// Binds the pipe and starts serving.
///
/// Claiming the first instance of the name is what detects a second agent:
/// if the name already exists, the create is refused and that is reported
/// as the state being locked, so two live agents never share one pipe.
pub async fn bind(path: impl AsRef<Path>, source: Arc<dyn ReportSource>) -> Result<Self> {
let path = path.as_ref().to_path_buf();
let name = pipe_name(&path);
let server = match ServerOptions::new()
.first_pipe_instance(true)
.reject_remote_clients(true)
.create(&name)
{
Ok(server) => server,
Err(err) if err.raw_os_error() == Some(ERROR_ACCESS_DENIED) => {
return Err(Error::StateLocked { path });
}
Err(source) => return Err(Error::Io { path, source }),
};
let task = tokio::spawn(serve(name, server, source));
Ok(Self {
path,
task: Some(task),
})
}
/// The path the pipe name was derived from.
pub fn path(&self) -> &Path {
&self.path
}
/// Stops serving. The pipe goes with the server, so there is nothing to
/// remove.
pub async fn shutdown(mut self) {
if let Some(task) = self.task.take() {
task.abort();
let _ = task.await;
}
}
}
impl Drop for ControlSocket {
fn drop(&mut self) {
if let Some(task) = self.task.take() {
task.abort();
}
}
}
/// Accepts one client at a time, keeping a fresh instance ready for the next.
///
/// A named pipe server instance serves a single client, so a new instance is
/// created as soon as one is taken — otherwise a second `tsunagi status` while
/// the first is mid-flight would find nothing listening.
async fn serve(name: String, first: tokio::net::windows::named_pipe::NamedPipeServer, source: Arc<dyn ReportSource>) {
let mut server = first;
loop {
if server.connect().await.is_err() {
match next_instance(&name) {
Some(next) => {
server = next;
continue;
}
None => return,
}
}
let connected = server;
match next_instance(&name) {
Some(next) => server = next,
None => {
// Nothing left to accept the next client on, but the one in
// hand is still answered before the loop ends.
let source = Arc::clone(&source);
tokio::spawn(async move {
let _ = super::serve_connection(connected, source).await;
});
return;
}
}
let source = Arc::clone(&source);
tokio::spawn(async move {
if let Err(err) = super::serve_connection(connected, source).await {
tracing::debug!(%err, "local control request failed");
}
});
}
}
/// Creates the next pipe instance, or `None` if the name can no longer be
/// served.
fn next_instance(name: &str) -> Option<tokio::net::windows::named_pipe::NamedPipeServer> {
match ServerOptions::new().reject_remote_clients(true).create(name) {
Ok(server) => Some(server),
Err(err) => {
tracing::debug!(%err, "cannot create the next control pipe instance");
None
}
}
}
/// Connects a client to the pipe for `path`, waiting out a busy pipe.
///
/// The wait is bounded by the caller's exchange timeout, so a pipe that is
/// busy forever is given up on rather than spun on.
pub(crate) async fn connect(path: &Path) -> Result<NamedPipeClient> {
let name = pipe_name(path);
loop {
match ClientOptions::new().open(&name) {
Ok(client) => return Ok(client),
Err(err) if err.raw_os_error() == Some(ERROR_PIPE_BUSY) => {
tokio::time::sleep(Duration::from_millis(50)).await;
}
Err(source) => {
return Err(Error::Io {
path: path.to_path_buf(),
source,
});
}
}
}
}
/// Whether an agent is serving the pipe for `path`.
///
/// A busy pipe still means a server is there; only a name nothing has created
/// counts as not serving.
pub(crate) async fn probe(path: &Path) -> bool {
let name = pipe_name(path);
match ClientOptions::new().open(&name) {
Ok(_) => true,
Err(err) => err.raw_os_error() == Some(ERROR_PIPE_BUSY),
}
}
/// The pipe name for a control-socket path.
///
/// A hash rather than the path itself, because a pipe name may not contain the
/// separators and drive letters a path does, and because two agents with
/// different state directories must never collide.
fn pipe_name(path: &Path) -> String {
let digest = Sha256::digest(path.as_os_str().as_encoded_bytes());
format!(r"\\.\pipe\tsunagi-{}", hex::encode(&digest[..16]))
}
#[cfg(test)]
mod tests {
#![allow(clippy::unwrap_used, clippy::expect_used, clippy::panic)]
use std::time::Duration;
use super::super::{Request, Response, StatusReport, exchange};
use super::*;
use crate::BoxFuture;
#[test]
fn one_path_maps_to_one_name_and_two_paths_do_not_collide() {
let a = pipe_name(Path::new(r"C:\a\agent.sock"));
let b = pipe_name(Path::new(r"C:\b\agent.sock"));
assert!(a.starts_with(r"\\.\pipe\tsunagi-"), "{a}");
assert_eq!(a, pipe_name(Path::new(r"C:\a\agent.sock")));
assert_ne!(a, b);
}
#[tokio::test]
async fn a_request_makes_the_round_trip_over_a_real_pipe() {
let dir = tempfile::tempdir().unwrap();
let path = dir.path().join("agent.sock");
let source: Arc<dyn ReportSource> = Arc::new(|| -> BoxFuture<'static, StatusReport> {
Box::pin(async { StatusReport::default() })
});
assert!(!is_serving(&path).await, "nothing serves the pipe yet");
let control = ControlSocket::bind(&path, source).await.unwrap();
assert!(is_serving(&path).await, "the agent serves it now");
let answer = exchange(&path, &Request::Status, EXCHANGE_TIMEOUT)
.await
.unwrap();
assert!(matches!(answer, Response::Status(_)));
control.shutdown().await;
}
#[tokio::test]
async fn a_silent_agent_is_reported_rather_than_waited_out() {
let dir = tempfile::tempdir().unwrap();
let path = dir.path().join("agent.sock");
// A server instance that accepts and then never answers, like a
// wedged agent. Unbounded, the exchange below would never return.
let name = pipe_name(&path);
let server = ServerOptions::new()
.first_pipe_instance(true)
.create(&name)
.unwrap();
let _accept = tokio::spawn(async move {
let _ = server.connect().await;
// Hold the connection open, answering nothing.
tokio::time::sleep(Duration::from_secs(30)).await;
});
let error = exchange(&path, &Request::Status, Duration::from_millis(200))
.await
.expect_err("a silent agent cannot be reported as healthy");
assert!(matches!(error, Error::Timeout { .. }), "{error:?}");
}
#[tokio::test]
async fn a_second_agent_on_the_same_pipe_is_refused() {
let dir = tempfile::tempdir().unwrap();
let path = dir.path().join("agent.sock");
let source: Arc<dyn ReportSource> = Arc::new(|| -> BoxFuture<'static, StatusReport> {
Box::pin(async { StatusReport::default() })
});
let first = ControlSocket::bind(&path, Arc::clone(&source)).await.unwrap();
let second = ControlSocket::bind(&path, source).await;
assert!(
matches!(second, Err(Error::StateLocked { .. })),
"{second:?}"
);
first.shutdown().await;
}
}
crates/tsunagi/src/overlay/mod.rs
+3
View File
@@ -56,3 +56,6 @@ pub use tun::{MemoryTun, MemoryTunFactory, TunDevice, TunFactory, TunRequest, ad
#[cfg(all(feature = "tun-device", target_os = "linux"))]
pub use provision::NetlinkProvisioner;
#[cfg(all(feature = "tun-device", target_os = "windows"))]
pub use provision::WintunProvisioner;
crates/tsunagi/src/overlay/provision/mod.rs
+8 -1
View File
@@ -20,9 +20,11 @@
//! pure and tested on every platform, and only the execution is behind
//! [`InterfaceProvisioner`].
//!
//! Three implementations:
//! Four implementations:
//!
//! * `NetlinkProvisioner` on Linux, which needs `CAP_NET_ADMIN`.
//! * `WintunProvisioner` on Windows, a Wintun adapter configured with `netsh`,
//! which needs an elevated process.
//! * [`MockProvisioner`], an in-memory host used by the tests.
//! * [`UnsupportedProvisioner`] elsewhere, which fails with an explanation
//! and a pointer at the manual route rather than pretending to work.
@@ -51,6 +53,11 @@ mod linux;
#[cfg(all(feature = "tun-device", target_os = "linux"))]
pub use linux::NetlinkProvisioner;
#[cfg(all(feature = "tun-device", target_os = "windows"))]
mod windows;
#[cfg(all(feature = "tun-device", target_os = "windows"))]
pub use windows::WintunProvisioner;
mod privilege;
pub use privilege::{Privilege, probe_net_admin};
crates/tsunagi/src/overlay/provision/privilege.rs
+30 -2
View File
@@ -60,10 +60,19 @@ impl Privilege {
#[cfg(all(feature = "tun-device", target_os = "linux"))]
pub use linux_impl::{NetAdmin, probe_net_admin};
#[cfg(not(all(feature = "tun-device", target_os = "linux")))]
#[cfg(all(feature = "tun-device", target_os = "windows"))]
pub use windows_impl::probe_net_admin;
#[cfg(not(any(
all(feature = "tun-device", target_os = "linux"),
all(feature = "tun-device", target_os = "windows")
)))]
pub use other_impl::probe_net_admin;
#[cfg(not(all(feature = "tun-device", target_os = "linux")))]
#[cfg(not(any(
all(feature = "tun-device", target_os = "linux"),
all(feature = "tun-device", target_os = "windows")
)))]
mod other_impl {
use super::Privilege;
@@ -73,6 +82,25 @@ mod other_impl {
}
}
#[cfg(all(feature = "tun-device", target_os = "windows"))]
mod windows_impl {
use super::Privilege;
/// Whether this process can configure interfaces.
///
/// Windows has no capability to hold and lower the way Linux does:
/// creating an adapter simply needs the process to be elevated. Reading
/// whether it *is* elevated means inspecting the process token through a
/// raw call this crate forbids, so the probe is deliberately optimistic —
/// it reports that the platform can manage interfaces — and the real
/// check is left to Wintun's adapter creation, which fails with a precise
/// message when the process is not elevated. This matches how the Linux
/// path treats the open itself as the honest answer.
pub fn probe_net_admin() -> Privilege {
Privilege::Available
}
}
#[cfg(all(feature = "tun-device", target_os = "linux"))]
mod linux_impl {
use caps::{CapSet, Capability};
crates/tsunagi/src/overlay/provision/windows.rs
+502
View File
@@ -0,0 +1,502 @@
//! Managing the overlay interface on Windows, through Wintun and `netsh`.
//!
//! The shape is the same as the Linux provisioner: observe what is there,
//! [`plan_changes`](super::plan_changes) to decide what to do, apply the
//! difference. Only the two mechanisms differ.
//!
//! # Creating the interface
//!
//! The interface is a Wintun adapter, created through the `tun` dependency's
//! safe wrapper — [`open_tun`](super::super::tun) — because loading
//! `wintun.dll` is an `unsafe` call and this crate forbids `unsafe`. The
//! adapter is created, not made persistent: closing the last handle to it
//! removes it, so it goes away when the agent does, however the agent ends.
//! The reader and writer inside the device hold that handle, so the adapter
//! lives exactly as long as the device does.
//!
//! # Configuring it
//!
//! Addresses and MTU are applied with `netsh`. On Linux the same work is done
//! in process over a netlink socket; here there is no equivalent that this
//! crate may call, because the in-process route is the IP Helper API and that
//! is `unsafe`. `netsh` is the supported tool for the job, it is invoked by
//! absolute path from `%SystemRoot%` so nothing on `PATH` can stand in for it,
//! and every value handed to it is one this agent derived — an interface name
//! from the network id, an address it allocated — never anything a peer said.
//!
//! # Observing it
//!
//! The interface table is read through `netdev`, whose enumeration is a safe
//! wrapper over the same IP Helper API. An adapter is matched by the friendly
//! name it was created with. A match that carries a default gateway is treated
//! as foreign and left alone: a tsunagi overlay interface never has one, so a
//! gateway is the mark of a real device that happens to share the name.
//!
//! # What Windows cannot do that Linux can
//!
//! Wintun exposes no way to delete an adapter this process did not create, so
//! a leftover from a run that was killed is *reused* rather than replaced: its
//! addresses are flushed and the planned ones applied, which reaches the same
//! end state. A reused adapter is not removed on exit, only closed — that is a
//! Wintun limitation, and the common case of a clean start and a clean stop is
//! unaffected.
use std::net::{IpAddr, Ipv4Addr};
use std::sync::{Arc, Mutex};
use crate::BoxFuture;
use crate::overlay::OverlayError;
use super::super::config::Cidr;
use super::super::tun::{TunDevice, TunRequest, open_tun};
use super::privilege::{Privilege, probe_net_admin};
use super::{
InterfacePlan, InterfaceProvisioner, InterfaceState, LinkKind, Provisioned, plan_changes,
};
/// Manages the overlay interface with Wintun and `netsh`.
#[derive(Debug)]
pub struct WintunProvisioner {
/// Interfaces this process created, so they are adjusted rather than
/// replaced. See [`plan_changes`].
ours: Mutex<Vec<String>>,
/// Devices kept alive for as long as the interface should exist. Dropping
/// one closes the adapter, which removes it if this process created it.
held: Mutex<Vec<(String, Arc<dyn TunDevice>)>>,
}
impl WintunProvisioner {
/// Creates the provisioner, after checking the platform supports one.
///
/// Whether the process is actually elevated is not checked here — that
/// cannot be read without an `unsafe` call — so a missing privilege
/// surfaces at adapter creation with a precise message, the same way the
/// Linux path treats the open itself as the honest answer.
pub fn new() -> Result<Self, OverlayError> {
match probe_net_admin() {
Privilege::Available => {}
Privilege::Missing(reason) => return Err(OverlayError::Unavailable(reason)),
Privilege::Unsupported => {
return Err(OverlayError::Unavailable(
"interface management is not compiled in".to_string(),
));
}
}
Ok(Self {
ours: Mutex::new(Vec::new()),
held: Mutex::new(Vec::new()),
})
}
fn is_ours(&self, name: &str) -> bool {
lock(&self.ours)
.iter()
.any(|owned| owned.eq_ignore_ascii_case(name))
}
/// Opens the Wintun adapter, which is what creates it.
fn create_device(&self, plan: &InterfacePlan) -> Result<Arc<dyn TunDevice>, OverlayError> {
let request = TunRequest::bare(plan.name.clone(), plan.mtu);
open_tun(&request)
}
}
impl InterfaceProvisioner for WintunProvisioner {
fn name(&self) -> &str {
"wintun"
}
fn reconcile<'a>(
&'a self,
plan: &'a InterfacePlan,
) -> BoxFuture<'a, Result<Provisioned, OverlayError>> {
Box::pin(async move {
let current = observe(&plan.name).await;
let changes = plan_changes(&current, plan, self.is_ours(&plan.name))?;
// Wintun cannot delete an adapter this process did not create, so a
// "delete then create" from `plan_changes` becomes "flush then
// reuse": clear the stale addresses off the interface that is
// there, and let the create step below reopen the same adapter.
// The end state — an adapter carrying exactly the plan's addresses
// — is identical.
let flush: Vec<Cidr> = if changes.delete_link {
tracing::info!(
interface = %plan.name,
"reusing an abandoned interface left by an earlier run"
);
current.addresses.clone()
} else {
Vec::new()
};
for cidr in flush.iter().chain(changes.remove.iter()) {
// Best effort: an address that is already gone is the outcome
// wanted, and refusing to start over one is not worth it.
if let Err(err) = address_del(&plan.name, *cidr).await {
tracing::debug!(interface = %plan.name, %cidr, %err, "could not remove address");
}
}
let device = if changes.create_link {
let device = self.create_device(plan)?;
lock(&self.ours).push(plan.name.clone());
lock(&self.held).push((plan.name.clone(), Arc::clone(&device)));
Some(device)
} else {
None
};
// A failure past this point leaves an interface that exists but
// cannot carry traffic. Undo the bookkeeping for one we just
// created so it is not mistaken for a working interface, and drop
// the device so the adapter closes.
let configured = configure(plan, &changes).await;
if let Err(err) = configured {
if changes.create_link {
lock(&self.held).retain(|(held, _)| held != &plan.name);
lock(&self.ours).retain(|owned| owned != &plan.name);
}
return Err(err);
}
Ok(Provisioned { changes, device })
})
}
fn remove<'a>(&'a self, name: &'a str) -> BoxFuture<'a, Result<(), OverlayError>> {
Box::pin(async move {
// Dropping the device closes the adapter, which removes it if this
// process created it. A reused adapter is only closed, not removed;
// flushing its addresses first keeps no stale configuration behind.
let current = observe(name).await;
for cidr in &current.addresses {
if let Err(err) = address_del(name, *cidr).await {
tracing::debug!(interface = %name, %cidr, %err, "could not remove address");
}
}
lock(&self.held).retain(|(held, _)| !held.eq_ignore_ascii_case(name));
lock(&self.ours).retain(|owned| !owned.eq_ignore_ascii_case(name));
Ok(())
})
}
}
fn lock<T>(mutex: &Mutex<T>) -> std::sync::MutexGuard<'_, T> {
match mutex.lock() {
Ok(guard) => guard,
Err(poisoned) => poisoned.into_inner(),
}
}
/// `fe80::/10` and `169.254.0.0/16`, which Windows assigns on its own.
fn is_link_local(addr: IpAddr) -> bool {
match addr {
IpAddr::V4(addr) => addr.is_link_local(),
IpAddr::V6(addr) => (addr.segments()[0] & 0xffc0) == 0xfe80,
}
}
/// What the interface named `name` currently looks like.
///
/// Never fails: a name nothing is using reads as [`InterfaceState::absent`],
/// which is what the plan then acts on.
async fn observe(name: &str) -> InterfaceState {
let name = name.to_string();
let found = tokio::task::spawn_blocking(move || {
netdev::get_interfaces()
.into_iter()
.find(|iface| match &iface.friendly_name {
Some(friendly) => friendly.eq_ignore_ascii_case(&name),
None => false,
})
})
.await
.ok()
.flatten();
let Some(iface) = found else {
return InterfaceState::absent();
};
let mut addresses: Vec<Cidr> = Vec::new();
for net in &iface.ipv4 {
if let Ok(cidr) = Cidr::new(IpAddr::V4(net.addr()), net.prefix_len())
&& !is_link_local(cidr.addr)
{
addresses.push(cidr);
}
}
for net in &iface.ipv6 {
if let Ok(cidr) = Cidr::new(IpAddr::V6(net.addr()), net.prefix_len())
&& !is_link_local(cidr.addr)
{
addresses.push(cidr);
}
}
addresses.sort();
// A tsunagi overlay interface only ever carries the addresses it was given
// and no gateway. One that has a gateway is a real device sharing the name,
// so it is foreign and never touched.
let kind = if iface.gateway.is_some() {
LinkKind::Foreign("gatewayed".to_string())
} else {
LinkKind::Tun
};
InterfaceState {
kind,
// Wintun reports an adapter with a live session as up and an abandoned
// one as down, so "up" doubles as "some process is holding it".
attached: iface.is_up(),
up: iface.is_up(),
mtu: iface.mtu.unwrap_or(0),
addresses,
}
}
/// Applies MTU, link state and addresses.
async fn configure(plan: &InterfacePlan, changes: &super::Changes) -> Result<(), OverlayError> {
if let Some(mtu) = changes.set_mtu {
set_mtu(&plan.name, mtu).await?;
}
for cidr in &changes.add {
address_add(&plan.name, *cidr).await?;
}
if changes.bring_up {
// Best effort: a Wintun adapter with a session is up already, and a
// failure to nudge it is not a reason to fail the whole reconcile.
if let Err(err) = set_up(&plan.name).await {
tracing::debug!(interface = %plan.name, %err, "could not enable the interface");
}
}
Ok(())
}
/// The dotted netmask for an IPv4 prefix length.
fn ipv4_mask(prefix_len: u8) -> Ipv4Addr {
if prefix_len == 0 {
Ipv4Addr::UNSPECIFIED
} else {
Ipv4Addr::from(u32::MAX << (32 - u32::from(prefix_len)))
}
}
/// The `netsh` arguments that add an address to an interface.
fn address_add_args(name: &str, cidr: Cidr) -> Vec<String> {
match cidr.addr {
IpAddr::V4(addr) => vec![
"interface".into(),
"ipv4".into(),
"add".into(),
"address".into(),
format!("name={name}"),
format!("address={addr}"),
format!("mask={}", ipv4_mask(cidr.prefix_len)),
"store=active".into(),
],
IpAddr::V6(addr) => vec![
"interface".into(),
"ipv6".into(),
"add".into(),
"address".into(),
format!("interface={name}"),
format!("address={addr}/{}", cidr.prefix_len),
"store=active".into(),
],
}
}
/// The `netsh` arguments that remove an address from an interface.
fn address_del_args(name: &str, cidr: Cidr) -> Vec<String> {
match cidr.addr {
IpAddr::V4(addr) => vec![
"interface".into(),
"ipv4".into(),
"delete".into(),
"address".into(),
format!("name={name}"),
format!("address={addr}"),
"store=active".into(),
],
IpAddr::V6(addr) => vec![
"interface".into(),
"ipv6".into(),
"delete".into(),
"address".into(),
format!("interface={name}"),
format!("address={addr}"),
"store=active".into(),
],
}
}
/// The `netsh` arguments that set an interface's MTU, one call per family.
fn mtu_args(name: &str, family: &str, mtu: u32) -> Vec<String> {
vec![
"interface".into(),
family.into(),
"set".into(),
"subinterface".into(),
name.into(),
format!("mtu={mtu}"),
"store=active".into(),
]
}
async fn address_add(name: &str, cidr: Cidr) -> Result<(), OverlayError> {
netsh(address_add_args(name, cidr)).await
}
async fn address_del(name: &str, cidr: Cidr) -> Result<(), OverlayError> {
netsh(address_del_args(name, cidr)).await
}
/// Sets the MTU on both families.
///
/// A family that is turned off on the adapter cannot take an MTU, so this
/// fails only when *neither* would — one family carrying the plan's MTU is
/// enough, and refusing the whole interface because the other is disabled
/// would be wrong.
async fn set_mtu(name: &str, mtu: u32) -> Result<(), OverlayError> {
let v4 = netsh(mtu_args(name, "ipv4", mtu)).await;
let v6 = netsh(mtu_args(name, "ipv6", mtu)).await;
match (&v4, &v6) {
(Err(_), Err(_)) => v4,
_ => {
if let Err(err) = &v4 {
tracing::debug!(interface = %name, %err, "could not set the IPv4 MTU");
}
if let Err(err) = &v6 {
tracing::debug!(interface = %name, %err, "could not set the IPv6 MTU");
}
Ok(())
}
}
}
async fn set_up(name: &str) -> Result<(), OverlayError> {
netsh(vec![
"interface".into(),
"set".into(),
"interface".into(),
format!("name={name}"),
"admin=enabled".into(),
])
.await
}
/// Runs `netsh` from `%SystemRoot%\System32`, so nothing on `PATH` can stand
/// in for it, and turns a non-zero exit into an error carrying what it said.
async fn netsh(args: Vec<String>) -> Result<(), OverlayError> {
let program = system32("netsh.exe");
let display = format!("netsh {}", args.join(" "));
let output = tokio::task::spawn_blocking(move || {
std::process::Command::new(program).args(&args).output()
})
.await
.map_err(|err| OverlayError::Other(format!("could not run {display}: {err}")))?
.map_err(|err| OverlayError::Unavailable(format!("could not run {display}: {err}")))?;
if output.status.success() {
return Ok(());
}
let message = {
let stderr = String::from_utf8_lossy(&output.stderr);
let text = if stderr.trim().is_empty() {
String::from_utf8_lossy(&output.stdout).trim().to_string()
} else {
stderr.trim().to_string()
};
if text.is_empty() {
format!("exit code {}", output.status)
} else {
text
}
};
Err(OverlayError::Unavailable(format!("{display} failed: {message}")))
}
/// The absolute path to a program in `System32`.
fn system32(exe: &str) -> std::path::PathBuf {
let root = std::env::var_os("SystemRoot").unwrap_or_else(|| r"C:\Windows".into());
std::path::Path::new(&root).join("System32").join(exe)
}
#[cfg(test)]
mod tests {
#![allow(clippy::unwrap_used, clippy::expect_used, clippy::panic)]
use super::*;
use std::net::Ipv6Addr;
fn v4(last: u8, prefix: u8) -> Cidr {
Cidr::new(IpAddr::V4(Ipv4Addr::new(10, 13, 37, last)), prefix).unwrap()
}
fn v6(last: u16) -> Cidr {
Cidr::new(IpAddr::V6(Ipv6Addr::new(0xfd00, 0, 0, 0, 0, 0, 0, last)), 64).unwrap()
}
#[test]
fn a_prefix_length_becomes_the_right_dotted_mask() {
assert_eq!(ipv4_mask(24), Ipv4Addr::new(255, 255, 255, 0));
assert_eq!(ipv4_mask(16), Ipv4Addr::new(255, 255, 0, 0));
assert_eq!(ipv4_mask(32), Ipv4Addr::new(255, 255, 255, 255));
assert_eq!(ipv4_mask(0), Ipv4Addr::UNSPECIFIED);
}
#[test]
fn a_v4_address_is_added_by_name_with_a_dotted_mask() {
let args = address_add_args("tsun0", v4(69, 24));
assert!(args.contains(&"ipv4".to_string()));
assert!(args.contains(&"add".to_string()));
assert!(args.contains(&"name=tsun0".to_string()));
assert!(args.contains(&"address=10.13.37.69".to_string()));
assert!(args.contains(&"mask=255.255.255.0".to_string()));
}
#[test]
fn a_v6_address_is_added_by_interface_with_a_prefix() {
let args = address_add_args("tsun0", v6(1));
assert!(args.contains(&"ipv6".to_string()));
assert!(args.contains(&"interface=tsun0".to_string()));
assert!(args.contains(&"address=fd00::1/64".to_string()));
}
#[test]
fn deleting_an_address_names_no_mask() {
let args = address_del_args("tsun0", v4(69, 24));
assert!(args.contains(&"delete".to_string()));
assert!(args.contains(&"address=10.13.37.69".to_string()));
assert!(!args.iter().any(|arg| arg.starts_with("mask=")));
}
#[test]
fn the_mtu_is_set_per_family_on_the_subinterface() {
let args = mtu_args("tsun0", "ipv4", 1280);
assert!(args.contains(&"subinterface".to_string()));
assert!(args.contains(&"tsun0".to_string()));
assert!(args.contains(&"mtu=1280".to_string()));
}
#[test]
fn link_local_addresses_are_not_ours_to_manage() {
assert!(is_link_local(IpAddr::V6(Ipv6Addr::new(
0xfe80, 0, 0, 0, 0, 0, 0, 1
))));
assert!(is_link_local(IpAddr::V4(Ipv4Addr::new(169, 254, 1, 1))));
assert!(!is_link_local(IpAddr::V4(Ipv4Addr::new(10, 13, 37, 1))));
assert!(!is_link_local(IpAddr::V6(Ipv6Addr::new(
0xfd00, 0, 0, 0, 0, 0, 0, 1
))));
}
#[test]
fn system32_is_absolute_and_ends_with_the_program() {
let path = system32("netsh.exe");
assert!(path.is_absolute(), "{path:?}");
assert!(path.ends_with("netsh.exe"), "{path:?}");
}
}
crates/tsunagi/src/overlay/tun.rs
+38 -11
View File
@@ -312,13 +312,17 @@ mod system {
/// A real TUN interface.
///
/// Created by opening `/dev/net/tun`, which needs `CAP_NET_ADMIN` and is
/// why [`open_tun`] is only ever called from
/// [`provision`](super::super::provision), where that capability is
/// raised for the length of the call and no longer.
/// On Linux it is created by opening `/dev/net/tun`, which needs
/// `CAP_NET_ADMIN`; on Windows it is a Wintun adapter, which needs the
/// process to be elevated and `wintun.dll` to be reachable. Either way
/// [`open_tun`] is only ever called from
/// [`provision`](super::super::provision), which holds whatever privilege
/// the platform requires for the length of the call and no longer.
///
/// It is deliberately **not** made persistent, so the kernel removes the
/// interface when this value is dropped — however the process ends.
/// It is deliberately **not** made persistent, so the operating system
/// removes the interface when this value is dropped — however the process
/// ends. (A Wintun adapter created this way is likewise torn down when the
/// last handle to it closes, which the reader and writer below hold.)
pub struct SystemTun {
name: String,
mtu: u32,
@@ -383,6 +387,7 @@ mod system {
pub(crate) fn open_tun(request: &TunRequest) -> Result<Arc<dyn TunDevice>, OverlayError> {
let mut config = tun::Configuration::default();
config.tun_name(&request.name);
#[cfg(target_os = "linux")]
config.platform_config(|platform| {
// The crate's own root check is not the check we want: this holds
// CAP_NET_ADMIN without being root. Whether the open succeeds is
@@ -391,14 +396,16 @@ mod system {
});
// Packet information stays off, so reads and writes are raw IP
// packets. `ip tuntap add ... mode tun` also defaults to no packet
// information, so the flags match when attaching to one.
// information, so the flags match when attaching to one. The address
// and MTU are left off the configuration on purpose: the provisioner
// applies those to the interface separately, the same way on every
// platform, so the plan stays the single source of what it carries.
let device = tun::create_as_async(&config).map_err(|err| {
OverlayError::Unavailable(format!(
"cannot create the TUN interface `{}`: {err}. Creating one needs \
CAP_NET_ADMIN; grant it with `setcap cap_net_admin+p`, or run with \
`--no-tun` to keep the tunnels off the operating system.",
request.name
"cannot create the TUN interface `{}`: {err}. {}",
request.name,
open_hint()
))
})?;
@@ -410,4 +417,24 @@ mod system {
writer: Mutex::new(writer),
}) as Arc<dyn TunDevice>)
}
/// The platform-appropriate tail of a "cannot create the interface" error:
/// what privilege it needs and the fallback that always works.
fn open_hint() -> &'static str {
#[cfg(target_os = "linux")]
{
"Creating one needs CAP_NET_ADMIN; grant it with `setcap cap_net_admin+p`, \
or run with `--no-tun` to keep the tunnels off the operating system."
}
#[cfg(target_os = "windows")]
{
"Creating one needs an elevated process and `wintun.dll` on the search path; \
run as Administrator with the DLL beside the executable, or run with `--no-tun` \
to keep the tunnels off the operating system."
}
#[cfg(not(any(target_os = "linux", target_os = "windows")))]
{
"Run with `--no-tun` to keep the tunnels off the operating system."
}
}
}