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//! Support for identifying a particular transport.
//!
//! A "transport" is a mechanism to connect to a relay on the Tor network and
//! make a `Channel`. Currently, two types of transports exist: the "built-in"
//! transport, which uses TLS over TCP, and various anti-censorship "pluggable
//! transports", which use TLS over other protocols to avoid detection by
//! censors.
use std::fmt::{self, Debug, Display};
use std::net::SocketAddr;
use std::slice;
use std::str::FromStr;
use safelog::Redactable;
use serde::{Deserialize, Serialize};
use thiserror::Error;
use crate::HasAddrs;
/// Identify a type of Transport.
///
/// If this crate is compiled with the `pt-client` feature, this type can
/// support pluggable transports; otherwise, only the built-in transport type is
/// supported.
/// This can be displayed as, or parsed from, a string.
/// `"-"` is used to indicate the builtin transport,
/// and `""` and `"bridge"` and `"<none>"` are also recognised for that.
//
// We recognise "bridge" as pluggable; "BRIDGE" is rejected as invalid.
#[derive(Debug, Clone, Default, Eq, PartialEq, Hash)]
pub struct TransportId(Inner);
/// Helper type to implement [`TransportId`].
/// This is a separate type so that TransportId can be opaque.
#[derive(Debug, Default, Clone, Eq, PartialEq, Hash)]
enum Inner {
/// The built-in transport type.
#[default]
BuiltIn,
/// A pluggable transport type, specified by its name.
#[cfg(feature = "pt-client")]
Pluggable(PtTransportName),
}
/// The name of a Pluggable Transport protocol.
/// The name has been syntax-checked.
/// These names are used to identify the particular transport protocol, such as
/// "obfs4" or "snowflake". They match a name of a protocol that the transport
/// binary knows how to provide to the name of a protocol that a bridge is
/// configured to use.
#[derive(
Debug,
Clone,
Default,
Eq,
PartialEq,
Hash,
serde_with::DeserializeFromStr,
serde_with::SerializeDisplay,
)]
pub struct PtTransportName(String);
impl FromStr for PtTransportName {
type Err = TransportIdError;
fn from_str(s: &str) -> Result<Self, Self::Err> {
s.to_string().try_into()
impl TryFrom<String> for PtTransportName {
type Error = TransportIdError;
fn try_from(s: String) -> Result<PtTransportName, Self::Error> {
if is_well_formed_id(&s) {
Ok(PtTransportName(s))
} else {
Err(TransportIdError::BadId(s))
impl Display for PtTransportName {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
Display::fmt(&self.0, f)
impl AsRef<str> for PtTransportName {
fn as_ref(&self) -> &str {
&self.0
/// These identifiers are used to indicate the built-in transport.
/// When outputting string representations, the first (`"-"`) is used.
// Actual pluggable transport names are restricted to the syntax of C identifiers.
// These strings are deliberately not in that syntax so as to avoid clashes.
// `"bridge"` is likewise prohibited by the spec.
const BUILT_IN_IDS: &[&str] = &["-", "", "bridge", "<none>"];
impl FromStr for TransportId {
if BUILT_IN_IDS.contains(&s) {
return Ok(TransportId(Inner::BuiltIn));
};
{
let name: PtTransportName = s.parse()?;
Ok(TransportId(Inner::Pluggable(name)))
#[cfg(not(feature = "pt-client"))]
Err(TransportIdError::NoSupport)
impl Display for TransportId {
match &self.0 {
Inner::BuiltIn => write!(f, "{}", BUILT_IN_IDS[0]),
Inner::Pluggable(name) => write!(f, "{}", name),
impl From<PtTransportName> for TransportId {
fn from(name: PtTransportName) -> Self {
TransportId(Inner::Pluggable(name))
/// Return true if `s` is a well-formed transport ID.
/// According to the specification, a well-formed transport ID follows the same
/// rules as a C99 identifier: It must follow the regular expression
/// `[a-zA-Z_][a-zA-Z0-9_]*`.
fn is_well_formed_id(s: &str) -> bool {
// It's okay to use a bytes iterator, since non-ascii strings are not
// allowed.
let mut bytes = s.bytes();
if let Some(first) = bytes.next() {
(first.is_ascii_alphabetic() || first == b'_')
&& bytes.all(|b| b.is_ascii_alphanumeric() || b == b'_')
&& !s.eq_ignore_ascii_case("bridge")
false
/// An error related to parsing a TransportId.
#[derive(Clone, Debug, thiserror::Error)]
#[non_exhaustive]
pub enum TransportIdError {
/// Arti was compiled without client-side pluggable transport support, and
/// we tried to use a pluggable transport.
#[error("Not compiled with pluggable transport support")]
NoSupport,
/// Tried to parse a pluggable transport whose name was not well-formed.
#[error("{0:?} is not a valid pluggable transport ID")]
BadId(String),
impl TransportId {
/// Return a new `TransportId` referencing the builtin transport
/// This is equivalent to the `Default` impl.
pub fn new_builtin() -> Self {
TransportId(Inner::BuiltIn)
/// Return a new `TransportId` referencing a pluggable transport
/// This is equivalent to the `From<PtTransportName>` impl.
pub fn new_pluggable(pt: PtTransportName) -> Self {
pt.into()
/// Return true if this is the built-in transport.
pub fn is_builtin(&self) -> bool {
self.0 == Inner::BuiltIn
/// Returns the pluggable transport name
/// Or `None` if `self` doesn't specify a pluggable transport
/// (e.g. if it specifies the builtin transport).
pub fn as_pluggable(&self) -> Option<&PtTransportName> {
Inner::BuiltIn => None,
Inner::Pluggable(pt) => Some(pt),
/// Consumes this `TransportId` and returns the pluggable transport name
pub fn into_pluggable(self) -> Option<PtTransportName> {
match self.0 {
/// This identifier is used to indicate no transport address.
const NONE_ADDR: &str = "-";
/// An address that an be passed to a pluggable transport to tell it where to
/// connect (typically, to a bridge).
/// Not every transport accepts all kinds of addresses.
/// This is semantically very similar to `Option<BridgeAddr>`,
/// but it has some of its own conversion methods and bespoke `FromStr` and `Display`.
// Implementations for `PtTargetAddr` are in terms of those for `BridgeAddr`
// wheresoever possible, to ensure that they do not diverge in semantics.
Clone, Debug, PartialEq, Eq, Hash, serde_with::DeserializeFromStr, serde_with::SerializeDisplay,
pub enum PtTargetAddr {
/// An IP address and port for a Tor relay.
/// This is the only address type supported by the BuiltIn transport.
IpPort(SocketAddr),
/// A hostname-and-port target address. Some transports may support this.
HostPort(String, u16),
/// A completely absent target address. Some transports support this.
None,
/// An address of a bridge, for use in configuration.
/// Contains precisely, either:
/// * A hostname (as a string), plus a `u16` port; or
/// * An (IPv4 or IPv6) socket address including port - i.e., a `SocketAddr`,
/// or to put it another way, an IP address (v4 or v6) plus a `u16` port.
/// Hostnames which are not syntactically invalid Internet hostnames,
/// and a port value of zero,
/// *can* be represented within a `BridgeAddr`.
derive_more::Display,
pub struct BridgeAddr(BridgeAddrInner<SocketAddr, String>);
/// `BridgeAddr` contents; type parameters allow use with references to avoid some copying
/// `SA` is always `SocketAddr` or `&SocketAddr`.
/// `HN` is always `String` or `&str`.
#[derive(Clone, Debug, PartialEq, Eq, Hash)]
enum BridgeAddrInner<SA, HN> {
/// An IP address and port for a bridge
IpPort(SA),
/// A hostname-and-port target address
HostPort(HN, u16),
// These methods have long slightly awkward names because we think
// we may want to change their names and types later, and/or deprecate them.
// So let's not use up the nice names now.
// TODO: decide on, and implement, a nicer API, or functions with nicer names.
// TODO: add From/Into conversions for SocketAddr and maybe (String, u16).
// TODO: consider providing constructor/accessor/deconstructor to/from Either.
impl BridgeAddr {
/// Create a new `BridgeAddr` referring to a numeric address and port
pub fn new_addr_from_sockaddr(sa: SocketAddr) -> Self {
BridgeAddr(BridgeAddrInner::IpPort(sa))
/// If this is a numeric address, return it as a `SocketAddr`
pub fn as_socketaddr(&self) -> Option<&SocketAddr> {
BridgeAddrInner::IpPort(sa) => Some(sa),
BridgeAddrInner::HostPort(..) => None,
pub fn new_named_host_port(hostname: impl Into<String>, port: u16) -> Self {
BridgeAddr(BridgeAddrInner::HostPort(hostname.into(), port))
/// If this is a named host and port, return it as hostname string and port
pub fn as_host_port(&self) -> Option<(&str, u16)> {
BridgeAddrInner::IpPort(..) => None,
BridgeAddrInner::HostPort(hn, port) => Some((hn, *port)),
impl From<PtTargetAddr> for Option<BridgeAddr> {
fn from(pt: PtTargetAddr) -> Option<BridgeAddr> {
match pt {
PtTargetAddr::IpPort(sa) => Some(BridgeAddrInner::IpPort(sa)),
PtTargetAddr::HostPort(hn, p) => Some(BridgeAddrInner::HostPort(hn, p)),
PtTargetAddr::None => None,
.map(BridgeAddr)
impl From<Option<BridgeAddr>> for PtTargetAddr {
fn from(pt: Option<BridgeAddr>) -> PtTargetAddr {
match pt.map(|ba| ba.0) {
Some(BridgeAddrInner::IpPort(sa)) => PtTargetAddr::IpPort(sa),
Some(BridgeAddrInner::HostPort(hn, p)) => PtTargetAddr::HostPort(hn, p),
None => PtTargetAddr::None,
/// An error from parsing a [`BridgeAddr`] or [`PtTargetAddr`].
pub enum BridgeAddrError {
/// We were compiled without support for addresses of this type.
#[error("Not compiled with pluggable transport support.")]
/// We cannot parse this address.
#[error("Cannot parse {0:?} as an address.")]
BadAddress(String),
impl FromStr for BridgeAddr {
type Err = BridgeAddrError;
Ok(BridgeAddr(if let Ok(addr) = s.parse() {
BridgeAddrInner::IpPort(addr)
} else if let Some((name, port)) = s.rsplit_once(':') {
let port = port
.parse()
.map_err(|_| BridgeAddrError::BadAddress(s.to_string()))?;
BridgeAddrInner::HostPort(name.to_string(), port)
return Err(BridgeAddrError::BadAddress(s.to_string()));
}))
impl FromStr for PtTargetAddr {
Ok(if s == NONE_ADDR {
PtTargetAddr::None
Some(BridgeAddr::from_str(s)?).into()
})
impl PtTargetAddr {
/// Obtain an `Option<BridgeAddrInner>` containing references
/// This is a useful helper for display-like implementations,
/// which can then implement for `PtTargetAddr` in terms of the impls for `BridgeAddrInner`.
/// (See the code comment for `PtTargetAddr`.)
fn as_bridge_ref(&self) -> Option<BridgeAddrInner<&SocketAddr, &str>> {
match self {
PtTargetAddr::IpPort(addr) => Some(BridgeAddrInner::IpPort(addr)),
PtTargetAddr::HostPort(host, port) => Some(BridgeAddrInner::HostPort(host, *port)),
impl<SA: Display, HN: Display> Display for BridgeAddrInner<SA, HN> {
BridgeAddrInner::IpPort(addr) => write!(f, "{}", addr),
BridgeAddrInner::HostPort(host, port) => write!(f, "{}:{}", host, port),
// impl Display for BridgeAddr is done with derive_more, on the struct definition.
impl Display for PtTargetAddr {
match self.as_bridge_ref() {
Some(b) => write!(f, "{}", b),
None => write!(f, "{}", NONE_ADDR),
impl<SA: Debug + Redactable, HN: Debug + Display + AsRef<str>> Redactable
for BridgeAddrInner<SA, HN>
fn display_redacted(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
BridgeAddrInner::IpPort(a) => a.display_redacted(f),
BridgeAddrInner::HostPort(host, port) => write!(f, "{}…:{}", &host.as_ref()[..2], port),
impl Redactable for BridgeAddr {
self.0.display_redacted(f)
impl Redactable for PtTargetAddr {
Some(b) => b.display_redacted(f),
/// A set of options to be passed along to a pluggable transport along with a
/// single target bridge relay.
/// These options typically describe aspects of the targeted bridge relay that
/// are not included in its address and Tor keys, such as additional
/// transport-specific keys or parameters.
/// This type is _not_ for settings that apply to _all_ of the connections over
/// a transport.
#[derive(Clone, Debug, Default, Eq, PartialEq, Hash, Serialize, Deserialize)]
#[serde(into = "Vec<(String, String)>", try_from = "Vec<(String, String)>")]
pub struct PtTargetSettings {
/// A list of (key,value) pairs
settings: Vec<(String, String)>,
impl PtTargetSettings {
/// Return an error if `k,v` is not a valid setting.
fn check_setting(k: &str, v: &str) -> Result<(), PtTargetInvalidSetting> {
// Unfortunately the spec is not very clear about the valid syntax.
// https://gitlab.torproject.org/tpo/core/torspec/-/issues/173
// For now we reject things that cannot be represented in a bridge line
if k.find(|c: char| c == '=' || c.is_whitespace()).is_some() {
return Err(PtTargetInvalidSetting::Key(k.to_string()));
if v.find(|c: char| c.is_whitespace()).is_some() {
return Err(PtTargetInvalidSetting::Value(v.to_string()));
Ok(())
/// Add `k,v` to this list of settings, if it is valid.
fn push_setting(
&mut self,
k: impl Into<String>,
v: impl Into<String>,
) -> Result<(), PtTargetInvalidSetting> {
let k = k.into();
let v = v.into();
Self::check_setting(&k, &v)?;
self.settings.push((k, v));
/// Return the inner list of (key, value) pairs
pub fn into_inner(self) -> Vec<(String, String)> {
self.settings
impl TryFrom<Vec<(String, String)>> for PtTargetSettings {
type Error = PtTargetInvalidSetting;
fn try_from(settings: Vec<(String, String)>) -> Result<Self, Self::Error> {
for (k, v) in settings.iter() {
Self::check_setting(k, v)?;
Ok(Self { settings })
impl From<PtTargetSettings> for Vec<(String, String)> {
fn from(settings: PtTargetSettings) -> Self {
settings.settings
/// The set of information passed to the pluggable transport subsystem in order
/// to establish a connection to a bridge relay.
#[derive(Clone, Debug, Eq, PartialEq, Hash, Serialize, Deserialize)]
pub struct PtTarget {
/// The transport to be used.
transport: PtTransportName,
/// The address of the bridge relay, if any.
addr: PtTargetAddr,
/// Any additional settings used by the transport.
#[serde(default)]
settings: PtTargetSettings,
/// Invalid PT parameter setting
#[derive(Error, Clone, Debug, Eq, PartialEq)]
pub enum PtTargetInvalidSetting {
/// Currently: the key contains whitespace or `=`
/// Will probably be generated for a greater variety of values
/// when the spec is more nailed down.
#[error("key {0:?} has invalid or unsupported syntax")]
Key(String),
/// Currently: the value contains whitespace
#[error("value {0:?} has invalid or unsupported syntax")]
Value(String),
impl PtTarget {
/// Create a new `PtTarget` (with no settings)
pub fn new(transport: PtTransportName, addr: PtTargetAddr) -> Self {
PtTarget {
transport,
addr,
settings: Default::default(),
/// Add a setting (to be passed during the SOCKS handshake)
pub fn push_setting(
self.settings.push_setting(k, v)
/// Get the transport name
pub fn transport(&self) -> &PtTransportName {
&self.transport
/// Get the transport target address (or host and port)
pub fn addr(&self) -> &PtTargetAddr {
&self.addr
/// Iterate over the PT setting strings
pub fn settings(&self) -> impl Iterator<Item = (&str, &str)> {
self.settings.settings.iter().map(|(k, v)| (&**k, &**v))
/// Return all the advertized socket addresses to which this target may
/// connect.
/// Returns `Some(&[])` if there is no way to connect to this target, and
/// `None` if this target does not use `SocketAddr` to connect
/// NOTE that these are not necessarily an address to which you can open a
/// TCP connection! The address will be interpreted by the implementation of
/// this pluggable transport.
pub fn socket_addrs(&self) -> Option<&[std::net::SocketAddr]> {
addr: PtTargetAddr::IpPort(addr),
..
} => Some(std::slice::from_ref(addr)),
_ => None,
/// Consume the `PtTarget` and return the component parts
pub fn into_parts(self) -> (PtTransportName, PtTargetAddr, PtTargetSettings) {
(self.transport, self.addr, self.settings)
/// The way to approach a single relay in order to open a channel.
/// For direct connections, this is simply an address. For connections via a
/// pluggable transport, this includes information about the transport, and any
/// address and settings information that transport requires.
#[derive(Clone, Debug, Eq, PartialEq, Hash)]
pub enum ChannelMethod {
/// Connect to the relay directly at one of several addresses.
Direct(Vec<std::net::SocketAddr>),
/// Connect to a bridge relay via a pluggable transport.
Pluggable(PtTarget),
impl ChannelMethod {
/// Return all the advertized socket addresses to which this method may connect.
/// TCP connection! If this `ChannelMethod` is using a non-`Direct`
/// transport, then this address will be interpreted by that transport's
/// implementation.
ChannelMethod::Direct(addr) => Some(addr.as_ref()),
ChannelMethod::Pluggable(t) => t.socket_addrs(),
/// Return a BridgeAddr that this ChannelMethod uses.
// TODO this is kind of weird, what does Some(PtTargetAddr::None) mean?
pub fn target_addr(&self) -> Option<PtTargetAddr> {
ChannelMethod::Direct(addr) if !addr.is_empty() => Some(PtTargetAddr::IpPort(addr[0])),
ChannelMethod::Pluggable(PtTarget { addr, .. }) => Some(addr.clone()),
/// Return true if this is a method for a direct connection.
pub fn is_direct(&self) -> bool {
matches!(self, ChannelMethod::Direct(_))
/// Return an identifier for the Transport to be used by this `ChannelMethod`.
pub fn transport_id(&self) -> TransportId {
ChannelMethod::Direct(_) => TransportId::default(),
ChannelMethod::Pluggable(target) => target.transport().clone().into(),
/// Change this `ChannelMethod` by removing every socket address that
/// does not satisfy `pred`.
/// `Hostname` and `None` addresses are never removed.
/// Return an error if we have removed every address.
pub fn retain_addrs<P>(&mut self, pred: P) -> Result<(), RetainAddrsError>
where
P: Fn(&std::net::SocketAddr) -> bool,
use PtTargetAddr as Pt;
ChannelMethod::Direct(d) if d.is_empty() => {}
ChannelMethod::Direct(d) => {
d.retain(pred);
if d.is_empty() {
return Err(RetainAddrsError::NoAddrsLeft);
ChannelMethod::Pluggable(PtTarget { addr, .. }) => match addr {
Pt::IpPort(a) => {
if !pred(a) {
*addr = Pt::None;
Pt::HostPort(_, _) => {}
Pt::None => {}
},
/// Return true if every method to contact `self` is also a method to
/// contact `other`.
pub fn contained_by(&self, other: &ChannelMethod) -> bool {
use ChannelMethod as CM;
match (self, other) {
(CM::Direct(our_addrs), CM::Direct(their_addrs)) => {
our_addrs.iter().all(|a| their_addrs.contains(a))
(CM::Pluggable(our_target), CM::Pluggable(their_target)) => our_target == their_target,
(_, _) => false,
/// An error that occurred while filtering addresses from a ChanMethod.
pub enum RetainAddrsError {
/// We removed all of the addresses from this method.
#[error("All addresses were removed.")]
NoAddrsLeft,
impl HasAddrs for PtTargetAddr {
fn addrs(&self) -> &[SocketAddr] {
PtTargetAddr::IpPort(sockaddr) => slice::from_ref(sockaddr),
PtTargetAddr::HostPort(..) | PtTargetAddr::None => &[],
impl HasAddrs for ChannelMethod {
ChannelMethod::Direct(addrs) => addrs,
ChannelMethod::Pluggable(pt) => pt.addr.addrs(),
#[cfg(test)]
mod test {
// @@ begin test lint list maintained by maint/add_warning @@
#![allow(clippy::bool_assert_comparison)]
#![allow(clippy::clone_on_copy)]
#![allow(clippy::dbg_macro)]
#![allow(clippy::mixed_attributes_style)]
#![allow(clippy::print_stderr)]
#![allow(clippy::print_stdout)]
#![allow(clippy::single_char_pattern)]
#![allow(clippy::unwrap_used)]
#![allow(clippy::unchecked_duration_subtraction)]
#![allow(clippy::useless_vec)]
#![allow(clippy::needless_pass_by_value)]
//! <!-- @@ end test lint list maintained by maint/add_warning @@ -->
use super::*;
#[test]
fn builtin() {
assert!(TransportId::default().is_builtin());
assert_eq!(
TransportId::default(),
"<none>".parse().expect("Couldn't parse default ID")
);
fn nosupport() {
// We should get this error whenever we parse a non-default PT and we have no PT support.
assert!(matches!(
TransportId::from_str("obfs4"),
));
fn wellformed() {
for id in &["snowflake", "obfs4", "_ohai", "Z", "future_WORK2"] {
assert!(is_well_formed_id(id));
for id in &[" ", "Mölm", "12345", ""] {
assert!(!is_well_formed_id(id));
fn parsing() {
let obfs = TransportId::from_str("obfs4").unwrap();
let dflt = TransportId::default();
let dflt2 = TransportId::from_str("<none>").unwrap();
let dflt3 = TransportId::from_str("-").unwrap();
let dflt4 = TransportId::from_str("").unwrap();
let dflt5 = TransportId::from_str("bridge").unwrap();
let snow = TransportId::from_str("snowflake").unwrap();
let obfs_again = TransportId::from_str("obfs4").unwrap();
assert_eq!(obfs, obfs_again);
assert_eq!(dflt, dflt2);
assert_eq!(dflt, dflt3);
assert_eq!(dflt, dflt4);
assert_eq!(dflt, dflt5);
assert_ne!(snow, obfs);
assert_ne!(snow, dflt);
assert_eq!(dflt.to_string(), "-");
TransportId::from_str("12345"),
Err(TransportIdError::BadId(_))
TransportId::from_str("Bridge"),
fn addr() {
let chk_bridge_addr = |a: &PtTargetAddr, addr: &str| {
let ba: BridgeAddr = addr.parse().unwrap();
assert_eq!(&ba.to_string(), addr);
assert_eq!(&PtTargetAddr::from(Some(ba.clone())), a);
let reba: Option<BridgeAddr> = a.clone().into();
assert_eq!(reba.as_ref(), Some(&ba));
for addr in &["1.2.3.4:555", "[::1]:9999"] {
let a: PtTargetAddr = addr.parse().unwrap();
assert_eq!(&a.to_string(), addr);
let sa: SocketAddr = addr.parse().unwrap();
assert_eq!(a.addrs(), &[sa]);
chk_bridge_addr(&a, addr);
for addr in &["www.example.com:9100", "-"] {
assert_eq!(a.addrs(), &[]);
if a == PtTargetAddr::None {
let e = BridgeAddr::from_str(addr).unwrap_err();
assert!(matches!(e, BridgeAddrError::BadAddress(_)));
for addr in &["foobar", "<<<>>>"] {
let e = PtTargetAddr::from_str(addr).unwrap_err();
fn transport_id() {
let id1: TransportId = "<none>".parse().unwrap();
assert!(id1.is_builtin());
assert_eq!(id1.to_string(), "-".to_string());
let id2: TransportId = "obfs4".parse().unwrap();
assert_ne!(id2, id1);
assert!(!id2.is_builtin());
assert_eq!(id2.to_string(), "obfs4");
TransportId::from_str("==="),
fn settings() {
let s = PtTargetSettings::try_from(vec![]).unwrap();
assert_eq!(Vec::<_>::from(s), vec![]);
let v = vec![("abc".into(), "def".into()), ("ghi".into(), "jkl".into())];
let s = PtTargetSettings::try_from(v.clone()).unwrap();
assert_eq!(Vec::<_>::from(s), v);
let v = vec![("a=b".into(), "def".into())];
let s = PtTargetSettings::try_from(v);
assert!(matches!(s, Err(PtTargetInvalidSetting::Key(_))));
let v = vec![("abc".into(), "d ef".into())];
assert!(matches!(s, Err(PtTargetInvalidSetting::Value(_))));
fn chanmethod_direct() {
let a1 = "127.0.0.1:8080".parse().unwrap();
let a2 = "127.0.0.2:8181".parse().unwrap();
let a3 = "127.0.0.3:8282".parse().unwrap();
let m = ChannelMethod::Direct(vec![a1, a2]);
assert_eq!(m.socket_addrs(), Some(&[a1, a2][..]));
assert_eq!((m.target_addr()), Some(PtTargetAddr::IpPort(a1)));
assert!(m.is_direct());
assert_eq!(m.transport_id(), TransportId::default());
let m2 = ChannelMethod::Direct(vec![a1, a2, a3]);
assert!(m.contained_by(&m));
assert!(m.contained_by(&m2));
assert!(!m2.contained_by(&m));
let mut m3 = m2.clone();
m3.retain_addrs(|a| a.port() != 8282).unwrap();
assert_eq!(m3, m);
assert_ne!(m3, m2);
fn chanmethod_pt() {
use itertools::Itertools;
let transport = "giraffe".parse().unwrap();
let addr1 = PtTargetAddr::HostPort("pt.example.com".into(), 1234);
let target1 = PtTarget::new("giraffe".parse().unwrap(), addr1.clone());
let m1 = ChannelMethod::Pluggable(target1);
let addr2 = PtTargetAddr::IpPort("127.0.0.1:567".parse().unwrap());
let target2 = PtTarget::new("giraffe".parse().unwrap(), addr2.clone());
let m2 = ChannelMethod::Pluggable(target2);
let addr3 = PtTargetAddr::None;
let target3 = PtTarget::new("giraffe".parse().unwrap(), addr3.clone());
let m3 = ChannelMethod::Pluggable(target3);
assert_eq!(m1.socket_addrs(), None);
m2.socket_addrs(),
Some(&["127.0.0.1:567".parse().unwrap()][..])
assert_eq!(m3.socket_addrs(), None);
assert_eq!(m1.target_addr(), Some(addr1));
assert_eq!(m2.target_addr(), Some(addr2));
assert_eq!(m3.target_addr(), Some(addr3));
assert!(!m1.is_direct());
assert!(!m2.is_direct());
assert!(!m3.is_direct());
assert_eq!(m1.transport_id(), transport);
assert_eq!(m2.transport_id(), transport);
assert_eq!(m3.transport_id(), transport);
for v in [&m1, &m2, &m3].iter().combinations(2) {
let first = v[0];
let second = v[1];
assert_eq!(first.contained_by(second), first == second);
let mut m1new = m1.clone();
let mut m2new = m2.clone();
let mut m3new = m3.clone();
// this will retain the IpPort target, and ignore the other targets.
m1new.retain_addrs(|a| a.port() == 567).unwrap();
m2new.retain_addrs(|a| a.port() == 567).unwrap();
m3new.retain_addrs(|a| a.port() == 567).unwrap();
assert_eq!(m1new, m1);
assert_eq!(m2new, m2);
assert_eq!(m3new, m3);
// But if we try to remove the ipport target, we get an error.
m2new.retain_addrs(|a| a.port() == 999),
Err(RetainAddrsError::NoAddrsLeft)