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//! Exit policies: match patterns of addresses and/or ports.
//!
//! Every Tor relays has a set of address:port combinations that it
//! actually allows connections to. The set, abstractly, is the
//! relay's "exit policy".
//! Address policies can be transmitted in two forms. One is a "full
//! policy", that includes a list of rules that are applied in order
//! to represent addresses and ports. We represent this with the
//! AddrPolicy type.
//! In microdescriptors, and for IPv6 policies, policies are just
//! given a list of ports for which _most_ addresses are permitted.
//! We represent this kind of policy with the PortPolicy type.
//! TODO: This module probably belongs in a crate of its own, with
//! possibly only the parsing code in this crate.
mod addrpolicy;
mod portpolicy;
use std::fmt;
use std::str::FromStr;
use std::{collections::BTreeSet, fmt::Display};
use thiserror::Error;
use tor_basic_utils::iter_join;
pub use addrpolicy::{AddrPolicy, AddrPortPattern};
pub use portpolicy::PortPolicy;
use crate::NormalItemArgument;
use crate::parse2::{ArgumentError, ArgumentStream, ItemArgumentParseable};
/// Error from an unparsable or invalid policy.
#[derive(Debug, Error, Clone, PartialEq, Eq)]
#[non_exhaustive]
pub enum PolicyError {
/// A port was not a number in the range 1..65535
#[error("Invalid port")]
InvalidPort,
/// A port range had its starting-point higher than its ending point.
#[error("Invalid port range")]
InvalidRange,
/// An address could not be interpreted.
#[error("Invalid address")]
InvalidAddress,
/// Tried to use a bitmask or prefix len with the address "*".
// TODO maybe rename this, we never use masks, only prefix lengths
#[error("mask or prefix length with star")]
MaskWithStar,
/// A bit mask was out of range.
#[error("invalid prefix length or mask")]
InvalidMask,
/// A policy could not be parsed for some other reason.
#[error("Invalid policy")]
InvalidPolicy,
}
/// A PortRange is a set of consecutively numbered TCP or UDP ports.
///
/// # Example
/// ```
/// use tor_netdoc::types::policy::PortRange;
/// let r: PortRange = "22-8000".parse().unwrap();
/// assert!(r.contains(128));
/// assert!(r.contains(22));
/// assert!(r.contains(8000));
/// assert!(! r.contains(21));
/// assert!(! r.contains(8001));
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
#[allow(clippy::exhaustive_structs)]
pub struct PortRange {
/// The first port in this range.
lo: u16,
/// The last port in this range.
hi: u16,
impl PortRange {
/// Create a new port range spanning from lo to hi, asserting that
/// the correct invariants hold.
const fn new_unchecked(lo: u16, hi: u16) -> Self {
assert!(lo != 0);
assert!(lo <= hi);
PortRange { lo, hi }
/// Create a port range containing all ports.
pub const fn new_all() -> Self {
PortRange::new_unchecked(1, 65535)
/// Create a new PortRange.
/// The Portrange contains all ports between `lo` and `hi` inclusive.
/// Returns None if lo is greater than hi, or if either is zero.
pub fn new(lo: u16, hi: u16) -> Option<Self> {
if lo != 0 && lo <= hi {
Some(PortRange { lo, hi })
} else {
None
/// Return true if a port is in this range.
pub fn contains(&self, port: u16) -> bool {
self.lo <= port && port <= self.hi
/// Return true if this range contains all ports.
pub fn is_all(&self) -> bool {
self.lo == 1 && self.hi == 65535
/// Helper for binary search: compare this range to a port.
/// This range is "equal" to all ports that it contains. It is
/// "greater" than all ports that precede its starting point, and
/// "less" than all ports that follow its ending point.
fn compare_to_port(&self, port: u16) -> std::cmp::Ordering {
use std::cmp::Ordering::*;
if port < self.lo {
Greater
} else if port <= self.hi {
Equal
Less
/// A PortRange is displayed as a number if it contains a single port,
/// and as a start point and end point separated by a dash if it contains
/// more than one port.
impl Display for PortRange {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
if self.lo == self.hi {
write!(f, "{}", self.lo)
write!(f, "{}-{}", self.lo, self.hi)
impl FromStr for PortRange {
type Err = PolicyError;
fn from_str(s: &str) -> Result<Self, PolicyError> {
let (lo, hi) = match s.split_once('-') {
Some((lo, hi)) => (
lo.parse::<u16>().map_err(|_| PolicyError::InvalidPort)?,
hi.parse::<u16>().map_err(|_| PolicyError::InvalidPort)?,
),
None => {
// There was no hyphen, so try to parse this range as a singleton.
let v = s.parse::<u16>().map_err(|_| PolicyError::InvalidPort)?;
(v, v)
};
PortRange::new(lo, hi).ok_or(PolicyError::InvalidRange)
impl NormalItemArgument for PortRange {}
/// A collection of port ranges in a sorted order.
/// Please use this when storing multiple port ranges because it optimizies
/// them storage wise.
// TODO: We should rewrite most of this, the implementation has lots of
// potential for off-by-one errors and such.
#[derive(Debug, Clone, PartialEq, Eq, Hash, Default)]
// Invariant:
//
// The `PortRange`s are valid, nonoverlapping, non-abutting, and sorted.
struct PortRanges(Vec<PortRange>);
impl PortRanges {
/// Creates a new [`PortRanges`] collection with no elements in it.
fn new() -> Self {
Self(Vec::new())
/// Checks whether there are no ranges in this instance.
fn is_empty(&self) -> bool {
self.0.is_empty()
/// Adds a new range into this [`PortRanges`].
/// The ranges must be valid, nonoverlapping, and pushed in a monotonically increasing order,
/// meaning that inserting `400-500,450-600` or `400-500,500-600` are
/// invalid, whereas `400-500,501-600` and `400-500,501-600` are.
fn push_ordered(&mut self, item: PortRange) -> Result<(), PolicyError> {
if let Some(prev) = self.0.last() {
// TODO SPEC: We don't enforce this in Tor, but we probably
// should. See torspec#60.
if prev.hi >= item.lo {
return Err(PolicyError::InvalidPolicy);
} else if prev.hi == item.lo - 1 {
// We compress a-b,(b+1)-c into a-c.
let r = PortRange::new_unchecked(prev.lo, item.hi);
self.0.pop();
self.0.push(r);
return Ok(());
self.0.push(item);
Ok(())
/// Checks whether `port` is contained in a range.
/// Whether this means if `port` is allowed or rejected depends on the
/// surroundings (such as which field this `PortRage` is in,
/// or an associated [`RuleKind`]).
fn contains(&self, port: u16) -> bool {
debug_assert!(self.0.is_sorted_by(|a, b| a.lo < b.lo));
self.0
.binary_search_by(|range| range.compare_to_port(port))
.is_ok()
/// Returns an inverted [`PortRanges`].
/// For example, a [`PortRanges`] of `80-443` would become `1-79,444-65535`.
fn inverted(&self) -> PortRanges {
let mut prev_hi = 0;
let mut new_allowed = Vec::new();
for entry in &self.0 {
// ports prev_hi+1 through entry.lo-1 were rejected. We should
// make them allowed.
if entry.lo > prev_hi + 1 {
new_allowed.push(PortRange::new_unchecked(prev_hi + 1, entry.lo - 1));
prev_hi = entry.hi;
if prev_hi < 65535 {
new_allowed.push(PortRange::new_unchecked(prev_hi + 1, 65535));
PortRanges(new_allowed)
/// Inverts a [`PortRanges`] in place
fn invert(&mut self) {
*self = self.inverted();
/// Returns an iterator for [`PortRanges`].
fn iter(&self) -> impl Iterator<Item = &PortRange> + Clone {
self.0.iter()
/// If set of ranges is non-empty, returns a string representation
/// We don't provide a normal `Display` impl, because it would have to
/// emit the empty string for an empty range, which would be quite odd.
/// When displaying accept/reject ranges, the caller needs to
/// choose between prepending `accept` and prepending `reject`.
fn display(&self) -> Option<impl Display + '_> {
struct DisplayWrapper<'r>(&'r PortRanges);
impl Display for DisplayWrapper<'_> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{}", iter_join(",", self.0.iter()))
(!self.is_empty()).then_some(DisplayWrapper(self))
impl FromIterator<u16> for PortRanges {
fn from_iter<I: IntoIterator<Item = u16>>(iter: I) -> Self {
// Collect all ports into a BTreeSet to have them sorted and deduped.
let ports = iter.into_iter().collect::<BTreeSet<_>>();
let mut ports = ports.into_iter().peekable();
let mut out = Self::new();
let mut current_min = None;
while let Some(port) = ports.next() {
if current_min.is_none() {
current_min = Some(port);
if let Some(next_port) = ports.peek().copied() {
// We do not have to worry about port == 65535, because then
// ports.peek() will be None, as each item in the BTreeSet is
// ordered and unique, implying that there won't be a successor
// to a port == 65535.
if next_port != port + 1 {
let _ = out.push_ordered(PortRange::new_unchecked(
current_min.expect("Don't have min port number"),
port,
));
current_min = None;
out
impl FromStr for PortRanges {
fn from_str(s: &str) -> Result<Self, Self::Err> {
// Pitfall: Do not use a clever iterator here because we need the result
// of .push() in order to avoid things such as `30-19`.
let mut ranges = Self::new();
for range in s.split(',') {
ranges.push_ordered(range.parse()?)?;
Ok(ranges)
impl ItemArgumentParseable for PortRanges {
/// [`PortRanges`] argument parser which is odd because port ranges are
/// syntactically a single argument although semantically multiple ones.
fn from_args<'s>(args: &mut ArgumentStream<'s>) -> Result<Self, ArgumentError> {
args.next()
.map(Self::from_str)
.unwrap_or(Ok(Self::new()))
.map_err(|_| ArgumentError::Invalid)
/// A kind of policy rule: either accepts or rejects addresses
/// matching a pattern.
#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash, derive_more::Display, derive_more::FromStr)]
#[display(rename_all = "lowercase")]
#[from_str(rename_all = "lowercase")]
#[allow(clippy::exhaustive_enums)]
pub enum RuleKind {
/// A rule that accepts matching address:port combinations.
Accept,
/// A rule that rejects matching address:port combinations.
Reject,
impl NormalItemArgument for RuleKind {}
#[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_time_subtraction)]
#![allow(clippy::useless_vec)]
#![allow(clippy::needless_pass_by_value)]
#![allow(clippy::string_slice)] // See arti#2571
//! <!-- @@ end test lint list maintained by maint/add_warning @@ -->
use super::*;
use crate::Result;
use crate::parse2::{self, ParseInput};
#[test]
fn parse_portrange() -> Result<()> {
assert_eq!(
"1-100".parse::<PortRange>()?,
PortRange::new(1, 100).unwrap()
);
"01-100".parse::<PortRange>()?,
assert_eq!("1-65535".parse::<PortRange>()?, PortRange::new_all());
"10-30".parse::<PortRange>()?,
PortRange::new(10, 30).unwrap()
"9001".parse::<PortRange>()?,
PortRange::new(9001, 9001).unwrap()
"9001-9001".parse::<PortRange>()?,
assert!("hello".parse::<PortRange>().is_err());
assert!("0".parse::<PortRange>().is_err());
assert!("65536".parse::<PortRange>().is_err());
assert!("65537".parse::<PortRange>().is_err());
assert!("1-2-3".parse::<PortRange>().is_err());
assert!("10-5".parse::<PortRange>().is_err());
assert!("1-".parse::<PortRange>().is_err());
assert!("-2".parse::<PortRange>().is_err());
assert!("-".parse::<PortRange>().is_err());
assert!("*".parse::<PortRange>().is_err());
fn pr_manip() {
assert!(PortRange::new_all().is_all());
assert!(!PortRange::new(2, 65535).unwrap().is_all());
assert!(PortRange::new_all().contains(1));
assert!(PortRange::new_all().contains(65535));
assert!(PortRange::new_all().contains(7777));
assert!(PortRange::new(20, 30).unwrap().contains(20));
assert!(PortRange::new(20, 30).unwrap().contains(25));
assert!(PortRange::new(20, 30).unwrap().contains(30));
assert!(!PortRange::new(20, 30).unwrap().contains(19));
assert!(!PortRange::new(20, 30).unwrap().contains(31));
assert_eq!(PortRange::new(20, 30).unwrap().compare_to_port(7), Greater);
assert_eq!(PortRange::new(20, 30).unwrap().compare_to_port(20), Equal);
assert_eq!(PortRange::new(20, 30).unwrap().compare_to_port(25), Equal);
assert_eq!(PortRange::new(20, 30).unwrap().compare_to_port(30), Equal);
assert_eq!(PortRange::new(20, 30).unwrap().compare_to_port(100), Less);
fn pr_fmt() {
fn chk(a: u16, b: u16, s: &str) {
let pr = PortRange::new(a, b).unwrap();
assert_eq!(format!("{}", pr), s);
chk(1, 65535, "1-65535");
chk(10, 20, "10-20");
chk(20, 20, "20");
fn port_ranges() {
const INPUT: &str = "22,80,443,8000-9000,9002";
let ranges = PortRanges::from_str(INPUT).unwrap();
ranges.0,
[
PortRange::new(22, 22).unwrap(),
PortRange::new(80, 80).unwrap(),
PortRange::new(443, 443).unwrap(),
PortRange::new(8000, 9000).unwrap(),
PortRange::new(9002, 9002).unwrap(),
]
assert!(ranges.contains(22));
assert!(ranges.contains(80));
assert!(ranges.contains(443));
assert!(ranges.contains(8000));
assert!(ranges.contains(8500));
assert!(ranges.contains(9000));
assert!(!ranges.contains(9001));
assert!(ranges.contains(9002));
let mut ranges_inverse = ranges.clone();
ranges_inverse.invert();
ranges_inverse.0,
PortRange::new(1, 21).unwrap(),
PortRange::new(23, 79).unwrap(),
PortRange::new(81, 442).unwrap(),
PortRange::new(444, 7999).unwrap(),
PortRange::new(9001, 9001).unwrap(),
PortRange::new(9003, 65535).unwrap(),
#[derive(derive_deftly::Deftly)]
#[derive_deftly(NetdocParseable)]
struct Dummy {
#[deftly(netdoc(single_arg))]
dummy: PortRanges,
let ranges2 =
parse2::parse_netdoc::<Dummy>(&ParseInput::new(&format!("dummy {INPUT}\n"), ""))
.unwrap();
assert_eq!(ranges, ranges2.dummy);