feat(transport): Add GlobalOnly Transport implementation

core/CHANGELOG.md

@@ -16,9 +16,13 @@
 - Remove `SingletonMuxer`.
   See [PR 3883].
 
+- Add `global_only::Transport` that refuses to dial IP addresses from private ranges.
+  See [PR 3814].
+
 [spec]: https://github.com/libp2p/specs/blob/master/connections/README.md#multistream-select
 [PR 3746]: https://github.com/libp2p/rust-libp2p/pull/3746
 [PR 3883]: https://github.com/libp2p/rust-libp2p/pull/3883
+[PR 3814]: https://github.com/libp2p/rust-libp2p/pull/3814
 
 ## 0.39.2
 

core/src/transport.rs

@@ -37,6 +37,7 @@ use std::{
 pub mod and_then;
 pub mod choice;
 pub mod dummy;
+pub mod global_only;
 pub mod map;
 pub mod map_err;
 pub mod memory;

core/src/transport/global_only.rs

@@ -0,0 +1,346 @@
+// Copyright 2023 Protocol Labs
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the "Software"),
+// to deal in the Software without restriction, including without limitation
+// the rights to use, copy, modify, merge, publish, distribute, sublicense,
+// and/or sell copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+use crate::{
+    multiaddr::{Multiaddr, Protocol},
+    transport::{ListenerId, TransportError, TransportEvent},
+};
+use log::debug;
+use std::{
+    pin::Pin,
+    task::{Context, Poll},
+};
+
+/// Dropping all dial requests to non-global IP addresses.
+#[derive(Debug, Clone, Default)]
+pub struct Transport<T> {
+    inner: T,
+}
+
+/// This module contains an implementation of the `is_global` IPv4 address space.
+///
+/// Credit for this implementation goes to the Rust standard library team.
+///
+/// Unstable tracking issue: [#27709](https://github.com/rust-lang/rust/issues/27709)
+mod ipv4_global {
+    use std::net::Ipv4Addr;
+
+    /// Returns [`true`] if this address is reserved by IANA for future use. [IETF RFC 1112]
+    /// defines the block of reserved addresses as `240.0.0.0/4`. This range normally includes the
+    /// broadcast address `255.255.255.255`, but this implementation explicitly excludes it, since
+    /// it is obviously not reserved for future use.
+    ///
+    /// [IETF RFC 1112]: https://tools.ietf.org/html/rfc1112
+    ///
+    /// # Warning
+    ///
+    /// As IANA assigns new addresses, this method will be
+    /// updated. This may result in non-reserved addresses being
+    /// treated as reserved in code that relies on an outdated version
+    /// of this method.
+    #[must_use]
+    #[inline]
+    const fn is_reserved(a: Ipv4Addr) -> bool {
+        a.octets()[0] & 240 == 240 && !a.is_broadcast()
+    }
+
+    /// Returns [`true`] if this address part of the `198.18.0.0/15` range, which is reserved for
+    /// network devices benchmarking. This range is defined in [IETF RFC 2544] as `192.18.0.0`
+    /// through `198.19.255.255` but [errata 423] corrects it to `198.18.0.0/15`.
+    ///
+    /// [IETF RFC 2544]: https://tools.ietf.org/html/rfc2544
+    /// [errata 423]: https://www.rfc-editor.org/errata/eid423
+    #[must_use]
+    #[inline]
+    const fn is_benchmarking(a: Ipv4Addr) -> bool {
+        a.octets()[0] == 198 && (a.octets()[1] & 0xfe) == 18
+    }
+
+    /// Returns [`true`] if this address is part of the Shared Address Space defined in
+    /// [IETF RFC 6598] (`100.64.0.0/10`).
+    ///
+    /// [IETF RFC 6598]: https://tools.ietf.org/html/rfc6598
+    #[must_use]
+    #[inline]
+    const fn is_shared(a: Ipv4Addr) -> bool {
+        a.octets()[0] == 100 && (a.octets()[1] & 0b1100_0000 == 0b0100_0000)
+    }
+
+    /// Returns [`true`] if this is a private address.
+    ///
+    /// The private address ranges are defined in [IETF RFC 1918] and include:
+    ///
+    ///  - `10.0.0.0/8`
+    ///  - `172.16.0.0/12`
+    ///  - `192.168.0.0/16`
+    ///
+    /// [IETF RFC 1918]: https://tools.ietf.org/html/rfc1918
+    #[must_use]
+    #[inline]
+    const fn is_private(a: Ipv4Addr) -> bool {
+        match a.octets() {
+            [10, ..] => true,
+            [172, b, ..] if b >= 16 && b <= 31 => true,
+            [192, 168, ..] => true,
+            _ => false,
+        }
+    }
+
+    /// Returns [`true`] if the address appears to be globally reachable
+    /// as specified by the [IANA IPv4 Special-Purpose Address Registry].
+    /// Whether or not an address is practically reachable will depend on your network configuration.
+    ///
+    /// Most IPv4 addresses are globally reachable;
+    /// unless they are specifically defined as *not* globally reachable.
+    ///
+    /// Non-exhaustive list of notable addresses that are not globally reachable:
+    ///
+    /// - The [unspecified address] ([`is_unspecified`](Ipv4Addr::is_unspecified))
+    /// - Addresses reserved for private use ([`is_private`](Ipv4Addr::is_private))
+    /// - Addresses in the shared address space ([`is_shared`](Ipv4Addr::is_shared))
+    /// - Loopback addresses ([`is_loopback`](Ipv4Addr::is_loopback))
+    /// - Link-local addresses ([`is_link_local`](Ipv4Addr::is_link_local))
+    /// - Addresses reserved for documentation ([`is_documentation`](Ipv4Addr::is_documentation))
+    /// - Addresses reserved for benchmarking ([`is_benchmarking`](Ipv4Addr::is_benchmarking))
+    /// - Reserved addresses ([`is_reserved`](Ipv4Addr::is_reserved))
+    /// - The [broadcast address] ([`is_broadcast`](Ipv4Addr::is_broadcast))
+    ///
+    /// For the complete overview of which addresses are globally reachable, see the table at the [IANA IPv4 Special-Purpose Address Registry].
+    ///
+    /// [IANA IPv4 Special-Purpose Address Registry]: https://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml
+    /// [unspecified address]: Ipv4Addr::UNSPECIFIED
+    /// [broadcast address]: Ipv4Addr::BROADCAST
+    #[must_use]
+    #[inline]
+    pub(crate) const fn is_global(a: Ipv4Addr) -> bool {
+        !(a.octets()[0] == 0 // "This network"
+            || is_private(a)
+            || is_shared(a)
+            || a.is_loopback()
+            || a.is_link_local()
+            // addresses reserved for future protocols (`192.0.0.0/24`)
+            ||(a.octets()[0] == 192 && a.octets()[1] == 0 && a.octets()[2] == 0)
+            || a.is_documentation()
+            || is_benchmarking(a)
+            || is_reserved(a)
+            || a.is_broadcast())
+    }
+}
+
+/// This module contains an implementation of the `is_global` IPv6 address space.
+///
+/// Credit for this implementation goes to the Rust standard library team.
+///
+/// Unstable tracking issue: [#27709](https://github.com/rust-lang/rust/issues/27709)
+mod ipv6_global {
+    use std::net::Ipv6Addr;
+
+    /// Returns `true` if the address is a unicast address with link-local scope,
+    /// as defined in [RFC 4291].
+    ///
+    /// A unicast address has link-local scope if it has the prefix `fe80::/10`, as per [RFC 4291 section 2.4].
+    /// Note that this encompasses more addresses than those defined in [RFC 4291 section 2.5.6],
+    /// which describes "Link-Local IPv6 Unicast Addresses" as having the following stricter format:
+    ///
+    /// ```text
+    /// | 10 bits  |         54 bits         |          64 bits           |
+    /// +----------+-------------------------+----------------------------+
+    /// |1111111010|           0             |       interface ID         |
+    /// +----------+-------------------------+----------------------------+
+    /// ```
+    /// So while currently the only addresses with link-local scope an application will encounter are all in `fe80::/64`,
+    /// this might change in the future with the publication of new standards. More addresses in `fe80::/10` could be allocated,
+    /// and those addresses will have link-local scope.
+    ///
+    /// Also note that while [RFC 4291 section 2.5.3] mentions about the [loopback address] (`::1`) that "it is treated as having Link-Local scope",
+    /// this does not mean that the loopback address actually has link-local scope and this method will return `false` on it.
+    ///
+    /// [RFC 4291]: https://tools.ietf.org/html/rfc4291
+    /// [RFC 4291 section 2.4]: https://tools.ietf.org/html/rfc4291#section-2.4
+    /// [RFC 4291 section 2.5.3]: https://tools.ietf.org/html/rfc4291#section-2.5.3
+    /// [RFC 4291 section 2.5.6]: https://tools.ietf.org/html/rfc4291#section-2.5.6
+    /// [loopback address]: Ipv6Addr::LOCALHOST
+    #[must_use]
+    #[inline]
+    const fn is_unicast_link_local(a: Ipv6Addr) -> bool {
+        (a.segments()[0] & 0xffc0) == 0xfe80
+    }
+
+    /// Returns [`true`] if this is a unique local address (`fc00::/7`).
+    ///
+    /// This property is defined in [IETF RFC 4193].
+    ///
+    /// [IETF RFC 4193]: https://tools.ietf.org/html/rfc4193
+    #[must_use]
+    #[inline]
+    const fn is_unique_local(a: Ipv6Addr) -> bool {
+        (a.segments()[0] & 0xfe00) == 0xfc00
+    }
+
+    /// Returns [`true`] if this is an address reserved for documentation
+    /// (`2001:db8::/32`).
+    ///
+    /// This property is defined in [IETF RFC 3849].
+    ///
+    /// [IETF RFC 3849]: https://tools.ietf.org/html/rfc3849
+    #[must_use]
+    #[inline]
+    const fn is_documentation(a: Ipv6Addr) -> bool {
+        (a.segments()[0] == 0x2001) && (a.segments()[1] == 0xdb8)
+    }
+
+    /// Returns [`true`] if the address appears to be globally reachable
+    /// as specified by the [IANA IPv6 Special-Purpose Address Registry].
+    /// Whether or not an address is practically reachable will depend on your network configuration.
+    ///
+    /// Most IPv6 addresses are globally reachable;
+    /// unless they are specifically defined as *not* globally reachable.
+    ///
+    /// Non-exhaustive list of notable addresses that are not globally reachable:
+    /// - The [unspecified address] ([`is_unspecified`](Ipv6Addr::is_unspecified))
+    /// - The [loopback address] ([`is_loopback`](Ipv6Addr::is_loopback))
+    /// - IPv4-mapped addresses
+    /// - Addresses reserved for benchmarking
+    /// - Addresses reserved for documentation ([`is_documentation`](Ipv6Addr::is_documentation))
+    /// - Unique local addresses ([`is_unique_local`](Ipv6Addr::is_unique_local))
+    /// - Unicast addresses with link-local scope ([`is_unicast_link_local`](Ipv6Addr::is_unicast_link_local))
+    ///
+    /// For the complete overview of which addresses are globally reachable, see the table at the [IANA IPv6 Special-Purpose Address Registry].
+    ///
+    /// Note that an address having global scope is not the same as being globally reachable,
+    /// and there is no direct relation between the two concepts: There exist addresses with global scope
+    /// that are not globally reachable (for example unique local addresses),
+    /// and addresses that are globally reachable without having global scope
+    /// (multicast addresses with non-global scope).
+    ///
+    /// [IANA IPv6 Special-Purpose Address Registry]: https://www.iana.org/assignments/iana-ipv6-special-registry/iana-ipv6-special-registry.xhtml
+    /// [unspecified address]: Ipv6Addr::UNSPECIFIED
+    /// [loopback address]: Ipv6Addr::LOCALHOST
+    #[must_use]
+    #[inline]
+    pub(crate) const fn is_global(a: Ipv6Addr) -> bool {
+        !(a.is_unspecified()
+            || a.is_loopback()
+            // IPv4-mapped Address (`::ffff:0:0/96`)
+            || matches!(a.segments(), [0, 0, 0, 0, 0, 0xffff, _, _])
+            // IPv4-IPv6 Translat. (`64:ff9b:1::/48`)
+            || matches!(a.segments(), [0x64, 0xff9b, 1, _, _, _, _, _])
+            // Discard-Only Address Block (`100::/64`)
+            || matches!(a.segments(), [0x100, 0, 0, 0, _, _, _, _])
+            // IETF Protocol Assignments (`2001::/23`)
+            || (matches!(a.segments(), [0x2001, b, _, _, _, _, _, _] if b < 0x200)
+                && !(
+                    // Port Control Protocol Anycast (`2001:1::1`)
+                    u128::from_be_bytes(a.octets()) == 0x2001_0001_0000_0000_0000_0000_0000_0001
+                    // Traversal Using Relays around NAT Anycast (`2001:1::2`)
+                    || u128::from_be_bytes(a.octets()) == 0x2001_0001_0000_0000_0000_0000_0000_0002
+                    // AMT (`2001:3::/32`)
+                    || matches!(a.segments(), [0x2001, 3, _, _, _, _, _, _])
+                    // AS112-v6 (`2001:4:112::/48`)
+                    || matches!(a.segments(), [0x2001, 4, 0x112, _, _, _, _, _])
+                    // ORCHIDv2 (`2001:20::/28`)
+                    || matches!(a.segments(), [0x2001, b, _, _, _, _, _, _] if b >= 0x20 && b <= 0x2F)
+                ))
+            || is_documentation(a)
+            || is_unique_local(a)
+            || is_unicast_link_local(a))
+    }
+}
+
+impl<T> Transport<T> {
+    pub fn new(transport: T) -> Self {
+        Transport { inner: transport }
+    }
+}
+
+impl<T: crate::Transport + Unpin> crate::Transport for Transport<T> {
+    type Output = <T as crate::Transport>::Output;
+    type Error = <T as crate::Transport>::Error;
+    type ListenerUpgrade = <T as crate::Transport>::ListenerUpgrade;
+    type Dial = <T as crate::Transport>::Dial;
+
+    fn listen_on(&mut self, addr: Multiaddr) -> Result<ListenerId, TransportError<Self::Error>> {
+        self.inner.listen_on(addr)
+    }
+
+    fn remove_listener(&mut self, id: ListenerId) -> bool {
+        self.inner.remove_listener(id)
+    }
+
+    fn dial(&mut self, addr: Multiaddr) -> Result<Self::Dial, TransportError<Self::Error>> {
+        match addr.iter().next() {
+            Some(Protocol::Ip4(a)) => {
+                if !ipv4_global::is_global(a) {
+                    debug!("Not dialing non global IP address {:?}.", a);
+                    return Err(TransportError::MultiaddrNotSupported(addr));
+                }
+                self.inner.dial(addr)
+            }
+            Some(Protocol::Ip6(a)) => {
+                if !ipv6_global::is_global(a) {
+                    debug!("Not dialing non global IP address {:?}.", a);
+                    return Err(TransportError::MultiaddrNotSupported(addr));
+                }
+                self.inner.dial(addr)
+            }
+            _ => {
+                debug!("Not dialing unsupported Multiaddress {:?}.", addr);
+                Err(TransportError::MultiaddrNotSupported(addr))
+            }
+        }
+    }
+
+    fn dial_as_listener(
+        &mut self,
+        addr: Multiaddr,
+    ) -> Result<Self::Dial, TransportError<Self::Error>> {
+        match addr.iter().next() {
+            Some(Protocol::Ip4(a)) => {
+                if !ipv4_global::is_global(a) {
+                    debug!("Not dialing non global IP address {:?}.", a);
+                    return Err(TransportError::MultiaddrNotSupported(addr));
+                }
+                self.inner.dial_as_listener(addr)
+            }
+            Some(Protocol::Ip6(a)) => {
+                if !ipv6_global::is_global(a) {
+                    debug!("Not dialing non global IP address {:?}.", a);
+                    return Err(TransportError::MultiaddrNotSupported(addr));
+                }
+                self.inner.dial_as_listener(addr)
+            }
+            _ => {
+                debug!("Not dialing unsupported Multiaddress {:?}.", addr);
+                Err(TransportError::MultiaddrNotSupported(addr))
+            }
+        }
+    }
+
+    fn address_translation(&self, listen: &Multiaddr, observed: &Multiaddr) -> Option<Multiaddr> {
+        self.inner.address_translation(listen, observed)
+    }
+
+    fn poll(
+        mut self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+    ) -> Poll<TransportEvent<Self::ListenerUpgrade, Self::Error>> {
+        Pin::new(&mut self.inner).poll(cx)
+    }
+}