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Merged
moubctez merged 2 commits into from
Sep 2, 2026
Merged

Normalized IpAddrMask #141

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eb33a8b
Normalized IpAddrMask
moubctez Sep 1, 2026
3c7156c
Fix logging message
moubctez Sep 1, 2026
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6 changes: 3 additions & 3 deletions Cargo.lock
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106 changes: 79 additions & 27 deletions src/net.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,9 @@ use serde::{Deserialize, Serialize};

use crate::IpVersion;

const IPV4_BITS: u8 = 32;
const IPV6_BITS: u8 = 128;

/// IP address with CIDR.
#[derive(Clone, Debug, Eq, Hash, PartialEq)]
#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
Expand All @@ -34,8 +37,8 @@ impl IpAddrMask {
#[must_use]
pub fn host(address: IpAddr) -> Self {
let cidr = match address {
IpAddr::V4(_) => 32,
IpAddr::V6(_) => 128,
IpAddr::V4(_) => IPV4_BITS,
IpAddr::V6(_) => IPV6_BITS,
};
Self { address, cidr }
}
Expand All @@ -47,20 +50,12 @@ impl IpAddrMask {
match self.address {
IpAddr::V4(ip) => {
let addr = u32::from(ip);
let bits = if self.cidr >= 32 {
0
} else {
u32::MAX >> self.cidr
};
let bits = u32::MAX.unbounded_shr(u32::from(self.cidr));
IpAddr::V4(Ipv4Addr::from(addr | bits))
}
IpAddr::V6(ip) => {
let addr = u128::from(ip);
let bits = if self.cidr >= 128 {
0
} else {
u128::MAX >> self.cidr
};
let bits = u128::MAX.unbounded_shr(u32::from(self.cidr));
IpAddr::V6(Ipv6Addr::from(addr | bits))
}
}
Expand All @@ -71,19 +66,13 @@ impl IpAddrMask {
pub fn mask(&self) -> IpAddr {
match self.address {
IpAddr::V4(_) => {
let mask = if self.cidr == 0 {
0
} else {
u32::MAX << (32 - self.cidr)
};
let shift = Ipv4Addr::BITS - u32::from(self.cidr);
let mask = u32::MAX.unbounded_shl(shift);
IpAddr::V4(Ipv4Addr::from(mask))
}
IpAddr::V6(_) => {
let mask = if self.cidr == 0 {
0
} else {
u128::MAX << (128 - self.cidr)
};
let shift = Ipv6Addr::BITS - u32::from(self.cidr);
let mask = u128::MAX.unbounded_shl(shift);
IpAddr::V6(Ipv6Addr::from(mask))
}
}
Expand All @@ -93,9 +82,9 @@ impl IpAddrMask {
#[must_use]
pub fn is_host(&self) -> bool {
if self.address.is_ipv4() {
self.cidr == 32
self.cidr == IPV4_BITS
} else {
self.cidr == 128
self.cidr == IPV6_BITS
}
}

Expand All @@ -109,6 +98,27 @@ impl IpAddrMask {
}
}

/// Zeroes host bits, turning the address into a network address.
#[must_use]
pub fn normalized(&self) -> Self {
let address = match self.address {
IpAddr::V4(ip) => {
let shift = Ipv4Addr::BITS - u32::from(self.cidr);
let mask = u32::MAX.unbounded_shl(shift);
IpAddr::V4(Ipv4Addr::from(ip.to_bits() & mask))
}
IpAddr::V6(ip) => {
let shift = Ipv6Addr::BITS - u32::from(self.cidr);
let mask = u128::MAX.unbounded_shl(shift);
IpAddr::V6(Ipv6Addr::from(ip.to_bits() & mask))
}
};
Self {
address,
cidr: self.cidr,
}
}

#[cfg(target_os = "linux")]
#[must_use]
pub fn to_nlas_allowed_ip(&self) -> WireguardAllowedIp {
Expand Down Expand Up @@ -149,8 +159,8 @@ impl FromStr for IpAddrMask {
let ip = left.parse().map_err(|_| IpAddrParseError)?;
let cidr = right.parse().map_err(|_| IpAddrParseError)?;
let max_cidr = match ip {
IpAddr::V4(_) => 32,
IpAddr::V6(_) => 128,
IpAddr::V4(_) => IPV4_BITS,
IpAddr::V6(_) => IPV6_BITS,
};
if cidr > max_cidr {
return Err(IpAddrParseError);
Expand All @@ -160,7 +170,7 @@ impl FromStr for IpAddrMask {
let ip = ip_str.parse().map_err(|_| IpAddrParseError)?;
Ok(IpAddrMask {
address: ip,
cidr: if ip.is_ipv4() { 32 } else { 128 },
cidr: if ip.is_ipv4() { IPV4_BITS } else { IPV6_BITS },
})
}
}
Expand Down Expand Up @@ -266,4 +276,46 @@ mod tests {
))
);
}

#[test]
fn normalize() {
let ip = IpAddrMask::new(IpAddr::V4(Ipv4Addr::new(192, 168, 0, 1)), 24);
let norm = ip.normalized();
assert_eq!(norm.address, IpAddr::V4(Ipv4Addr::new(192, 168, 0, 0)));
assert_eq!(norm.cidr, 24);

let ip = IpAddrMask::new(IpAddr::V4(Ipv4Addr::new(169, 254, 219, 59)), 16);
let norm = ip.normalized();
assert_eq!(norm.address, IpAddr::V4(Ipv4Addr::new(169, 254, 0, 0)));

let ip = IpAddrMask::new(IpAddr::V4(Ipv4Addr::new(12, 34, 56, 78)), 32);
let norm = ip.normalized();
assert_eq!(norm.address, IpAddr::V4(Ipv4Addr::new(12, 34, 56, 78)));

let ip = IpAddrMask::new(IpAddr::V4(Ipv4Addr::new(12, 34, 56, 78)), 0);
let norm = ip.normalized();
assert_eq!(norm.address, IpAddr::V4(Ipv4Addr::UNSPECIFIED));
}

#[test]
fn normalize_v6() {
let ip = IpAddrMask::new(
IpAddr::V6(Ipv6Addr::new(0x2001, 0x0db8, 0, 0, 0, 0, 0x1428, 0x57ab)),
96,
);
let norm = ip.normalized();
assert_eq!(
norm.address,
IpAddr::V6(Ipv6Addr::new(0x2001, 0x0db8, 0, 0, 0, 0, 0, 0))
);
assert_eq!(norm.cidr, 96);

let ip = IpAddrMask::new(IpAddr::V6(Ipv6Addr::LOCALHOST), 128);
let norm = ip.normalized();
assert_eq!(norm.address, IpAddr::V6(Ipv6Addr::LOCALHOST));

let ip = IpAddrMask::new(IpAddr::V6(Ipv6Addr::LOCALHOST), 0);
let norm = ip.normalized();
assert_eq!(norm.address, IpAddr::V6(Ipv6Addr::UNSPECIFIED));
}
}
2 changes: 1 addition & 1 deletion src/utils.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -173,7 +173,7 @@ pub(crate) fn add_peer_routing(
}
let gateway_v6 = get_gateway(IpVersion::IPv6);
if let Ok(Some(gateway)) = gateway_v6 {
debug!("Default gateway for IPv4: {gateway}");
debug!("Default gateway for IPv6: {gateway}");
}

debug!("Adding peer routing for interface: {ifname}");
Expand Down