Skip to content

Subnet broadcasts #377

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Jan 16, 2021
Merged

Subnet broadcasts #377

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
53 changes: 51 additions & 2 deletions src/iface/ethernet.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1023,7 +1023,9 @@ impl<'b, 'c, 'e> InterfaceInner<'b, 'c, 'e> {

if !self.has_ip_addr(ipv4_repr.dst_addr) &&
!ipv4_repr.dst_addr.is_broadcast() &&
!self.has_multicast_group(ipv4_repr.dst_addr) {
!self.has_multicast_group(ipv4_repr.dst_addr) &&
!self.is_subnet_broadcast(ipv4_repr.dst_addr) {

// Ignore IP packets not directed at us, or broadcast, or any of the multicast groups.
// If AnyIP is enabled, also check if the packet is routed locally.
if !self.any_ip ||
Expand Down Expand Up @@ -1066,6 +1068,19 @@ impl<'b, 'c, 'e> InterfaceInner<'b, 'c, 'e> {
}
}

/// Checks if an incoming packet has a broadcast address for the interfaces
/// associated ipv4 addresses.
#[cfg(feature = "proto-ipv4")]
fn is_subnet_broadcast(&self, address: Ipv4Address) -> bool {
self.ip_addrs.iter()
.filter_map(|own_cidr| match own_cidr {
IpCidr::Ipv4(own_ip) => Some(own_ip.broadcast()?),
#[cfg(feature = "proto-ipv6")]
IpCidr::Ipv6(_) => None
})
.any(|broadcast_address| address == broadcast_address)
}

/// Host duties of the **IGMPv2** protocol.
///
/// Sets up `igmp_report_state` for responding to IGMP general/specific membership queries.
Expand Down Expand Up @@ -1695,7 +1710,7 @@ mod test {
use crate::wire::{EthernetAddress, EthernetFrame, EthernetProtocol};
use crate::wire::{IpAddress, IpCidr, IpProtocol, IpRepr};
#[cfg(feature = "proto-ipv4")]
use crate::wire::{Ipv4Address, Ipv4Repr};
use crate::wire::{Ipv4Address, Ipv4Repr, Ipv4Cidr};
#[cfg(feature = "proto-igmp")]
use crate::wire::Ipv4Packet;
#[cfg(feature = "proto-ipv4")]
Expand Down Expand Up @@ -1875,6 +1890,40 @@ mod test {
Ok(Some(expected_repr)));
}

#[test]
#[cfg(feature = "proto-ipv4")]
fn test_local_subnet_broadcasts() {
let (mut iface, _) = create_loopback();
iface.update_ip_addrs(|addrs| {
addrs.iter_mut().next().map(|addr| {
*addr = IpCidr::Ipv4(Ipv4Cidr::new(Ipv4Address([192, 168, 1, 23]), 24));
});
});

assert_eq!(iface.inner.is_subnet_broadcast(Ipv4Address([192, 168, 1, 255])), true);
assert_eq!(iface.inner.is_subnet_broadcast(Ipv4Address([192, 168, 1, 254])), false);

iface.update_ip_addrs(|addrs| {
addrs.iter_mut().next().map(|addr| {
*addr = IpCidr::Ipv4(Ipv4Cidr::new(Ipv4Address([192, 168, 23, 24]), 16));
});
});
assert_eq!(iface.inner.is_subnet_broadcast(Ipv4Address([192, 168, 23, 255])), false);
assert_eq!(iface.inner.is_subnet_broadcast(Ipv4Address([192, 168, 23, 254])), false);
assert_eq!(iface.inner.is_subnet_broadcast(Ipv4Address([192, 168, 255, 254])), false);
assert_eq!(iface.inner.is_subnet_broadcast(Ipv4Address([192, 168, 255, 255])), true);

iface.update_ip_addrs(|addrs| {
addrs.iter_mut().next().map(|addr| {
*addr = IpCidr::Ipv4(Ipv4Cidr::new(Ipv4Address([192, 168, 23, 24]), 8));
});
});
assert_eq!(iface.inner.is_subnet_broadcast(Ipv4Address([192, 23, 1, 255])), false);
assert_eq!(iface.inner.is_subnet_broadcast(Ipv4Address([192, 23, 1, 254])), false);
assert_eq!(iface.inner.is_subnet_broadcast(Ipv4Address([192, 255, 255, 254])), false);
assert_eq!(iface.inner.is_subnet_broadcast(Ipv4Address([192, 255, 255, 255])), true);
}

#[test]
#[cfg(all(feature = "socket-udp", feature = "proto-ipv4"))]
fn test_icmp_error_port_unreachable() {
Expand Down