Struct IpAllocator 

pub struct IpAllocator { /* private fields */ }

IP allocator for overlay network addresses

Tracks allocated IP addresses and provides next-available allocation from a configured CIDR range. Supports both IPv4 and IPv6 networks.

Implementations

impl IpAllocator

pub fn new(cidr: &str) -> Result<Self>

Create a new IP allocator for the given CIDR range

Supports both IPv4 (e.g., “10.200.0.0/16”) and IPv6 (e.g., fd00::/48).

Arguments

• cidr - Network CIDR notation

Errors

Returns OverlayError::InvalidCidr if the CIDR string cannot be parsed.

Example

use zlayer_overlay::allocator::IpAllocator;

let v4 = IpAllocator::new("10.200.0.0/16").unwrap();
let v6 = IpAllocator::new("fd00::/48").unwrap();

pub fn from_state(state: IpAllocatorState) -> Result<Self>

Create an allocator from persisted state

Errors

Returns an error if the CIDR is invalid or any IP is out of range.

pub fn to_state(&self) -> IpAllocatorState

Get the current state for persistence

pub async fn load(path: &Path) -> Result<Self>

Load allocator state from a file

Errors

Returns an error if the file cannot be read or the state is invalid.

pub async fn save(&self, path: &Path) -> Result<()>

Save allocator state to a file

Errors

Returns an error if the file cannot be written or serialization fails.

pub fn allocate(&mut self) -> Option<IpAddr>

Allocate the next available IP address

For IPv4, skips the network and broadcast addresses. For IPv6, skips the network address.

Returns None if all addresses in the CIDR range are allocated.

Example

use zlayer_overlay::allocator::IpAllocator;

let mut allocator = IpAllocator::new("10.200.0.0/24").unwrap();
let ip = allocator.allocate().unwrap();
assert_eq!(ip.to_string(), "10.200.0.1");

pub fn allocate_specific(&mut self, ip: IpAddr) -> Result<()>

Allocate a specific IP address

Errors

Returns an error if the IP is already allocated or not in the CIDR range.

pub fn allocate_first(&mut self) -> Result<IpAddr>

Allocate the first usable IP in the range (typically for the leader)

Example

use zlayer_overlay::allocator::IpAllocator;

let mut allocator = IpAllocator::new("10.200.0.0/24").unwrap();
let ip = allocator.allocate_first().unwrap();
assert_eq!(ip.to_string(), "10.200.0.1");

Errors

Returns an error if no IPs are available or the first IP is already allocated.

pub fn mark_allocated(&mut self, ip: IpAddr) -> Result<()>

Mark an IP address as allocated (for restoring state)

Errors

Returns an error if the IP is not in the CIDR range.

pub fn release(&mut self, ip: IpAddr) -> bool

Release an IP address back to the pool

Returns true if the IP was released, false if it wasn’t allocated.

pub fn is_allocated(&self, ip: IpAddr) -> bool

Check if an IP address is allocated

pub fn contains(&self, ip: IpAddr) -> bool

Check if an IP address is within the CIDR range

pub fn allocated_count(&self) -> usize

Get the number of allocated addresses

pub fn total_hosts(&self) -> u32

Get the total number of usable addresses in the range

For IPv6 networks with large host spaces, this saturates at u32::MAX.

pub fn available_count(&self) -> u32

Get the number of available addresses

pub fn cidr(&self) -> String

Get the CIDR string

pub fn network_addr(&self) -> IpAddr

Get the network address

pub fn broadcast_addr(&self) -> IpAddr

Get the broadcast address

For IPv6, returns the last address in the range (all host bits set to 1).

pub fn prefix_len(&self) -> u8

Get the prefix length

pub fn host_prefix_len(&self) -> u8

Get the host prefix length (32 for IPv4, 128 for IPv6)

pub fn allocated_ips(&self) -> Vec<IpAddr>

Get all allocated IPs

Trait Implementations

impl Clone for IpAllocator

fn clone(&self) -> IpAllocator

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for IpAllocator

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.