Struct NetStackBuilder 

pub struct NetStackBuilder { /* private fields */ }

Builder for a NetStack.

The defaults follow the established userspace-networking convention: IPv4 and IPv6 both enabled, the guest at 10.0.2.15/24 and fd00::15/64, the gateway — the stack itself — at 10.0.2.2 and fd00::2, MTU 1500, interface tap0. Within a configured network the stack always places the gateway at host 2 and the guest at host 15.

With the serde feature the builder serializes and deserializes as the stack specification, for embedding in a consumer’s own configuration. Keys are kebab-case; unknown keys are rejected; the CIDR fields read and write as strings. In TOML:

ipv4-cidr = "10.0.2.0/24"
ipv6 = false
mtu = 1500
interface = "tap0"

Implementations

impl NetStackBuilder

pub fn ipv4(self, enabled: bool) -> Self

Enables or disables IPv4. Enabled by default.

pub fn ipv6(self, enabled: bool) -> Self

Enables or disables IPv6. Enabled by default.

pub fn ipv4_cidr(self, network: Ipv4Addr, prefix_len: u8) -> Self

Sets the IPv4 network. The default is 10.0.2.0/24.

network must be the network address itself — no bits set past the prefix — and the prefix length must be between 1 and 27, leaving room for the gateway at host 2 and the guest at host 15. Validated by build.

pub fn ipv6_cidr(self, network: Ipv6Addr, prefix_len: u8) -> Self

Sets the IPv6 network. The default is fd00::/64.

network must be the network address itself and the prefix length must be between 1 and 120, leaving the address plan the final byte. Validated by build.

pub fn mtu(self, mtu: u16) -> Self

Sets the tap interface’s MTU. The default is 1500.

The minimum is 576, or 1280 while IPv6 is enabled. Validated by build.

pub fn interface(self, name: impl Into<String>) -> Self

Names the tap interface inside the sandbox. The default is tap0.

The name must satisfy the kernel’s interface-name rules: 1 to 15 bytes, not . or .., and free of /, :, and whitespace. Validated by build.

pub fn host_loopback(self, enabled: bool) -> Self

Maps connections to the gateway address onto host loopback. Off by default.

The stack never forwards guest traffic to the host’s loopback addresses: 127.0.0.0/8 and ::1 destinations are refused outright. With this option, a connection to the gateway address (10.0.2.2 and fd00::2 by default) is instead forwarded to 127.0.0.1 or ::1 on the host, port preserved — the conventional way to reach a host-local service from inside the sandbox, granted deliberately rather than by making the whole loopback range reachable.

pub fn build(self) -> Result<NetStack, NetStackError>

Validates the configuration and freezes it into a NetStack.

Trait Implementations

impl Clone for NetStackBuilder

fn clone(&self) -> NetStackBuilder

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for NetStackBuilder

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

Formats the value using the given formatter.

impl Default for NetStackBuilder

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for NetStackBuilder

where NetStackBuilder: Default,

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for NetStackBuilder

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.