Struct ClientVersionPolicy 

pub struct ClientVersionPolicy { /* private fields */ }

Available on crate feature quic only.

How a client picks its first flight’s version and what it lets the server negotiate (RFC 9368 §2.5, §3).

The default starts in Version::V1, lets a server move the connection to Version::V2 without a round trip, and restarts in either version if the server answers with a Version Negotiation packet. A TLS provider that cannot change version during the handshake narrows the compatible set to the original version.

Implementations

impl ClientVersionPolicy

pub fn new(original: Version) -> Result<ClientVersionPolicy, VersionPolicyError>

Start in original and offer nothing else: no compatible switch and no restart.

pub fn original(&self) -> Version

The version of the first flight.

pub fn compatible(&self) -> &[Version]

The versions the first flight is compatible with, most preferred first. A server may move the connection to any of them during the handshake.

pub fn supported(&self) -> &[Version]

The versions a new first flight may use after a Version Negotiation packet, most preferred first.

pub fn reserved_version_grease(&self) -> ReservedVersionGrease

Whether, and where, a reserved version is added to the advertised list (RFC 9368 §3).

pub fn needs_switch(&self) -> bool

Whether this policy may need the TLS session to change version mid-handshake.

pub fn try_with_compatible( self, compatible: Vec<Version>, ) -> Result<ClientVersionPolicy, VersionPolicyError>

The versions the first flight is compatible with; must contain the original and only versions compatible with it.

pub fn try_with_supported( self, supported: Vec<Version>, ) -> Result<ClientVersionPolicy, VersionPolicyError>

The versions a restart after Version Negotiation may pick from; must contain the original.

pub fn with_reserved_version_grease( self, grease: ReservedVersionGrease, ) -> ClientVersionPolicy

Whether, and where, to add a reserved version to the advertised compatible list. Last by default.

pub fn set_reserved_version_grease( &mut self, grease: ReservedVersionGrease, ) -> &mut ClientVersionPolicy

Whether, and where, to add a reserved version to the advertised compatible list. Last by default.

pub fn with_resume_in_ticket_version(self, resume: bool) -> ClientVersionPolicy

Whether a first flight to a server that issued a session ticket in another supported version starts in that version, so the ticket can resume it (RFC 9369 §5, §6). On for the default policy; off once a first flight version is chosen explicitly, until turned on again here.

pub fn set_resume_in_ticket_version( &mut self, resume: bool, ) -> &mut ClientVersionPolicy

Whether a first flight to a server that issued a session ticket in another supported version starts in that version, so the ticket can resume it (RFC 9369 §5, §6). On for the default policy; off once a first flight version is chosen explicitly, until turned on again here.

pub fn resumes_in_ticket_version(&self) -> bool

Whether a first flight follows the version of a held session ticket.

pub fn for_ticket(&self, ticket: Option<Version>) -> ClientVersionPolicy

The policy for an attempt to a server that issued a ticket in ticket: the same policy starting in that version when it is supported and following tickets is on.

pub fn with_original( self, original: Version, ) -> Result<ClientVersionPolicy, VersionPolicyError>

Start in original, keeping the rest of the policy and adding original to its lists.

pub fn narrowed_public(self) -> ClientVersionPolicy

The same policy with no compatible version other than the original, so no switch is needed. A backend that cannot change version mid-handshake uses this.

pub fn narrowed(self) -> ClientVersionPolicy

The same policy without a compatible switch, for a TLS session that cannot change version.

pub fn all_versions(&self) -> impl Iterator<Item = Version>

Every version the endpoint must be able to decode for this policy.

pub fn select(&self, offered: &[Version]) -> Option<Version>

The version this client would pick from a server’s list, by its own preference order, ignoring reserved versions (RFC 9368 §2.1, §4).

pub fn information(&self, grease: Version) -> VersionInformation

What the client advertises: its original version and, in preference order, what the first flight is compatible with.

Trait Implementations

impl Clone for ClientVersionPolicy

fn clone(&self) -> ClientVersionPolicy

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ClientVersionPolicy

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

Formats the value using the given formatter.

impl Default for ClientVersionPolicy

fn default() -> ClientVersionPolicy

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for ClientVersionPolicy

fn deserialize<__D>( __deserializer: __D, ) -> Result<ClientVersionPolicy, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for ClientVersionPolicy

impl PartialEq for ClientVersionPolicy

fn eq(&self, other: &ClientVersionPolicy) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for ClientVersionPolicy

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for ClientVersionPolicy

impl TryFrom<ClientVersionPolicyRepr> for ClientVersionPolicy

type Error = VersionPolicyError

The type returned in the event of a conversion error.

fn try_from( repr: ClientVersionPolicyRepr, ) -> Result<ClientVersionPolicy, <ClientVersionPolicy as TryFrom<ClientVersionPolicyRepr>>::Error>

Performs the conversion.