Module headers 

Typed header values.

Headers are parsed on demand, never during message parsing. A message with a malformed CSeq frames and forwards perfectly well; only a party that needs to read CSeq has a problem, and it finds out by asking:

match message.headers().typed::<CSeq>() {
    None => { /* absent */ }
    Some(Err(_)) => { /* present and malformed — answer 400 */ }
    Some(Ok(cseq)) => { /* usable */ }
}

The Option<Result<..>> is deliberate. Collapsing it is how implementations end up treating a corrupt header as a missing one.

Authentication headers are not here: they belong to the user-agent layer, which is where anything that can act on a challenge lives.

Re-exports

pub use address::Address;

pub use address::Contact;

pub use address::ContactValue;

pub use address::From;

pub use address::RecordRoute;

pub use address::Route;

pub use address::To;

pub use history::HistoryEntry;

pub use history::HistoryIndex;

pub use history::HistoryInfo;

pub use history::Reason;

pub use history::ReasonValue;

pub use history::TargetChange;

pub use history::TargetChangeKind;

pub use identity::IgnoredIdentity;

pub use identity::IgnoredIdentityReason;

pub use identity::PAssertedIdentity;

pub use identity::PAssertedIdentityList;

pub use identity::PPreferredIdentity;

pub use identity::PPreferredIdentityList;

pub use misc::Allow;

pub use misc::CSeq;

pub use misc::CallId;

pub use misc::ContentLength;

pub use misc::ContentType;

pub use misc::Date;

pub use misc::Expires;

pub use misc::MaxForwards;

pub use misc::ProxyRequire;

pub use misc::Require;

pub use misc::Supported;

pub use misc::TokenList;

pub use misc::Unsupported;

pub use privacy::Privacy;

pub use privacy::PrivacyList;

pub use privacy::PrivacyValue;

pub use via::BRANCH_MAGIC_COOKIE;

pub use via::OcParameter;

pub use via::OverloadAlgorithm;

pub use via::OverloadSequence;

pub use via::Via;

pub use via::ViaOverload;

pub use via::first_hop_end;

Modules

address

Address headers: From, To, Contact, Route, Record-Route, Refer-To.

history

Diversion history and call reasons (RFC 7044 and RFC 3326).

identity

RFC 3325 asserted and preferred identity header values.

misc

The remaining headers the core needs: CSeq, Call-ID, the scalars, Content-Type, Date, and the token-list headers.

privacy

Privacy preferences (RFC 3323 §4.2 and verified erratum 5184).

via

The Via header (RFC 3261 §20.42).

Structs

HeaderParam

One header parameter: name or name=value, where the value may be quoted.