oncrpc

Documentation

Overview

Package oncrpc parses the ONC RPC (Sun RPC, RFC 5531) message header shared by the project's RPC-protocol decoders — internal/portmap (rpcbind), internal/mount (NFS MOUNT) and internal/nfs (NFS v3). Each of those decodes the same call/reply framing (transaction id, message type, the call program/version/procedure + auth/verifier, or the reply accept status) before its procedure-specific body; this package owns that framing once so the protocol decoders only implement their own procedure bodies.

Wrap-vs-native judgement

Native. The RPC message header is a short sequence of 32-bit XDR
fields with two variable-length auth/verifier opaque blobs — a
byte-field read with bounds checks. stdlib only, no new go.mod dep.

Scope

The message header only: the transaction id, the call fields
(rpcvers / program / version / procedure / auth flavor, skipping the
auth + verifier opaque bodies) or the reply fields (reply status,
and for an accepted reply the accept status), and the byte offset of
the procedure-specific Body. The body itself is decoded by the
per-program packages. RPCSEC_GSS auth bodies are skipped by their
declared length like any other flavor.

Index

• func AcceptStatName(s uint32) string
• type Message
  • func Parse(b []byte) (*Message, error)
  • func (m *Message) IsCall() bool
  • func (m *Message) IsReply() bool

Functions

func AcceptStatName

func AcceptStatName(s uint32) string

AcceptStatName maps the RFC 5531 accept_stat enumeration.

Types

type Message

type Message struct {
	XID  uint32
	Type uint32 // 0 = CALL, 1 = REPLY

	// CALL fields (valid when Type == 0).
	RPCVersion     uint32
	Program        uint32
	ProgramVersion uint32
	Procedure      uint32
	AuthFlavor     uint32

	// REPLY fields (valid when Type == 1).
	ReplyStat  uint32 // 0 = MSG_ACCEPTED, 1 = MSG_DENIED
	Accepted   bool
	AcceptStat uint32 // valid when Accepted

	// Body is the procedure arguments (CALL), the accepted result (REPLY,
	// after the accept status), or the reject info (a denied REPLY).
	Body []byte
}

Message is a parsed ONC RPC message header with the procedure-specific body isolated in Body.

func Parse

func Parse(b []byte) (*Message, error)

Parse decodes the ONC RPC message header from b (the RPC payload without any TCP record marker) and isolates the procedure-specific body.

func (*Message) IsCall

func (m *Message) IsCall() bool

IsCall reports whether the message is an RPC CALL.

func (*Message) IsReply

func (m *Message) IsReply() bool

IsReply reports whether the message is an RPC REPLY.