transport

type Address struct {
	Addr string
}

type BoundEndpoint interface {
	// BidirectionalConnect establishes a bi-directional connection between two
	// unix endpoints in an all-or-nothing manner. If an error occurs during
	// connecting, the state of neither endpoint should be modified.
	//
	// In order for an endpoint to establish such a bidirectional connection
	// with a BoundEndpoint, the endpoint calls the BidirectionalConnect method
	// on the BoundEndpoint and sends a representation of itself (the
	// ConnectingEndpoint) and a callback (returnConnect) to receive the
	// connection information (Receiver and ConnectedEndpoint) upon a
	// successful connect. The callback should only be called on a successful
	// connect.
	//
	// For a connection attempt to be successful, the ConnectingEndpoint must
	// be unconnected and not listening and the BoundEndpoint whose
	// BidirectionalConnect method is being called must be listening.
	//
	// This method will return syserr.ErrConnectionRefused on endpoints with a
	// type that isn't SockStream or SockSeqpacket.
	BidirectionalConnect(ctx context.Context, ep ConnectingEndpoint, returnConnect func(Receiver, ConnectedEndpoint)) *syserr.Error

	// UnidirectionalConnect establishes a write-only connection to a unix
	// endpoint.
	//
	// An endpoint which calls UnidirectionalConnect and supports it itself must
	// not hold its own lock when calling UnidirectionalConnect.
	//
	// This method will return syserr.ErrConnectionRefused on a non-SockDgram
	// endpoint.
	UnidirectionalConnect(ctx context.Context) (ConnectedEndpoint, *syserr.Error)

	// Passcred returns whether or not the SO_PASSCRED socket option is
	// enabled on this end.
	Passcred() bool

	// Release releases any resources held by the BoundEndpoint. It must be
	// called before dropping all references to a BoundEndpoint returned by a
	// function.
	Release(ctx context.Context)
}

type BoundSocketFD interface {
	// Close closes the socket FD.
	Close(ctx context.Context)

	// NotificationFD is a host FD that can be used to notify when new clients
	// connect to the socket.
	NotificationFD() int32

	// Listen is analogous to listen(2).
	Listen(ctx context.Context, backlog int32) error

	// Accept is analogous to accept(2).
	Accept(ctx context.Context) (int, error)
}

type ConnectedEndpoint interface {
	// Passcred implements Endpoint.Passcred.
	Passcred() bool

	// GetLocalAddress implements Endpoint.GetLocalAddress.
	GetLocalAddress() (Address, tcpip.Error)

	// Send sends a single message. This method does not block.
	//
	// notify indicates if SendNotify should be called.
	//
	// syserr.ErrWouldBlock can be returned along with a partial write if
	// the caller should block to send the rest of the data.
	Send(ctx context.Context, data [][]byte, c ControlMessages, from Address) (n int64, notify bool, err *syserr.Error)

	// SendNotify notifies the ConnectedEndpoint of a successful Send. This
	// must not be called while holding any endpoint locks.
	SendNotify()

	// CloseSend prevents the sending of additional Messages.
	//
	// After CloseSend is call, CloseNotify must also be called.
	CloseSend()

	// CloseNotify notifies the ConnectedEndpoint of send being closed. This
	// must not be called while holding any endpoint locks.
	CloseNotify()

	// IsSendClosed returns true if transmission of additional messages is closed.
	IsSendClosed() bool

	// Writable returns if messages should be attempted to be sent. This
	// includes when write has been shutdown.
	Writable() bool

	// EventUpdate lets the ConnectedEndpoint know that event registrations
	// have changed.
	EventUpdate() error

	// SendQueuedSize returns the total amount of data currently queued for
	// sending. SendQueuedSize should return -1 if the operation isn't
	// supported.
	SendQueuedSize() int64

	// SendMaxQueueSize returns maximum value for SendQueuedSize.
	// SendMaxQueueSize should return -1 if the operation isn't supported.
	SendMaxQueueSize() int64

	// Release releases any resources owned by the ConnectedEndpoint. It should
	// be called before dropping all references to a ConnectedEndpoint.
	Release(ctx context.Context)

	// CloseUnread sets the fact that this end is closed with unread data to
	// the peer socket.
	CloseUnread()

	// SetSendBufferSize is called when the endpoint's send buffer size is
	// changed.
	SetSendBufferSize(v int64) (newSz int64)
}

type ConnectingEndpoint interface {
	// ID returns the endpoint's globally unique identifier. This identifier
	// must be used to determine locking order if more than one endpoint is
	// to be locked in the same codepath. The endpoint with the smaller
	// identifier must be locked before endpoints with larger identifiers.
	ID() uint64

	// Passcred implements socket.Credentialer.Passcred.
	Passcred() bool

	// Type returns the socket type, typically either SockStream or
	// SockSeqpacket. The connection attempt must be aborted if this
	// value doesn't match the BoundEndpoint's type.
	Type() linux.SockType

	// GetLocalAddress returns the bound path.
	GetLocalAddress() (Address, tcpip.Error)

	// Connected returns true iff the ConnectingEndpoint is in the connected
	// state. ConnectingEndpoints can only be connected to a single endpoint,
	// so the connection attempt must be aborted if this returns true.
	Connected() bool

	// ListeningLocked returns true iff the ConnectingEndpoint is in the
	// listening state. ConnectingEndpoints cannot make connections while
	// listening, so the connection attempt must be aborted if this returns
	// true.
	ListeningLocked() bool

	// WaiterQueue returns a pointer to the endpoint's waiter queue.
	WaiterQueue() *waiter.Queue
	// contains filtered or unexported methods
}

type ControlMessages struct {
	// Rights is a control message containing FDs.
	Rights RightsControlMessage

	// Credentials is a control message containing Unix credentials.
	Credentials CredentialsControlMessage
}

type Credentialer interface {
	// Passcred returns whether or not the SO_PASSCRED socket option is
	// enabled on this end.
	Passcred() bool

	// ConnectedPasscred returns whether or not the SO_PASSCRED socket option
	// is enabled on the connected end.
	ConnectedPasscred() bool
}

type CredentialsControlMessage interface {
	// Equals returns true iff the two messages are equal.
	Equals(CredentialsControlMessage) bool
}

type Endpoint interface {
	Credentialer
	waiter.Waitable

	// Close puts the endpoint in a closed state and frees all resources
	// associated with it.
	Close(ctx context.Context)

	// RecvMsg reads data and a control message from the endpoint. This method
	// does not block if there is no data pending.
	//
	// The returned callback should be called if not nil.
	RecvMsg(ctx context.Context, data [][]byte, args RecvArgs) (RecvOutput, func(), *syserr.Error)

	// SendMsg writes data and a control message to the endpoint's peer.
	// This method does not block if the data cannot be written.
	//
	// SendMsg does not take ownership of any of its arguments on error.
	//
	// If set, notify is a callback that should be called after RecvMesg
	// completes without mm.activeMu held.
	SendMsg(context.Context, [][]byte, ControlMessages, BoundEndpoint) (int64, func(), *syserr.Error)

	// Connect connects this endpoint directly to another.
	//
	// This should be called on the client endpoint, and the (bound)
	// endpoint passed in as a parameter.
	//
	// The error codes are the same as Connect.
	Connect(ctx context.Context, server BoundEndpoint) *syserr.Error

	// Shutdown closes the read and/or write end of the endpoint connection
	// to its peer.
	Shutdown(flags tcpip.ShutdownFlags) *syserr.Error

	// Listen puts the endpoint in "listen" mode, which allows it to accept
	// new connections.
	Listen(ctx context.Context, backlog int) *syserr.Error

	// Accept returns a new endpoint if a peer has established a connection
	// to an endpoint previously set to listen mode. This method does not
	// block if no new connections are available.
	//
	// The returned Queue is the wait queue for the newly created endpoint.
	//
	// peerAddr if not nil will be populated with the address of the connected
	// peer on a successful accept.
	Accept(ctx context.Context, peerAddr *Address) (Endpoint, *syserr.Error)

	// Bind binds the endpoint to a specific local address and port.
	// Specifying a NIC is optional.
	Bind(address Address) *syserr.Error

	// Type return the socket type, typically either SockStream, SockDgram
	// or SockSeqpacket.
	Type() linux.SockType

	// GetLocalAddress returns the address to which the endpoint is bound.
	GetLocalAddress() (Address, tcpip.Error)

	// GetRemoteAddress returns the address to which the endpoint is
	// connected.
	GetRemoteAddress() (Address, tcpip.Error)

	// SetSockOpt sets a socket option.
	SetSockOpt(opt tcpip.SettableSocketOption) tcpip.Error

	// SetSockOptInt sets a socket option for simple cases when a value has
	// the int type.
	SetSockOptInt(opt tcpip.SockOptInt, v int) tcpip.Error

	// GetSockOpt gets a socket option.
	GetSockOpt(opt tcpip.GettableSocketOption) tcpip.Error

	// GetSockOptInt gets a socket option for simple cases when a return
	// value has the int type.
	GetSockOptInt(opt tcpip.SockOptInt) (int, tcpip.Error)

	// State returns the current state of the socket, as represented by Linux in
	// procfs.
	State() uint32

	// LastError clears and returns the last error reported by the endpoint.
	LastError() tcpip.Error

	// SocketOptions returns the structure which contains all the socket
	// level options.
	SocketOptions() *tcpip.SocketOptions
}

type HostBoundEndpoint interface {
	// SetBoundSocketFD will be called on supporting endpoints after
	// binding a socket on the host filesystem. Implementations should
	// delegate Listen and Accept calls to the BoundSocketFD. The ownership
	// of bsFD is transferred to the endpoint.
	SetBoundSocketFD(ctx context.Context, bsFD BoundSocketFD) error

	// ResetBoundSocketFD cleans up the BoundSocketFD set by the last successful
	// SetBoundSocketFD call.
	ResetBoundSocketFD(ctx context.Context)
}

type HostConnectedEndpoint struct {
	HostConnectedEndpointRefs
	// contains filtered or unexported fields
}

type Receiver interface {
	// Recv receives a single message. This method does not block.
	//
	// notify indicates if RecvNotify should be called.
	Recv(ctx context.Context, data [][]byte, args RecvArgs) (out RecvOutput, notify bool, err *syserr.Error)

	// RecvNotify notifies the Receiver of a successful Recv. This must not be
	// called while holding any endpoint locks.
	RecvNotify()

	// CloseRecv prevents the receiving of additional Messages.
	//
	// After CloseRecv is called, CloseNotify must also be called.
	CloseRecv()

	// CloseNotify notifies the Receiver of recv being closed. This must not be
	// called while holding any endpoint locks.
	CloseNotify()

	// IsRecvClosed returns true if reception of additional messages is closed.
	IsRecvClosed() bool

	// Readable returns if messages should be attempted to be received. This
	// includes when read has been shutdown.
	Readable() bool

	// RecvQueuedSize returns the total amount of data currently receivable.
	// RecvQueuedSize should return -1 if the operation isn't supported.
	RecvQueuedSize() int64

	// RecvMaxQueueSize returns maximum value for RecvQueuedSize.
	// RecvMaxQueueSize should return -1 if the operation isn't supported.
	RecvMaxQueueSize() int64

	// Release releases any resources owned by the Receiver. It should be
	// called before dropping all references to a Receiver.
	Release(ctx context.Context)
}

type RecvArgs struct {
	// Creds indicates if credential control messages are requested by the
	// caller. This is useful for determining if control messages can be
	// coalesced. Creds is a hint and can be safely ignored by the
	// implementation if no coalescing is possible. It is fine to return
	// credential control messages when none were requested or to not
	// return credential control messages when they were requested.
	Creds bool

	// NumRights is the number of SCM_RIGHTS FDs requested by the caller.
	// This is useful if one must allocate a buffer to receive a SCM_RIGHTS
	// message or determine if control messages can be coalesced. numRights
	// is a hint and can be safely ignored by the implementation if the
	// number of available SCM_RIGHTS FDs is known and no coalescing is
	// possible. It is fine for the returned number of SCM_RIGHTS FDs to be
	// either higher or lower than the requested number.
	NumRights int

	// If Peek is true, no data should be consumed from the Endpoint. Any and
	// all data returned from a peek should be available in the next call to
	// Recv or RecvMsg.
	Peek bool
}

type RecvOutput struct {
	// RecvLen is the number of bytes copied into RecvArgs.Data.
	RecvLen int64

	// MsgLen is the length of the read message consumed for datagram Endpoints.
	// MsgLen is always the same as RecvLen for stream Endpoints.
	MsgLen int64

	// Source is the source address we received from.
	Source Address

	// Control is the ControlMessages read.
	Control ControlMessages

	// ControlTrunc indicates that the NumRights hint was used to receive
	// fewer than the total available SCM_RIGHTS FDs. Additional truncation
	// may be required by the caller.
	ControlTrunc bool

	// UnusedRights is a slice of unused RightsControlMessage which should
	// be Release()d.
	UnusedRights []RightsControlMessage
}

type RightsControlMessage interface {
	// Clone returns a copy of the RightsControlMessage.
	Clone() RightsControlMessage

	// Release releases any resources owned by the RightsControlMessage.
	Release(ctx context.Context)
}

type SCMConnectedEndpoint struct {
	HostConnectedEndpoint
	// contains filtered or unexported fields
}

type SCMRights struct {
	FDs []int
}