netlink

package
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Published: Dec 29, 2021 License: Apache-2.0, MIT Imports: 29 Imported by: 0

Documentation

Overview

Package netlink provides core functionality for netlink sockets.

Index

Constants

This section is empty.

Variables

This section is empty.

Functions

func ExtractSockAddr

func ExtractSockAddr(b []byte) (*linux.SockAddrNetlink, *syserr.Error)

ExtractSockAddr extracts the SockAddrNetlink from b.

func RegisterProvider

func RegisterProvider(protocol int, provider Provider)

RegisterProvider registers the provider of a given address protocol so that netlink sockets of that type can be created via socket(2).

Preconditions: May only be called before any netlink sockets are created.

Types

type AttrsView

type AttrsView []byte

AttrsView is a view into the attributes portion of a netlink message.

func (AttrsView) Empty

func (v AttrsView) Empty() bool

Empty returns whether there is no attribute left in v.

func (AttrsView) ParseFirst

func (v AttrsView) ParseFirst() (hdr linux.NetlinkAttrHeader, value []byte, rest AttrsView, ok bool)

ParseFirst parses first netlink attribute at the beginning of v.

type BytesView

type BytesView []byte

BytesView supports extracting data from a byte slice with bounds checking.

func (*BytesView) Extract

func (v *BytesView) Extract(n int) ([]byte, bool)

Extract removes the first n bytes from v and returns it. If n is out of bounds, it returns false.

type Message

type Message struct {
	// contains filtered or unexported fields
}

Message contains a complete serialized netlink message.

func NewMessage

func NewMessage(hdr linux.NetlinkMessageHeader) *Message

NewMessage creates a new Message containing the passed header.

The header length will be updated by Finalize.

func ParseMessage

func ParseMessage(buf []byte) (msg *Message, rest []byte, ok bool)

ParseMessage parses the first message seen at buf, returning the rest of the buffer. If message is malformed, ok of false is returned. For last message, padding check is loose, if there isn't enought padding, whole buf is consumed and ok is set to true.

func (*Message) Finalize

func (m *Message) Finalize() []byte

Finalize returns the []byte containing the entire message, with the total length set in the message header. The Message must not be modified after calling Finalize.

func (*Message) GetData

func (m *Message) GetData(msg marshal.Marshallable) (AttrsView, bool)

GetData unmarshals the payload message header from this netlink message, and returns the attributes portion.

func (*Message) Header

func (m *Message) Header() linux.NetlinkMessageHeader

Header returns the header of this message.

func (*Message) Put

func (m *Message) Put(v marshal.Marshallable)

Put serializes v into the message.

func (*Message) PutAttr

func (m *Message) PutAttr(atype uint16, v marshal.Marshallable)

PutAttr adds v to the message as a netlink attribute.

Preconditions: The serialized attribute (linux.NetlinkAttrHeaderSize + v.SizeBytes()) fits in math.MaxUint16 bytes.

func (*Message) PutAttrString

func (m *Message) PutAttrString(atype uint16, s string)

PutAttrString adds s to the message as a netlink attribute.

type MessageSet

type MessageSet struct {
	// Multi indicates that this a multi-part message, to be terminated by
	// NLMSG_DONE. NLMSG_DONE is sent even if the set contains only one
	// Message.
	//
	// If Multi is set, all added messages will have NLM_F_MULTI set.
	Multi bool

	// PortID is the destination port for all messages.
	PortID int32

	// Seq is the sequence counter for all messages in the set.
	Seq uint32

	// Messages contains the messages in the set.
	Messages []*Message
}

MessageSet contains a series of netlink messages.

func NewMessageSet

func NewMessageSet(portID int32, seq uint32) *MessageSet

NewMessageSet creates a new MessageSet.

portID is the destination port to set as PortID in all messages.

seq is the sequence counter to set as seq in all messages in the set.

func (*MessageSet) AddMessage

func (ms *MessageSet) AddMessage(hdr linux.NetlinkMessageHeader) *Message

AddMessage adds a new message to the set and returns it for further additions.

The passed header will have Seq, PortID and the multi flag set automatically.

type Protocol

type Protocol interface {
	// Protocol returns the Linux netlink protocol value.
	Protocol() int

	// CanSend returns true if this protocol may ever send messages.
	//
	// TODO(gvisor.dev/issue/1119): This is a workaround to allow
	// advertising support for otherwise unimplemented features on sockets
	// that will never send messages, thus making those features no-ops.
	CanSend() bool

	// ProcessMessage processes a single message from userspace.
	//
	// If err == nil, any messages added to ms will be sent back to the
	// other end of the socket. Setting ms.Multi will cause an NLMSG_DONE
	// message to be sent even if ms contains no messages.
	ProcessMessage(ctx context.Context, msg *Message, ms *MessageSet) *syserr.Error
}

Protocol is the implementation of a netlink socket protocol.

type Provider

type Provider func(t *kernel.Task) (Protocol, *syserr.Error)

Provider is a function that creates a new Protocol for a specific netlink protocol.

Note that this is distinct from socket.Provider, which is used for all socket families.

type Socket

type Socket struct {
	fsutil.FilePipeSeek             `state:"nosave"`
	fsutil.FileNotDirReaddir        `state:"nosave"`
	fsutil.FileNoFsync              `state:"nosave"`
	fsutil.FileNoMMap               `state:"nosave"`
	fsutil.FileNoSplice             `state:"nosave"`
	fsutil.FileNoopFlush            `state:"nosave"`
	fsutil.FileUseInodeUnstableAttr `state:"nosave"`
	// contains filtered or unexported fields
}

Socket is the base socket type for netlink sockets.

This implementation only supports userspace sending and receiving messages to/from the kernel.

Socket implements socket.Socket and transport.Credentialer.

+stateify savable

func NewSocket

func NewSocket(t *kernel.Task, skType linux.SockType, protocol Protocol) (*Socket, *syserr.Error)

NewSocket creates a new Socket.

func (*Socket) Accept

func (s *Socket) Accept(t *kernel.Task, peerRequested bool, flags int, blocking bool) (int32, linux.SockAddr, uint32, *syserr.Error)

Accept implements socket.Socket.Accept.

func (*Socket) Bind

func (s *Socket) Bind(t *kernel.Task, sockaddr []byte) *syserr.Error

Bind implements socket.Socket.Bind.

func (*Socket) Connect

func (s *Socket) Connect(t *kernel.Task, sockaddr []byte, blocking bool) *syserr.Error

Connect implements socket.Socket.Connect.

func (*Socket) ConnectedPasscred

func (s *Socket) ConnectedPasscred() bool

ConnectedPasscred implements transport.Credentialer.ConnectedPasscred.

func (*Socket) EventRegister

func (s *Socket) EventRegister(e *waiter.Entry) error

EventRegister implements waiter.Waitable.EventRegister.

func (*Socket) EventUnregister

func (s *Socket) EventUnregister(e *waiter.Entry)

EventUnregister implements waiter.Waitable.EventUnregister.

func (*Socket) GetPeerName

func (s *Socket) GetPeerName(t *kernel.Task) (linux.SockAddr, uint32, *syserr.Error)

GetPeerName implements socket.Socket.GetPeerName.

func (*Socket) GetSockName

func (s *Socket) GetSockName(t *kernel.Task) (linux.SockAddr, uint32, *syserr.Error)

GetSockName implements socket.Socket.GetSockName.

func (*Socket) GetSockOpt

func (s *Socket) GetSockOpt(t *kernel.Task, level int, name int, outPtr hostarch.Addr, outLen int) (marshal.Marshallable, *syserr.Error)

GetSockOpt implements socket.Socket.GetSockOpt.

func (*Socket) Ioctl

Ioctl implements fs.FileOperations.Ioctl.

func (*Socket) Listen

func (s *Socket) Listen(t *kernel.Task, backlog int) *syserr.Error

Listen implements socket.Socket.Listen.

func (*Socket) Passcred

func (s *Socket) Passcred() bool

Passcred implements transport.Credentialer.Passcred.

func (*Socket) Read

func (s *Socket) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequence, _ int64) (int64, error)

Read implements fs.FileOperations.Read.

func (*Socket) Readiness

func (s *Socket) Readiness(mask waiter.EventMask) waiter.EventMask

Readiness implements waiter.Waitable.Readiness.

func (*Socket) RecvMsg

func (s *Socket) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags int, haveDeadline bool, deadline ktime.Time, senderRequested bool, controlDataLen uint64) (int, int, linux.SockAddr, uint32, socket.ControlMessages, *syserr.Error)

RecvMsg implements socket.Socket.RecvMsg.

func (*Socket) Release

func (s *Socket) Release(ctx context.Context)

Release implements fs.FileOperations.Release.

func (*Socket) SendMsg

func (s *Socket) SendMsg(t *kernel.Task, src usermem.IOSequence, to []byte, flags int, haveDeadline bool, deadline ktime.Time, controlMessages socket.ControlMessages) (int, *syserr.Error)

SendMsg implements socket.Socket.SendMsg.

func (*Socket) SetSockOpt

func (s *Socket) SetSockOpt(t *kernel.Task, level int, name int, opt []byte) *syserr.Error

SetSockOpt implements socket.Socket.SetSockOpt.

func (*Socket) Shutdown

func (s *Socket) Shutdown(t *kernel.Task, how int) *syserr.Error

Shutdown implements socket.Socket.Shutdown.

func (*Socket) State

func (s *Socket) State() uint32

State implements socket.Socket.State.

func (*Socket) Type

func (s *Socket) Type() (family int, skType linux.SockType, protocol int)

Type implements socket.Socket.Type.

func (*Socket) Write

func (s *Socket) Write(ctx context.Context, _ *fs.File, src usermem.IOSequence, _ int64) (int64, error)

Write implements fs.FileOperations.Write.

type SocketVFS2

type SocketVFS2 struct {
	vfs.FileDescriptionDefaultImpl
	vfs.DentryMetadataFileDescriptionImpl
	vfs.LockFD
	// contains filtered or unexported fields
}

SocketVFS2 is the base VFS2 socket type for netlink sockets.

This implementation only supports userspace sending and receiving messages to/from the kernel.

SocketVFS2 implements socket.SocketVFS2 and transport.Credentialer.

+stateify savable

func NewVFS2

func NewVFS2(t *kernel.Task, skType linux.SockType, protocol Protocol) (*SocketVFS2, *syserr.Error)

NewVFS2 creates a new SocketVFS2.

func (*SocketVFS2) Accept

func (s *SocketVFS2) Accept(t *kernel.Task, peerRequested bool, flags int, blocking bool) (int32, linux.SockAddr, uint32, *syserr.Error)

Accept implements socket.Socket.Accept.

func (*SocketVFS2) Bind

func (s *SocketVFS2) Bind(t *kernel.Task, sockaddr []byte) *syserr.Error

Bind implements socket.Socket.Bind.

func (*SocketVFS2) Connect

func (s *SocketVFS2) Connect(t *kernel.Task, sockaddr []byte, blocking bool) *syserr.Error

Connect implements socket.Socket.Connect.

func (*SocketVFS2) ConnectedPasscred

func (s *SocketVFS2) ConnectedPasscred() bool

ConnectedPasscred implements transport.Credentialer.ConnectedPasscred.

func (*SocketVFS2) EventRegister

func (s *SocketVFS2) EventRegister(e *waiter.Entry) error

EventRegister implements waiter.Waitable.EventRegister.

func (*SocketVFS2) EventUnregister

func (s *SocketVFS2) EventUnregister(e *waiter.Entry)

EventUnregister implements waiter.Waitable.EventUnregister.

func (*SocketVFS2) GetPeerName

func (s *SocketVFS2) GetPeerName(t *kernel.Task) (linux.SockAddr, uint32, *syserr.Error)

GetPeerName implements socket.Socket.GetPeerName.

func (*SocketVFS2) GetSockName

func (s *SocketVFS2) GetSockName(t *kernel.Task) (linux.SockAddr, uint32, *syserr.Error)

GetSockName implements socket.Socket.GetSockName.

func (*SocketVFS2) GetSockOpt

func (s *SocketVFS2) GetSockOpt(t *kernel.Task, level int, name int, outPtr hostarch.Addr, outLen int) (marshal.Marshallable, *syserr.Error)

GetSockOpt implements socket.Socket.GetSockOpt.

func (*SocketVFS2) Ioctl

Ioctl implements vfs.FileDescriptionImpl.

func (*SocketVFS2) Listen

func (s *SocketVFS2) Listen(t *kernel.Task, backlog int) *syserr.Error

Listen implements socket.Socket.Listen.

func (*SocketVFS2) PRead

func (s *SocketVFS2) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error)

PRead implements vfs.FileDescriptionImpl.

func (*SocketVFS2) PWrite

func (s *SocketVFS2) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error)

PWrite implements vfs.FileDescriptionImpl.

func (*SocketVFS2) Passcred

func (s *SocketVFS2) Passcred() bool

Passcred implements transport.Credentialer.Passcred.

func (*SocketVFS2) Read

func (s *SocketVFS2) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error)

Read implements vfs.FileDescriptionImpl.

func (*SocketVFS2) Readiness

func (s *SocketVFS2) Readiness(mask waiter.EventMask) waiter.EventMask

Readiness implements waiter.Waitable.Readiness.

func (*SocketVFS2) RecvMsg

func (s *SocketVFS2) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags int, haveDeadline bool, deadline ktime.Time, senderRequested bool, controlDataLen uint64) (int, int, linux.SockAddr, uint32, socket.ControlMessages, *syserr.Error)

RecvMsg implements socket.Socket.RecvMsg.

func (*SocketVFS2) Release

func (s *SocketVFS2) Release(ctx context.Context)

Release implements vfs.FileDescriptionImpl.Release.

func (*SocketVFS2) SendMsg

func (s *SocketVFS2) SendMsg(t *kernel.Task, src usermem.IOSequence, to []byte, flags int, haveDeadline bool, deadline ktime.Time, controlMessages socket.ControlMessages) (int, *syserr.Error)

SendMsg implements socket.Socket.SendMsg.

func (*SocketVFS2) SetSockOpt

func (s *SocketVFS2) SetSockOpt(t *kernel.Task, level int, name int, opt []byte) *syserr.Error

SetSockOpt implements socket.Socket.SetSockOpt.

func (*SocketVFS2) Shutdown

func (s *SocketVFS2) Shutdown(t *kernel.Task, how int) *syserr.Error

Shutdown implements socket.Socket.Shutdown.

func (*SocketVFS2) State

func (s *SocketVFS2) State() uint32

State implements socket.Socket.State.

func (*SocketVFS2) Type

func (s *SocketVFS2) Type() (family int, skType linux.SockType, protocol int)

Type implements socket.Socket.Type.

func (*SocketVFS2) Write

func (s *SocketVFS2) Write(ctx context.Context, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error)

Write implements vfs.FileDescriptionImpl.

Directories

Path Synopsis
Package port provides port ID allocation for netlink sockets.
Package port provides port ID allocation for netlink sockets.
Package route provides a NETLINK_ROUTE socket protocol.
Package route provides a NETLINK_ROUTE socket protocol.
Package uevent provides a NETLINK_KOBJECT_UEVENT socket protocol.
Package uevent provides a NETLINK_KOBJECT_UEVENT socket protocol.

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