conn

Documentation

Index

• Constants
• Variables
• func AddrPortMappedEqual(l, r netip.AddrPort) bool
• func AddrPortToSockaddr(addrPort netip.AddrPort) (name *byte, namelen uint32)
• func AddrPortToSockaddrInet4(addrPort netip.AddrPort) unix.RawSockaddrInet4
• func AddrPortToSockaddrInet6(addrPort netip.AddrPort) unix.RawSockaddrInet6
• func AddrPortv4Mappedv6(addrPort netip.AddrPort) netip.AddrPort
• func DialTFOWithPayload(dialer *tfo.Dialer, address string, payload []byte) (n int, conn tfo.Conn, err error)
• func ListenUDP(network string, laddr string, pktinfo bool, fwmark int) (conn *net.UDPConn, err error, serr error)
• func NewDialer(dialerTFO bool, dialerFwmark int) (dialer tfo.Dialer)
• func NewListenConfig(listenerTFO bool, listenerFwmark int) (lc tfo.ListenConfig)
• func ParseFlagsForError(flags int) error
• func Recvmmsg(conn *net.UDPConn, msgvec []Mmsghdr) (n int, err error)
• func ResolveAddr(host string, preferIPv6 bool) (netip.Addr, error)
• func Sendmmsg(conn *net.UDPConn, msgvec []Mmsghdr) (n int, err error)
• func SockaddrToAddrPort(name *byte, namelen uint32) (netip.AddrPort, error)
• func UpdatePktinfoCache(pktinfoCache, cmsgs []byte, logger *zap.Logger) ([]byte, error)
• func WriteMsgvec(conn *net.UDPConn, msgvec []Mmsghdr) error
• type Addr
  • func AddrFromDomainPort(domain string, port uint16) (Addr, error)
  • func AddrFromHostPort(host string, port uint16) (Addr, error)
  • func AddrFromIPPort(addrPort netip.AddrPort) (addr Addr)
  • func MustAddrFromDomainPort(domain string, port uint16) Addr
  • func ParseAddr(s string) (Addr, error)
  • func (a Addr) AppendTo(b []byte) []byte
  • func (a Addr) Domain() string
  • func (a Addr) Host() string
  • func (a Addr) IP() netip.Addr
  • func (a Addr) IPPort() netip.AddrPort
  • func (a Addr) IsIP() bool
  • func (a Addr) MappedEquals(b Addr) bool
  • func (a Addr) MarshalText() ([]byte, error)
  • func (a Addr) Port() uint16
  • func (a Addr) ResolveIP(preferIPv6 bool) (netip.Addr, error)
  • func (a Addr) ResolveIPPort(preferIPv6 bool) (netip.AddrPort, error)
  • func (a Addr) String() string
  • func (a *Addr) UnmarshalText(text []byte) error
• type Mmsghdr

Constants

const SocketControlMessageBufferSize = 128

SocketControlMessageBufferSize specifies the buffer size for receiving socket control messages.

const UIO_MAXIOV = 1024

Source: include/uapi/linux/uio.h

Variables

var (
	ErrMessageTruncated        = errors.New("the packet is larger than the supplied buffer")
	ErrControlMessageTruncated = errors.New("the control message is larger than the supplied buffer")
)

Functions

func AddrPortMappedEqual

func AddrPortMappedEqual(l, r netip.AddrPort) bool

AddrPortMappedEqual returns whether the two addresses point to the same endpoint. An IPv4 address and an IPv4-mapped IPv6 address pointing to the same endpoint are considered equal. For example, 1.1.1.1:53 and [::ffff:1.1.1.1]:53 are considered equal.

func AddrPortToSockaddr

func AddrPortToSockaddr(addrPort netip.AddrPort) (name *byte, namelen uint32)

func AddrPortToSockaddrInet4

func AddrPortToSockaddrInet4(addrPort netip.AddrPort) unix.RawSockaddrInet4

func AddrPortToSockaddrInet6

func AddrPortToSockaddrInet6(addrPort netip.AddrPort) unix.RawSockaddrInet6

func AddrPortv4Mappedv6

func AddrPortv4Mappedv6(addrPort netip.AddrPort) netip.AddrPort

AddrPortv4Mappedv6 converts an IPv4 address to an IPv4-mapped IPv6 address. This function does nothing if addrPort is an IPv6 address.

func DialTFOWithPayload

func DialTFOWithPayload(dialer *tfo.Dialer, address string, payload []byte) (n int, conn tfo.Conn, err error)

DialTFOWithPayload uses a TFO dialer to dial the target and writes the initial payload. TFO is disabled if initial payload is empty.

func ListenUDP

func ListenUDP(network string, laddr string, pktinfo bool, fwmark int) (conn *net.UDPConn, err error, serr error)

ListenUDP wraps Go's net.ListenConfig.ListenPacket and sets socket options on supported platforms.

On Linux and Windows, IP_MTU_DISCOVER and IPV6_MTU_DISCOVER are set to IP_PMTUDISC_DO to disable IP fragmentation and encourage correct MTU settings. If pktinfo is true, IP_PKTINFO and IPV6_RECVPKTINFO are set to 1.

On Linux, SO_MARK is set to user-specified value.

On macOS and FreeBSD, IP_DONTFRAG, IPV6_DONTFRAG are set to 1 (Don't Fragment).

func NewDialer

func NewDialer(dialerTFO bool, dialerFwmark int) (dialer tfo.Dialer)

NewDialer returns a tfo.Dialer with the specified options applied.

func NewListenConfig

func NewListenConfig(listenerTFO bool, listenerFwmark int) (lc tfo.ListenConfig)

NewListenConfig returns a tfo.ListenConfig with the specified options applied.

func ParseFlagsForError

func ParseFlagsForError(flags int) error

ParseFlagsForError parses the message flags returned by the ReadMsgUDPAddrPort method and returns an error if MSG_TRUNC is set, indicating that the returned packet was truncated.

The check is skipped on Windows, because an error (WSAEMSGSIZE) is also returned when MSG_PARTIAL is set.

func Recvmmsg

func Recvmmsg(conn *net.UDPConn, msgvec []Mmsghdr) (n int, err error)

func ResolveAddr

func ResolveAddr(host string, preferIPv6 bool) (netip.Addr, error)

ResolveAddr resolves a domain name string into netip.Addr. String representations of IP addresses are not supported.

func Sendmmsg

func Sendmmsg(conn *net.UDPConn, msgvec []Mmsghdr) (n int, err error)

func SockaddrToAddrPort

func SockaddrToAddrPort(name *byte, namelen uint32) (netip.AddrPort, error)

func UpdatePktinfoCache

func UpdatePktinfoCache(pktinfoCache, cmsgs []byte, logger *zap.Logger) ([]byte, error)

On Linux and Windows, UpdatePktinfoCache filters out irrelevant socket control messages, saves IP_PKTINFO or IPV6_PKTINFO socket control messages to the pktinfo cache, and returns the updated pktinfo cache slice.

The returned pktinfo cache is unchanged if no relevant control messages are found.

On other platforms, this is a no-op.

func WriteMsgvec

func WriteMsgvec(conn *net.UDPConn, msgvec []Mmsghdr) error

WriteMsgvec repeatedly calls sendmmsg(2) until all messages in msgvec are written to the socket.

If the syscall returns an error, this function drops the message that caused the error, and continues sending. Only the last encountered error is returned.

Types

type Addr

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

Addr is the base address type used throughout the package.

An Addr is a port number combined with either an IP address or a domain name.

func AddrFromDomainPort

func AddrFromDomainPort(domain string, port uint16) (Addr, error)

AddrFromDomainPort returns an Addr from the provided domain name and port number.

func AddrFromHostPort

func AddrFromHostPort(host string, port uint16) (Addr, error)

AddrFromHostPort returns an Addr from the provided host string and port number. The host string may be a string representation of an IP address or a domain name.

func AddrFromIPPort

func AddrFromIPPort(addrPort netip.AddrPort) (addr Addr)

AddrFromIPPort returns an Addr from the provided netip.AddrPort.

func MustAddrFromDomainPort

func MustAddrFromDomainPort(domain string, port uint16) Addr

MustAddrFromDomainPort calls AddrFromDomainPort and panics on error.

func ParseAddr

func ParseAddr(s string) (Addr, error)

ParseAddr parses the provided string representation of an address and returns the parsed address or an error.

func (Addr) AppendTo

func (a Addr) AppendTo(b []byte) []byte

AppendTo appends the string representation of the address to the provided buffer.

func (Addr) Domain

func (a Addr) Domain() string

Domain returns the domain name. If the address is an IP address, the returned domain name is an empty string.

func (Addr) Host

func (a Addr) Host() string

Host returns the string representation of the IP address or the domain name.

func (Addr) IP

func (a Addr) IP() netip.Addr

IP returns the IP address. If the address is a domain name, the returned netip.Addr is a zero value.

func (Addr) IPPort

func (a Addr) IPPort() netip.AddrPort

IPPort returns a netip.AddrPort. If the address is a domain name, the returned netip.AddrPort contains a zero-value netip.Addr and the port number.

func (Addr) IsIP

func (a Addr) IsIP() bool

IsIP returns whether the address is an IP address. If false, the address is a domain name.

func (Addr) MappedEquals

func (a Addr) MappedEquals(b Addr) bool

MappedEquals returns whether the two addresses point to the same endpoint. An IPv4 address and an IPv4-mapped IPv6 address pointing to the same endpoint are considered equal. For example, 1.1.1.1:53 and [::ffff:1.1.1.1]:53 are considered equal.

func (Addr) MarshalText

func (a Addr) MarshalText() ([]byte, error)

MarshalText implements the encoding.TextMarshaler MarshalText method.

func (Addr) Port

func (a Addr) Port() uint16

Port returns the port number.

func (Addr) ResolveIP

func (a Addr) ResolveIP(preferIPv6 bool) (netip.Addr, error)

ResolveIP returns the IP address itself or the resolved IP address of the domain name.

func (Addr) ResolveIPPort

func (a Addr) ResolveIPPort(preferIPv6 bool) (netip.AddrPort, error)

ResolveIPPort returns the IP address itself or the resolved IP address of the domain name and the port number as a netip.AddrPort.

func (Addr) String

func (a Addr) String() string

String returns the string representation of the address.

func (*Addr) UnmarshalText

func (a *Addr) UnmarshalText(text []byte) error

UnmarshalText implements the encoding.TextUnmarshaler UnmarshalText method.

type Mmsghdr

type Mmsghdr struct {
	Msghdr unix.Msghdr
	Msglen uint32
}