socks5

Documentation

Index

• Constants
• Variables
• func AddrFromReader(r io.Reader) ([]byte, error)
• func AddrPortFromSlice(b []byte) (netip.AddrPort, int, error)
• func AppendAddrFromAddrPort(b []byte, addrPort netip.AddrPort) []byte
• func AppendAddrFromConnAddr(b []byte, addr conn.Addr) []byte
• func AppendFromReader(b []byte, r io.Reader) ([]byte, error)
• func ClientConnect(rw io.ReadWriter, targetAddr conn.Addr) error
• func ClientRequest(rw io.ReadWriter, command byte, targetAddr conn.Addr) (addr conn.Addr, err error)
• func ClientUDPAssociate(rw io.ReadWriter, targetAddr conn.Addr) (conn.Addr, error)
• func ConnAddrFromReader(r io.Reader) (conn.Addr, error)
• func ConnAddrFromSlice(b []byte) (conn.Addr, int, error)
• func ConnAddrFromSliceWithDomainCache(b []byte, cachedDomain string) (conn.Addr, int, string, error)
• func LengthOfAddrFromAddrPort(addrPort netip.AddrPort) int
• func LengthOfAddrFromConnAddr(addr conn.Addr) int
• func ServerAccept(rw io.ReadWriter, enableTCP, enableUDP bool) (addr conn.Addr, err error)
• func ValidatePacketHeader(b []byte) error
• func WriteAddrFromAddrPort(b []byte, addrPort netip.AddrPort) (n int)
• func WriteAddrFromConnAddr(b []byte, addr conn.Addr) int
• func WritePacketHeader(b []byte)

Constants

const (
	AtypIPv4       = 1
	AtypDomainName = 3
	AtypIPv6       = 4
)

SOCKS address types as defined in RFC 1928 section 5.

const (
	// IPv4AddrLen is the size of an IPv4 SOCKS address in bytes.
	IPv4AddrLen = 1 + 4 + 2

	// IPv6AddrLen is the size of an IPv6 SOCKS address in bytes.
	IPv6AddrLen = 1 + 16 + 2

	// MaxAddrLen is the maximum size of a SOCKS address in bytes.
	MaxAddrLen = 1 + 1 + 255 + 2
)

const (
	MethodNoAuthenticationRequired = 0
	MethodGSSAPI                   = 1
	MethodUsernamePassword         = 2
	MethodNoAcceptable             = 0xFF
)

SOCKS5 authentication methods as defined in RFC 1928 section 3.

const (
	CmdConnect      = 1
	CmdBind         = 2
	CmdUDPAssociate = 3
)

SOCKS request commands as defined in RFC 1928 section 4.

const (
	Succeeded               = 0
	ErrGeneralFailure       = 1
	ErrConnectionNotAllowed = 2
	ErrNetworkUnreachable   = 3
	ErrHostUnreachable      = 4
	ErrConnectionRefused    = 5
	ErrTTLExpired           = 6
	ErrCommandNotSupported  = 7
	ErrAddressNotSupported  = 8
)

SOCKS errors as defined in RFC 1928 section 6.

const Version = 5

SOCKS version 5.

Variables

var (
	// IPv4UnspecifiedAddr represents 0.0.0.0:0.
	IPv4UnspecifiedAddr = [IPv4AddrLen]byte{AtypIPv4}

	// IPv6UnspecifiedAddr represents [::]:0.
	IPv6UnspecifiedAddr = [IPv6AddrLen]byte{AtypIPv6}
)

var (
	ErrUnsupportedSocksVersion         = errors.New("unsupported SOCKS version")
	ErrUnsupportedAuthenticationMethod = errors.New("unsupported authentication method")
	ErrUnsupportedCommand              = errors.New("unsupported command")
	ErrUDPAssociateDone                = errors.New("UDP ASSOCIATE done")
)

var ErrFragmentationNotSupported = errors.New("packet fragmentation is not supported")

Functions

func AddrFromReader

func AddrFromReader(r io.Reader) ([]byte, error)

AddrFromReader allocates and reads a SOCKS address from an io.Reader.

To avoid allocations, call AppendFromReader directly.

func AddrPortFromSlice

func AddrPortFromSlice(b []byte) (netip.AddrPort, int, error)

AddrPortFromSlice slices a SOCKS address from the beginning of b and returns the converted netip.AddrPort and the length of the SOCKS address.

func AppendAddrFromAddrPort

func AppendAddrFromAddrPort(b []byte, addrPort netip.AddrPort) []byte

AppendAddrFromAddrPort appends the netip.AddrPort to the buffer in the SOCKS address format.

If the address is an IPv4-mapped IPv6 address, it is converted to an IPv4 address.

func AppendAddrFromConnAddr

func AppendAddrFromConnAddr(b []byte, addr conn.Addr) []byte

AppendAddrFromConnAddr appends the address to the buffer in the SOCKS address format.

- Zero value address is treated as 0.0.0.0:0. - IPv4-mapped IPv6 address is converted to the equivalent IPv4 address.

func AppendFromReader

func AppendFromReader(b []byte, r io.Reader) ([]byte, error)

AppendFromReader reads just enough bytes from r to get a valid Addr and appends it to the buffer.

func ClientConnect

func ClientConnect(rw io.ReadWriter, targetAddr conn.Addr) error

ClientConnect writes a CONNECT request to targetAddr.

func ClientRequest

func ClientRequest(rw io.ReadWriter, command byte, targetAddr conn.Addr) (addr conn.Addr, err error)

ClientRequest writes a request to targetAddr and returns the bound address in reply.

func ClientUDPAssociate

func ClientUDPAssociate(rw io.ReadWriter, targetAddr conn.Addr) (conn.Addr, error)

ClientUDPAssociate writes a UDP ASSOCIATE request to targetAddr.

func ConnAddrFromReader

func ConnAddrFromReader(r io.Reader) (conn.Addr, error)

ConnAddrFromReader reads a SOCKS address from r and returns the converted conn.Addr.

func ConnAddrFromSlice

func ConnAddrFromSlice(b []byte) (conn.Addr, int, error)

ConnAddrFromSlice slices a SOCKS address from the beginning of b and returns the converted conn.Addr and the length of the SOCKS address.

func ConnAddrFromSliceWithDomainCache

func ConnAddrFromSliceWithDomainCache(b []byte, cachedDomain string) (conn.Addr, int, string, error)

ConnAddrFromSliceWithDomainCache is like ConnAddrFromSlice but uses a domain cache to minimize string allocations. The returned string is the updated domain cache.

func LengthOfAddrFromAddrPort

func LengthOfAddrFromAddrPort(addrPort netip.AddrPort) int

LengthOfAddrFromAddrPort returns the length of a SOCKS address converted from the netip.AddrPort.

func LengthOfAddrFromConnAddr

func LengthOfAddrFromConnAddr(addr conn.Addr) int

LengthOfAddrFromConnAddr returns the length of a SOCKS address converted from the conn.Addr.

- Zero value address is treated as 0.0.0.0:0. - IPv4-mapped IPv6 address is treated as the equivalent IPv4 address.

func ServerAccept

func ServerAccept(rw io.ReadWriter, enableTCP, enableUDP bool) (addr conn.Addr, err error)

ServerAccept processes an incoming request from rw.

enableTCP enables the CONNECT command. enableUDP enables the UDP ASSOCIATE command.

When UDP is enabled, rw must be a *net.TCPConn.

func ValidatePacketHeader

func ValidatePacketHeader(b []byte) error

ValidatePacketHeader validates RSV and FRAG at the beginning of b. The length of b must be at least 3 bytes.

func WriteAddrFromAddrPort

func WriteAddrFromAddrPort(b []byte, addrPort netip.AddrPort) (n int)

WriteAddrFromAddrPort writes the netip.AddrPort to the buffer in the SOCKS address format and returns the number of bytes written.

If the address is an IPv4-mapped IPv6 address, it is converted to an IPv4 address.

This function does not check whether b has sufficient space for the address. The caller may call LengthOfAddrFromAddrPort to get the required length.

func WriteAddrFromConnAddr

func WriteAddrFromConnAddr(b []byte, addr conn.Addr) int

WriteAddrFromConnAddr writes the address to the buffer in the SOCKS address format and returns the number of bytes written.

- Zero value address is treated as 0.0.0.0:0. - IPv4-mapped IPv6 address is converted to the equivalent IPv4 address.

This function does not check whether b has sufficient space for the address. The caller may call LengthOfAddrFromConnAddr to get the required length.

func WritePacketHeader

func WritePacketHeader(b []byte)

WritePacketHeader writes RSV and FRAG to the beginning of b. The length of b must be at least 3 bytes.