utils

Documentation

Index

• Constants
• func GenerateCertificate(dnsName string) (cert tls.Certificate, err error)
• func GetIPFromAddr(addr net.Addr) (ip net.IP)
• func GetMsgBuf(size int) []byte
• func GetMsgBufFor(m *dns.Msg) ([]byte, error)
• func GetMsgKey(m *dns.Msg) (string, error)
• func GetTimer(t time.Duration) *time.Timer
• func LoadCertPool(certs []string) (*x509.CertPool, error)
• func ParseAddr(addr string) (protocol, host string)
• func ReadMsgFromTCP(c io.Reader) (m *dns.Msg, n int, err error)
• func ReadMsgFromUDP(c io.Reader, bufSize int) (m *dns.Msg, n int, err error)
• func ReadUDPMsgFrom(c net.PacketConn, bufSize int) (m *dns.Msg, from net.Addr, n int, err error)
• func ReleaseMsgBuf(buf []byte)
• func ReleaseTimer(timer *time.Timer)
• func RemoveComment(s, symbol string) string
• func ResetAndDrainTimer(timer *time.Timer, d time.Duration)
• func SplitLine(s string) []string
• func TryAddPort(host string, port uint16) string
• func WriteMsgToTCP(c io.Writer, m *dns.Msg) (n int, err error)
• func WriteMsgToUDP(c io.Writer, m *dns.Msg) (n int, err error)
• func WriteRawMsgToTCP(c io.Writer, b []byte) (n int, err error)
• func WriteRawMsgToUDP(c io.Writer, b []byte) (n int, err error)
• func WriteUDPMsgTo(m *dns.Msg, c net.PacketConn, to net.Addr) (n int, err error)
• type Allocator
  • func NewAllocator() *Allocator
  • func (alloc *Allocator) Get(size int) []byte
  • func (alloc *Allocator) Put(buf []byte)
• type ExchangeSingleFlightGroup
  • func (g *ExchangeSingleFlightGroup) Exchange(ctx context.Context, q *dns.Msg, exchange exchangeFunc) (r *dns.Msg, err error)
• type LoadOnceCache
  • func NewCache() *LoadOnceCache
  • func (c *LoadOnceCache) Load(key string) (interface{}, bool)
  • func (c *LoadOnceCache) LoadFromCacheOrRawDisk(file string) (interface{}, []byte, error)
  • func (c *LoadOnceCache) Put(key string, data interface{}, ttl time.Duration)
  • func (c *LoadOnceCache) Remove(key string)
• type NetAddr
  • func NewNetAddr(str string, network string) *NetAddr
  • func (n *NetAddr) Network() string
  • func (n *NetAddr) String() string

Constants

const (
	IPv4UdpMaxPayload = 1472 // MTU 1500 - 20 IPv4 header - 8 udp header
	IPv6UdpMaxPayload = 1452 // MTU 1500 - 40 IPv6 header - 8 udp header
)

Functions

func GenerateCertificate

func GenerateCertificate(dnsName string) (cert tls.Certificate, err error)

GenerateCertificate generates a ecdsa certificate with given dnsName. This should only use in test.

func GetIPFromAddr

func GetIPFromAddr(addr net.Addr) (ip net.IP)

GetIPFromAddr returns net.IP from net.Addr. Will return nil if no ip address can be parsed.

func GetMsgBuf

func GetMsgBuf(size int) []byte

func GetMsgBufFor

func GetMsgBufFor(m *dns.Msg) ([]byte, error)

func GetMsgKey

func GetMsgKey(m *dns.Msg) (string, error)

GetMsgKey unpacks m and set its id to 0.

func GetTimer

func GetTimer(t time.Duration) *time.Timer

func LoadCertPool

func LoadCertPool(certs []string) (*x509.CertPool, error)

LoadCertPool reads and loads certificates in certs.

func ParseAddr

func ParseAddr(addr string) (protocol, host string)

ParseAddr splits addr to protocol and host.

func ReadMsgFromTCP

func ReadMsgFromTCP(c io.Reader) (m *dns.Msg, n int, err error)

ReadMsgFromTCP reads msg from a tcp connection. n represents how many bytes are read from c.

func ReadMsgFromUDP

func ReadMsgFromUDP(c io.Reader, bufSize int) (m *dns.Msg, n int, err error)

func ReadUDPMsgFrom

func ReadUDPMsgFrom(c net.PacketConn, bufSize int) (m *dns.Msg, from net.Addr, n int, err error)

func ReleaseMsgBuf

func ReleaseMsgBuf(buf []byte)

func ReleaseTimer

func ReleaseTimer(timer *time.Timer)

func RemoveComment

func RemoveComment(s, symbol string) string

RemoveComment removes comment after "symbol".

func ResetAndDrainTimer

func ResetAndDrainTimer(timer *time.Timer, d time.Duration)

func SplitLine

func SplitLine(s string) []string

SplitLine extracts words from s.

func TryAddPort

func TryAddPort(host string, port uint16) string

TryAddPort add port to host if host does not has an port suffix.

func WriteMsgToTCP

func WriteMsgToTCP(c io.Writer, m *dns.Msg) (n int, err error)

WriteMsgToTCP writes m to c. n represents how many bytes are wrote to c. This includes 2 bytes tcp header.

func WriteMsgToUDP

func WriteMsgToUDP(c io.Writer, m *dns.Msg) (n int, err error)

func WriteRawMsgToTCP

func WriteRawMsgToTCP(c io.Writer, b []byte) (n int, err error)

WriteRawMsgToTCP writes b to c. n represents how many bytes are wrote to c. This includes 2 bytes tcp header.

func WriteRawMsgToUDP

func WriteRawMsgToUDP(c io.Writer, b []byte) (n int, err error)

func WriteUDPMsgTo

func WriteUDPMsgTo(m *dns.Msg, c net.PacketConn, to net.Addr) (n int, err error)

Types

type Allocator

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

func NewAllocator

func NewAllocator() *Allocator

NewAllocator initiates a []byte allocator for dns.Msg less than 65536 bytes, the waste(memory fragmentation) of space allocation is guaranteed to be no more than 50%.

func (*Allocator) Get

func (alloc *Allocator) Get(size int) []byte

Get a []byte from pool with most appropriate cap

func (*Allocator) Put

func (alloc *Allocator) Put(buf []byte)

Put returns a []byte to pool for future use, which the cap must be exactly 2^n

type ExchangeSingleFlightGroup

type ExchangeSingleFlightGroup struct {
	singleflight.Group
}

func (*ExchangeSingleFlightGroup) Exchange

func (g *ExchangeSingleFlightGroup) Exchange(ctx context.Context, q *dns.Msg, exchange exchangeFunc) (r *dns.Msg, err error)

type LoadOnceCache

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

func NewCache

func NewCache() *LoadOnceCache

func (*LoadOnceCache) Load

func (c *LoadOnceCache) Load(key string) (interface{}, bool)

func (*LoadOnceCache) LoadFromCacheOrRawDisk

func (c *LoadOnceCache) LoadFromCacheOrRawDisk(file string) (interface{}, []byte, error)

func (*LoadOnceCache) Put

func (c *LoadOnceCache) Put(key string, data interface{}, ttl time.Duration)

func (*LoadOnceCache) Remove

func (c *LoadOnceCache) Remove(key string)

type NetAddr

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

NetAddr implements net.Addr interface.

func NewNetAddr

func NewNetAddr(str string, network string) *NetAddr

func (*NetAddr) Network

func (n *NetAddr) Network() string

func (*NetAddr) String

func (n *NetAddr) String() string