recursive

Documentation

Index

• Constants
• Variables
• func AddrFromRR(rr dns.RR) netip.Addr
• func DnsTypeToString(qtype uint16) string
• func MinTTL(msg *dns.Msg) int
• type Cache
  • func NewCache() *Cache
  • func (cache *Cache) Clean()
  • func (cache *Cache) Clear()
  • func (cache *Cache) Get(nsaddr netip.Addr, qname string, qtype uint16) *dns.Msg
  • func (cache *Cache) HitRatio() float64
  • func (cache *Cache) Set(nsaddr netip.Addr, msg *dns.Msg)
  • func (cache *Cache) Size() (n int)
• type Cacher
• type Resolver
  • func New() *Resolver
  • func NewWithOptions(roots4, roots6 []netip.Addr, cache Cacher) *Resolver
  • func (r *Resolver) QueryCount() uint64
  • func (r *Resolver) Resolve(qname string, qtype uint16) (msg *dns.Msg, srv netip.Addr, err error)
  • func (r *Resolver) ResolveWithOptions(ctx context.Context, dialer proxy.ContextDialer, cache Cacher, logw io.Writer, ...) (*dns.Msg, netip.Addr, error)

Constants

const DefaultMaxTTL = 3600

const DefaultMinTTL = 10

Variables

var (
	// ErrMaxDepth is returned when recursive resolving exceeds the allowed limit.
	ErrMaxDepth = fmt.Errorf("recursion depth exceeded %d", maxDepth)
	// ErrNoResponse is returned when no authoritative server could be successfully queried.
	// Consider it equivalent to SERVFAIL.
	ErrNoResponse = errors.New("no authoritative response")
	DefaultCache  = NewCache()
)

var Roots4 = []netip.Addr{
	netip.AddrFrom4([4]byte([]byte{0xc0, 0x5, 0x5, 0xf1})),
	netip.AddrFrom4([4]byte([]byte{0xc0, 0x21, 0x4, 0xc})),
	netip.AddrFrom4([4]byte([]byte{0xc0, 0x24, 0x94, 0x11})),
	netip.AddrFrom4([4]byte([]byte{0xc0, 0x3a, 0x80, 0x1e})),
	netip.AddrFrom4([4]byte([]byte{0xc0, 0x70, 0x24, 0x4})),
	netip.AddrFrom4([4]byte([]byte{0xc0, 0xcb, 0xe6, 0xa})),
	netip.AddrFrom4([4]byte([]byte{0xc1, 0x0, 0xe, 0x81})),
	netip.AddrFrom4([4]byte([]byte{0xc6, 0x29, 0x0, 0x4})),
	netip.AddrFrom4([4]byte([]byte{0xc6, 0x61, 0xbe, 0x35})),
	netip.AddrFrom4([4]byte([]byte{0xc7, 0x7, 0x53, 0x2a})),
	netip.AddrFrom4([4]byte([]byte{0xc7, 0x7, 0x5b, 0xd})),
	netip.AddrFrom4([4]byte([]byte{0xc7, 0x9, 0xe, 0xc9})),
	netip.AddrFrom4([4]byte([]byte{0xca, 0xc, 0x1b, 0x21})),
}

var Roots6 = []netip.Addr{
	netip.AddrFrom16([16]byte([]byte{0x20, 0x1, 0x5, 0x0, 0x0, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x53})),
	netip.AddrFrom16([16]byte([]byte{0x20, 0x1, 0x5, 0x0, 0x0, 0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xc})),
	netip.AddrFrom16([16]byte([]byte{0x20, 0x1, 0x5, 0x0, 0x0, 0x12, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xd, 0xd})),
	netip.AddrFrom16([16]byte([]byte{0x20, 0x1, 0x5, 0x0, 0x0, 0x2d, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xd})),
	netip.AddrFrom16([16]byte([]byte{0x20, 0x1, 0x5, 0x0, 0x0, 0x2f, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xf})),
	netip.AddrFrom16([16]byte([]byte{0x20, 0x1, 0x5, 0x0, 0x0, 0x9f, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x42})),
	netip.AddrFrom16([16]byte([]byte{0x20, 0x1, 0x5, 0x0, 0x0, 0xa8, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xe})),
	netip.AddrFrom16([16]byte([]byte{0x20, 0x1, 0x5, 0x0, 0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0xb})),
	netip.AddrFrom16([16]byte([]byte{0x20, 0x1, 0x5, 0x3, 0xc, 0x27, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x2, 0x0, 0x30})),
	netip.AddrFrom16([16]byte([]byte{0x20, 0x1, 0x5, 0x3, 0xba, 0x3e, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x2, 0x0, 0x30})),
	netip.AddrFrom16([16]byte([]byte{0x20, 0x1, 0x7, 0xfd, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1})),
	netip.AddrFrom16([16]byte([]byte{0x20, 0x1, 0x7, 0xfe, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x53})),
	netip.AddrFrom16([16]byte([]byte{0x20, 0x1, 0xd, 0xc3, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x35})),
}

Functions

func AddrFromRR

func AddrFromRR(rr dns.RR) netip.Addr

func DnsTypeToString

func DnsTypeToString(qtype uint16) string

func MinTTL

func MinTTL(msg *dns.Msg) int

MinTTL returns the lowest resource record TTL in the message, or -1 if there are no records.

Types

type Cache

type Cache struct {
	MinTTL int // always cache items for at least this long
	MaxTTL int // never cache items for longer than this
	// contains filtered or unexported fields
}

func NewCache

func NewCache() *Cache

func (*Cache) Clean

func (cache *Cache) Clean()

func (*Cache) Clear

func (cache *Cache) Clear()

func (*Cache) Get

func (cache *Cache) Get(nsaddr netip.Addr, qname string, qtype uint16) *dns.Msg

func (*Cache) HitRatio

func (cache *Cache) HitRatio() float64

HitRatio returns the hit ratio as a percentage.

func (*Cache) Set

func (cache *Cache) Set(nsaddr netip.Addr, msg *dns.Msg)

func (*Cache) Size

func (cache *Cache) Size() (n int)

Size returns the number of entries in the cache.

type Cacher

type Cacher interface {
	Get(nsaddr netip.Addr, qname string, qtype uint16) *dns.Msg
	Set(nsaddr netip.Addr, msg *dns.Msg)
}

type Resolver

type Resolver struct {
	Cache Cacher // Cacher to use by default
	// contains filtered or unexported fields
}

func New

func New() *Resolver

func NewWithOptions

func NewWithOptions(roots4, roots6 []netip.Addr, cache Cacher) *Resolver

func (*Resolver) QueryCount

func (r *Resolver) QueryCount() uint64

QueryCount returns the number of queries sent.

func (*Resolver) Resolve

func (r *Resolver) Resolve(qname string, qtype uint16) (msg *dns.Msg, srv netip.Addr, err error)

Resolve will perform a recursive DNS resolution for the provided name and record type.

func (*Resolver) ResolveWithOptions

func (r *Resolver) ResolveWithOptions(ctx context.Context, dialer proxy.ContextDialer, cache Cacher, logw io.Writer, qname string, qtype uint16) (*dns.Msg, netip.Addr, error)

ResolveWithOptions will perform a recursive DNS resolution for the provided name and record type, using the given dialer, and if logw is non-nil, write a log of events.