fastdialer

Documentation

Overview

fastdialer is a dialer package containing a dns/tls cache layer

Index

• Constants
• Variables
• func AsTLSConfig(ztlsConfig *ztls.Config) (*tls.Config, error)
• func AsZTLSConfig(tlsConfig *tls.Config) (*ztls.Config, error)
• func HandleResolverLine(raw string) (ip string)
• func IsTLS13(config interface{}) bool
• type CacheType
• type ContextOption
• type Dialer
  • func NewDialer(options Options) (*Dialer, error)
  • func (d *Dialer) Close()
  • func (d *Dialer) Dial(ctx context.Context, network, address string) (conn net.Conn, err error)
  • func (d *Dialer) DialTLS(ctx context.Context, network, address string) (conn net.Conn, err error)
  • func (d *Dialer) DialTLSWithConfig(ctx context.Context, network, address string, config *tls.Config) (conn net.Conn, err error)
  • func (d *Dialer) DialTLSWithConfigImpersonate(ctx context.Context, network, address string, config *tls.Config, ...) (conn net.Conn, err error)
  • func (d *Dialer) DialZTLS(ctx context.Context, network, address string) (conn net.Conn, err error)
  • func (d *Dialer) DialZTLSWithConfig(ctx context.Context, network, address string, config *ztls.Config) (conn net.Conn, err error)
  • func (d *Dialer) GetDNSData(hostname string) (*retryabledns.DNSData, error)
  • func (d *Dialer) GetDNSDataFromCache(hostname string) (*retryabledns.DNSData, error)
  • func (d *Dialer) GetDialedIP(hostname string) string
  • func (d *Dialer) GetTLSData(hostname string) (*cryptoutil.TLSData, error)
  • func (d *Dialer) GetTimeout() time.Duration
• type DiskDBType
• type Options
• type ResolverConfig

Constants

const (
	// DefaultMaxResolverEntries is the default maximum number of resolver
	// entries to read from the resolvers file.
	DefaultMaxResolverEntries = 4096

	// DefaultNdots is the default ndots value.
	DefaultNdots = 1
)

const ResolverFilePath = "/etc/resolv.conf"

ResolverFilePath in unix file os

Variables

var (
	MaxDNSCacheSize  int64
	MaxDNSItems      = 1024
	MaxDialCacheSize = 10000
)

option to disable ztls fallback in case of handshake error reads from env variable DISABLE_ZTLS_FALLBACK

var (
	CouldNotConnectError  = errkit.New("could not connect to any address found for host").SetKind(errkit.ErrKindNetworkPermanent)
	NoAddressFoundError   = errkit.New("no address found for host").SetKind(errkit.ErrKindNetworkPermanent)
	NoAddressAllowedError = errkit.New("denied address found for host").SetKind(errkit.ErrKindNetworkPermanent)
	NoPortSpecifiedError  = errkit.New("port was not specified").SetKind(errkit.ErrKindNetworkPermanent)
	MalformedIP6Error     = errkit.New("malformed IPv6 address").SetKind(errkit.ErrKindNetworkPermanent)
	ResolveHostError      = errkit.New("could not resolve host").SetKind(errkit.ErrKindNetworkPermanent)
	NoTLSHistoryError     = errkit.New("no tls data history available")
	NoTLSDataError        = errkit.New("no tls data found for the key")
	NoDNSDataError        = errkit.New("no data found")
	AsciiConversionError  = errkit.New("could not convert hostname to ASCII")
	ErrDialTimeout        = errkit.New("dial timeout").SetKind(errkit.ErrKindNetworkTemporary)
)

var DefaultOptions = Options{
	BaseResolvers:                   DefaultResolvers,
	MaxRetries:                      5,
	HostsFile:                       true,
	ResolversFile:                   true,
	CacheType:                       Memory,
	DialerTimeout:                   10 * time.Second,
	DialerKeepAlive:                 10 * time.Second,
	MaxTemporaryErrors:              30,
	MaxTemporaryToPermanentDuration: time.Minute,
}

DefaultOptions of the cache

var DefaultResolvers = []string{
	"1.1.1.1:53",
	"1.0.0.1:53",
	"8.8.8.8:53",
	"8.8.4.4:53",
}

DefaultResolvers trusted

var DefaultTLSConfig = &tls.Config{
	Renegotiation:      tls.RenegotiateOnceAsClient,
	InsecureSkipVerify: true,
	MinVersion:         tls.VersionTLS10,
	CipherSuites:       getUnsafeCipherSuites(),
}

DefaultTLSConfig is a default TLS configuration that is used by the fastdialer.

var DefaultZTLSConfig = &ztls.Config{
	InsecureSkipVerify: true,
	MinVersion:         ztls.VersionTLS10,
	CipherSuites:       getUnsafeCipherSuites(),
}

DefaultZTLSConfig is a default ZTLS configuration that is used by the fastdialer.

var MaxDialerTimeout = time.Minute

var (
	// MaxResolverEntries limits the number of resolver entries parsed from
	// resolver file.
	//
	// -1 means no limit.
	//
	// Deprecated: Use [DefaultMaxResolverEntries] instead. Adjust via [Options].
	MaxResolverEntries = 4096
)

var MinDialerTimeout = time.Second

Functions

func AsTLSConfig

func AsTLSConfig(ztlsConfig *ztls.Config) (*tls.Config, error)

func AsZTLSConfig

func AsZTLSConfig(tlsConfig *tls.Config) (*ztls.Config, error)

func HandleResolverLine

func HandleResolverLine(raw string) (ip string)

HandleLine a resolver file line

func IsTLS13

func IsTLS13(config interface{}) bool

Types

type CacheType

type CacheType uint8

const (
	Memory CacheType = iota
	Disk
	Hybrid
)

type ContextOption

type ContextOption string

const (
	// SniName to use in tls connection
	SniName ContextOption = "sni-name"
	IP      ContextOption = "ip"
)

type Dialer

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

Dialer structure containing data information

func NewDialer

func NewDialer(options Options) (*Dialer, error)

NewDialer instance

func (*Dialer) Close

func (d *Dialer) Close()

Close instance and cleanups

func (*Dialer) Dial

func (d *Dialer) Dial(ctx context.Context, network, address string) (conn net.Conn, err error)

Dial function compatible with net/http

func (*Dialer) DialTLS

func (d *Dialer) DialTLS(ctx context.Context, network, address string) (conn net.Conn, err error)

DialTLS with encrypted connection

Note that this configuration is included for compatibility with the Go version <1.22, and is not intended to be secure. It is recommended to use the DialTLSWithConfig or DialTLSWithConfigImpersonate methods instead.

func (*Dialer) DialTLSWithConfig

func (d *Dialer) DialTLSWithConfig(ctx context.Context, network, address string, config *tls.Config) (conn net.Conn, err error)

DialTLS with encrypted connection

func (*Dialer) DialTLSWithConfigImpersonate

func (d *Dialer) DialTLSWithConfigImpersonate(ctx context.Context, network, address string, config *tls.Config, impersonate impersonate.Strategy, identity *impersonate.Identity) (conn net.Conn, err error)

DialTLSWithConfigImpersonate dials tls with impersonation

func (*Dialer) DialZTLS

func (d *Dialer) DialZTLS(ctx context.Context, network, address string) (conn net.Conn, err error)

DialZTLS with encrypted connection using ztls

Note that this configuration is included for compatibility with the Go version <1.22, and is not intended to be secure. It is recommended to use the DialZTLSWithConfig method instead.

func (*Dialer) DialZTLSWithConfig

func (d *Dialer) DialZTLSWithConfig(ctx context.Context, network, address string, config *ztls.Config) (conn net.Conn, err error)

DialZTLSWithConfig dials ztls with config

func (*Dialer) GetDNSData

func (d *Dialer) GetDNSData(hostname string) (*retryabledns.DNSData, error)

GetDNSData for the given hostname

func (*Dialer) GetDNSDataFromCache

func (d *Dialer) GetDNSDataFromCache(hostname string) (*retryabledns.DNSData, error)

GetDNSDataFromCache cached by the resolver

func (*Dialer) GetDialedIP

func (d *Dialer) GetDialedIP(hostname string) string

GetDialedIP returns the ip dialed by the HTTP client

func (*Dialer) GetTLSData

func (d *Dialer) GetTLSData(hostname string) (*cryptoutil.TLSData, error)

GetTLSData returns the tls data for a hostname

func (*Dialer) GetTimeout

func (d *Dialer) GetTimeout() time.Duration

GetTimeout returns the maximum timeout allowed for dialer

type DiskDBType

type DiskDBType uint8

const (
	LevelDB DiskDBType = iota
	Pogreb
)

type Options

type Options struct {
	BaseResolvers       []string
	MaxRetries          int
	HostsFile           bool
	ResolversFile       bool
	EnableFallback      bool
	Allow               []string
	Deny                []string
	AllowSchemeList     []string
	DenySchemeList      []string
	AllowPortList       []int
	DenyPortList        []int
	CacheType           CacheType
	CacheMemoryMaxItems int // used by Memory cache type
	DiskDbType          DiskDBType
	WithDialerHistory   bool
	WithCleanup         bool
	WithTLSData         bool
	DialerTimeout       time.Duration
	DialerKeepAlive     time.Duration
	Dialer              *net.Dialer
	ProxyDialer         *proxy.Dialer
	WithZTLS            bool
	SNIName             string
	OnBeforeDial        func(hostname, IP, port string)
	// OnValidateTarget is called after network policy validation and before dialing.
	// If it returns an error, the target is considered invalid.
	OnValidateTarget         func(hostname, IP, port string) error
	OnInvalidTarget          func(hostname, IP, port string)
	OnDialCallback           func(hostname, IP string)
	DisableZtlsFallback      bool
	WithNetworkPolicyOptions *networkpolicy.Options
	// optional network policy override for sharing
	NetworkPolicy *networkpolicy.NetworkPolicy
	// optional logger to log errors(like hostfile init error)
	Logger *log.Logger
	// optional max temporary errors to mark as permanent
	MaxTemporaryErrors              int
	MaxTemporaryToPermanentDuration time.Duration

	// ConnectionCacheExpiry is the duration after which a cached connection
	// expires.
	//
	// Default is [DefaultConnExpiry].
	ConnectionCacheExpiry time.Duration

	// MaxResolverEntries limits the number of resolvers read from the resolvers
	// file.
	//
	// Default is [DefaultMaxResolverEntries].
	// Use -1 for unlimited entries.
	MaxResolverEntries int

	// Ndots enforces the resolv.conf(5) ndots: threshold for treating a name
	// as absolute before search domains are appended (see
	// https://man7.org/linux/man-pages/man5/resolv.conf.5.html).
	//
	// Default is [DefaultNdots].
	Ndots int
}

type ResolverConfig

type ResolverConfig struct {
	// Resolvers are the list of nameservers.
	Resolvers []string

	// SearchDomains are the search domains.
	SearchDomains []string

	// Ndots enforces the resolv.conf(5) ndots: threshold for treating a name
	// as absolute before search domains are appended (see
	// https://man7.org/linux/man-pages/man5/resolv.conf.5.html).
	Ndots int
}

ResolverConfig captures nameservers plus search-domain semantics from resolv.conf(5).