netcheck

type Client struct {
	// DERP is the DERP world to use.
	DERP *derpmap.World

	// DNSCache optionally specifies a DNSCache to use.
	// If nil, a DNS cache is not used.
	DNSCache *dnscache.Resolver

	// Logf optionally specifies where to log to.
	Logf logger.Logf

	// TimeNow, if non-nil, is used instead of time.Now.
	TimeNow func() time.Time

	GetSTUNConn4 func() STUNConn
	GetSTUNConn6 func() STUNConn
	// contains filtered or unexported fields
}

type Report struct {
	UDP                   bool                     // UDP works
	IPv6                  bool                     // IPv6 works
	MappingVariesByDestIP opt.Bool                 // for IPv4
	HairPinning           opt.Bool                 // for IPv4
	PreferredDERP         int                      // or 0 for unknown
	DERPLatency           map[string]time.Duration // keyed by STUN host:port

	GlobalV4 string // ip:port of global IPv4
	GlobalV6 string // [ip]:port of global IPv6 // TODO

}

type STUNConn interface {
	WriteTo([]byte, net.Addr) (int, error)
	ReadFrom([]byte) (int, net.Addr, error)
}