middleproxy

type DialParams ¶

type DialParams struct {
	DC         int
	ClientAddr *net.TCPAddr
	PublicIPv4 net.IP
	PublicIPv6 net.IP
	// PaddedIntermediate says the client's transport is 0xdddddddd, the only
	// one whose frames carry 0-15 bytes of trailing padding. It drives RPC_F_PAD
	// and the alignment trim, both of which are a lie for plain intermediate.
	PaddedIntermediate bool
	AdvertisedPort     int
	AdTag              [adTagLength]byte
}

DialParams carries the addressing the proxy contributes to a middle-proxy dial. ClientAddr is the real client's address (put in RPC_PROXY_REQ). PublicIPv4 and PublicIPv6 optionally override the address the middle proxy sees as our source (needed on multi-homed hosts); the family matching the dialed socket is used. AdvertisedPort is the port reported as ours in RPC_PROXY_REQ.

type Dialer ¶

type Dialer interface {
	Dial(network, address string) (essentials.Conn, error)
}

Dialer is the subset of mtglib.Network the manager needs to reach a middle proxy. It is declared here to keep this internal package free of an import cycle back to mtglib.

type Logger ¶

type Logger interface {
	Info(string)
	Warning(string)
}

Logger is the minimal logging surface used by the background refresh loop. mtglib.Logger satisfies it.

type Manager ¶

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

Manager fetches and caches Telegram's proxy secret and middle-proxy address lists, and dials RPC proxy streams that carry an ad_tag. It fetches lazily on first use (so a proxy without advertising never touches the network) and then refreshes hourly. It is safe for concurrent use.

Exactly one fetch is ever in a client's path: the first. Every later one runs in the background, and a dial that arrives while the manager is not ready is told so at once and takes the direct route. This is the whole design: a fetch is three sequential HTTP requests of up to fetchTimeout each against a host the network may well be blocking, and an earlier version queued every ad-tagged dial behind it, so a proxy whose ad-tag was configured on a network that could not reach core.telegram.org held every client for up to ninety seconds, one after another, before letting each one through direct.

func NewManager(ctx context.Context, httpClient *http.Client, logger Logger, preferIP string) *Manager

func (m *Manager) DialProxyStream(dialer Dialer, params DialParams) (essentials.Conn, net.IP, error)

func (m *Manager) Ready() bool

func (m *Manager) Warm()