dc

Documentation

Overview

Package dc manages Telegram datacenter connections.

Index

• Constants
• Variables
• func Init()
• func SetProbeLogger(logger func(format string, args ...any))
• func SetProbeSocks5(addr string) error
• type Addr
  • func DCAddresses(dc int) ([]Addr, bool)
  • func DCAddressesIPv4(dc int) ([]Addr, bool)
  • func DCAddressesIPv6(dc int) ([]Addr, bool)
  • func GetProbedAddresses(dc int) ([]Addr, bool)
  • func (a Addr) IP() net.IP
  • func (a Addr) IsIPv6() bool
• type DCProbeResult
• type IPPreference
• type ProbeResult

Constants

const DefaultDC = 2

DefaultDC is the fallback DC when unknown.

const ProbeTimeout = 5 * time.Second

ProbeTimeout is the timeout for each probe attempt.

Variables

var CDNDCs = map[int][]Addr{
	203: {
		{Network: "tcp4", Address: "91.105.192.100:443"},
	},
}

CDN/regional DC overrides for special DCs (200+).

var DefaultDCs = map[int][]Addr{
	1: {

		{Network: "tcp4", Address: "149.154.175.50:443"},

		{Network: "tcp4", Address: "149.154.175.58:443"},

		{Network: "tcp6", Address: "[2001:b28:f23d:f001::a]:443"},
	},
	2: {

		{Network: "tcp4", Address: "149.154.167.51:443"},
		{Network: "tcp4", Address: "95.161.76.100:443"},

		{Network: "tcp4", Address: "149.154.167.41:443"},

		{Network: "tcp6", Address: "[2001:67c:4e8:f002::a]:443"},
	},
	3: {

		{Network: "tcp4", Address: "149.154.175.100:443"},

		{Network: "tcp6", Address: "[2001:b28:f23d:f003::a]:443"},
	},
	4: {

		{Network: "tcp4", Address: "149.154.167.91:443"},

		{Network: "tcp4", Address: "149.154.167.92:443"},

		{Network: "tcp6", Address: "[2001:67c:4e8:f004::a]:443"},
	},
	5: {

		{Network: "tcp4", Address: "149.154.171.5:443"},

		{Network: "tcp4", Address: "91.108.56.156:443"},

		{Network: "tcp6", Address: "[2001:b28:f23f:f005::a]:443"},
	},
}

Default Telegram DC addresses. Merged from tdesktop source + live API for redundancy. tdesktop: https://github.com/telegramdesktop/tdesktop/blob/master/Telegram/SourceFiles/mtproto/mtproto_dc_options.cpp

Functions

func Init

func Init()

Init probes all DC addresses and sorts them by RTT. Should be called once at startup. Blocks until complete.

func SetProbeLogger

func SetProbeLogger(logger func(format string, args ...any))

SetProbeLogger sets the logger for probe output.

func SetProbeSocks5

func SetProbeSocks5(addr string) error

SetProbeSocks5 sets the SOCKS5 proxy for DC probing.

Types

type Addr

type Addr struct {
	Network string // "tcp4" or "tcp6"
	Address string // "host:port"
}

Addr represents a datacenter address.

func DCAddresses

func DCAddresses(dc int) ([]Addr, bool)

DCAddresses returns addresses for a given DC. Negative DC IDs are media-only variants; we use the absolute value for lookup. Returns (addresses, true) if DC is known, (fallback addresses, false) if unknown.

func DCAddressesIPv4

func DCAddressesIPv4(dc int) ([]Addr, bool)

DCAddressesIPv4 returns only IPv4 addresses for a DC.

func DCAddressesIPv6

func DCAddressesIPv6(dc int) ([]Addr, bool)

DCAddressesIPv6 returns only IPv6 addresses for a DC.

func GetProbedAddresses

func GetProbedAddresses(dc int) ([]Addr, bool)

GetProbedAddresses returns addresses sorted by RTT for a DC. Falls back to default addresses if probing hasn't been done.

func (Addr) IP

func (a Addr) IP() net.IP

IP returns the IP address without port.

func (Addr) IsIPv6

func (a Addr) IsIPv6() bool

IsIPv6 returns true if this is an IPv6 address.

type DCProbeResult

type DCProbeResult struct {
	DCID    int
	Results []ProbeResult
}

DCProbeResult holds all probe results for a single DC.

type IPPreference

type IPPreference int

IPPreference controls which IP version to prefer.

const (
	PreferIPv4 IPPreference = iota
	PreferIPv6
	OnlyIPv4
	OnlyIPv6
)

type ProbeResult

type ProbeResult struct {
	Addr    Addr
	RTT     time.Duration
	Success bool
	Error   string
}

ProbeResult holds the result of probing a single address.