Introduce explicit config

config/config.go

@@ -0,0 +1,129 @@
+package config
+
+import (
+	"encoding/hex"
+	"fmt"
+	"net"
+	"strconv"
+	"time"
+
+	"github.com/juju/errors"
+)
+
+type Config struct {
+	Debug    bool
+	Verbose  bool
+	BindIP   net.IP
+	BindPort uint16
+
+	PublicIPv4     net.IP
+	PublicIPv4Port uint16
+	PublicIPv6     net.IP
+	PublicIPv6Port uint16
+
+	StatsIP   net.IP
+	StatsPort uint16
+
+	TimeoutRead  time.Duration
+	TimeoutWrite time.Duration
+
+	Secret []byte
+}
+
+type URLs struct {
+	TG        string `json:"tg_url"`
+	TMe       string `json:"tme_url"`
+	TGQRCode  string `json:"tg_qrcode"`
+	TMeQRCode string `json:"tme_qrcode"`
+}
+
+type IPURLs struct {
+	IPv4 URLs `json:"ipv4"`
+	IPv6 URLs `json:"ipv6"`
+}
+
+func (c *Config) BindAddr() string {
+	return getAddr(c.BindIP, c.BindPort)
+}
+
+func (c *Config) IPv4Addr() string {
+	return getAddr(c.PublicIPv4, c.PublicIPv4Port)
+}
+
+func (c *Config) IPv6Addr() string {
+	return getAddr(c.PublicIPv6, c.PublicIPv6Port)
+}
+
+func (c *Config) StatAddr() string {
+	return getAddr(c.StatsIP, c.StatsPort)
+}
+
+func (c *Config) GetURLs() IPURLs {
+	return IPURLs{
+		IPv4: getURLs(c.PublicIPv4, c.PublicIPv4Port, c.Secret),
+		IPv6: getURLs(c.PublicIPv6, c.PublicIPv6Port, c.Secret),
+	}
+}
+
+func getAddr(host fmt.Stringer, port uint16) string {
+	return net.JoinHostPort(host.String(), strconv.Itoa(int(port)))
+}
+
+func NewConfig(debug, verbose bool,
+	bindIP net.IP, bindPort uint16,
+	publicIPv4 net.IP, PublicIPv4Port uint16,
+	publicIPv6 net.IP, publicIPv6Port uint16,
+	statsIP net.IP, statsPort uint16,
+	timeoutRead, timeoutWrite time.Duration,
+	secret string) (*Config, error) {
+	secretBytes, err := hex.DecodeString(secret)
+	if err != nil {
+		return nil, errors.Annotate(err, "Cannot create config")
+	}
+
+	if publicIPv4 == nil {
+		publicIPv4, err = getGlobalIPv4()
+		if err != nil {
+			return nil, errors.Errorf("Cannot get public IP")
+		}
+	}
+	if publicIPv4.To4() == nil {
+		return nil, errors.Errorf("IP %s is not IPv4", publicIPv4.String())
+	}
+	if PublicIPv4Port == 0 {
+		PublicIPv4Port = bindPort
+	}
+
+	if publicIPv6 == nil {
+		publicIPv6, err = getGlobalIPv6()
+		if err != nil {
+			publicIPv6 = publicIPv4
+		}
+	}
+	if publicIPv6.To16() == nil {
+		return nil, errors.Errorf("IP %s is not IPv6", publicIPv6.String())
+	}
+	if publicIPv6Port == 0 {
+		publicIPv6Port = bindPort
+	}
+
+	if statsIP == nil {
+		statsIP = publicIPv4
+	}
+
+	conf := &Config{
+		Debug:          debug,
+		Verbose:        verbose,
+		BindIP:         bindIP,
+		BindPort:       bindPort,
+		PublicIPv4:     publicIPv4,
+		PublicIPv4Port: PublicIPv4Port,
+		PublicIPv6:     publicIPv6,
+		PublicIPv6Port: publicIPv6Port,
+		TimeoutRead:    timeoutRead,
+		TimeoutWrite:   timeoutWrite,
+		Secret:         secretBytes,
+	}
+
+	return conf, nil
+}

config/global_ips.go

@@ -0,0 +1,38 @@
+package config
+
+import (
+	"io/ioutil"
+	"net"
+	"net/http"
+	"strings"
+
+	"github.com/juju/errors"
+)
+
+func getGlobalIPv4() (net.IP, error) {
+	return fetchIP("https://v4.ifconfig.co/ip")
+}
+
+func getGlobalIPv6() (net.IP, error) {
+	return fetchIP("https://v6.ifconfig.co/ip")
+}
+
+func fetchIP(url string) (net.IP, error) {
+	resp, err := http.Get(url)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	respData, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	ip := net.ParseIP(strings.TrimSpace(string(respData)))
+	if ip == nil {
+		return nil, errors.Errorf("ifconfig.co returns incorrect IP %s", resp)
+	}
+
+	return ip, nil
+}

config/urls.go

@@ -0,0 +1,59 @@
+package config
+
+import (
+	"encoding/hex"
+	"net"
+	"net/url"
+	"strconv"
+)
+
+func getURLs(addr net.IP, port uint16, secret []byte) (urls URLs) {
+	values := url.Values{}
+	values.Set("server", addr.String())
+	values.Set("port", strconv.Itoa(int(port)))
+	values.Set("secret", hex.EncodeToString(secret))
+
+	urls.TG = makeTGURL(values)
+	urls.TMe = makeTGURL(values)
+	urls.TGQRCode = makeQRCodeURL(urls.TG)
+	urls.TMeQRCode = makeQRCodeURL(urls.TG)
+
+	return
+}
+
+func makeTGURL(values url.Values) string {
+	tgURL := url.URL{
+		Scheme:   "tg",
+		Host:     "proxy",
+		RawQuery: values.Encode(),
+	}
+
+	return tgURL.String()
+}
+
+func makeTMeURL(values url.Values) string {
+	tMeURL := url.URL{
+		Scheme:   "https",
+		Host:     "t.me",
+		Path:     "proxy",
+		RawQuery: values.Encode(),
+	}
+
+	return tMeURL.String()
+}
+
+func makeQRCodeURL(data string) string {
+	QRURL := url.URL{
+		Scheme: "https",
+		Host:   "api.qrserver.com",
+		Path:   "v1/create-qr-code",
+	}
+
+	values := url.Values{}
+	values.Set("qzone", "4")
+	values.Set("format", "svg")
+	values.Set("data", data)
+	QRURL.RawQuery = values.Encode()
+
+	return QRURL.String()
+}