Add client debug features

client/anonymize/anonymize.go

@@ -0,0 +1,212 @@
+package anonymize
+
+import (
+	"crypto/rand"
+	"fmt"
+	"math/big"
+	"net"
+	"net/netip"
+	"net/url"
+	"regexp"
+	"slices"
+	"strings"
+)
+
+type Anonymizer struct {
+	ipAnonymizer     map[netip.Addr]netip.Addr
+	domainAnonymizer map[string]string
+	currentAnonIPv4  netip.Addr
+	currentAnonIPv6  netip.Addr
+	startAnonIPv4    netip.Addr
+	startAnonIPv6    netip.Addr
+}
+
+func DefaultAddresses() (netip.Addr, netip.Addr) {
+	// 192.51.100.0, 100::
+	return netip.AddrFrom4([4]byte{198, 51, 100, 0}), netip.AddrFrom16([16]byte{0x01})
+}
+
+func NewAnonymizer(startIPv4, startIPv6 netip.Addr) *Anonymizer {
+	return &Anonymizer{
+		ipAnonymizer:     map[netip.Addr]netip.Addr{},
+		domainAnonymizer: map[string]string{},
+		currentAnonIPv4:  startIPv4,
+		currentAnonIPv6:  startIPv6,
+		startAnonIPv4:    startIPv4,
+		startAnonIPv6:    startIPv6,
+	}
+}
+
+func (a *Anonymizer) AnonymizeIP(ip netip.Addr) netip.Addr {
+	if ip.IsLoopback() ||
+		ip.IsLinkLocalUnicast() ||
+		ip.IsLinkLocalMulticast() ||
+		ip.IsInterfaceLocalMulticast() ||
+		ip.IsPrivate() ||
+		ip.IsUnspecified() ||
+		ip.IsMulticast() ||
+		isWellKnown(ip) ||
+		a.isInAnonymizedRange(ip) {
+
+		return ip
+	}
+
+	if _, ok := a.ipAnonymizer[ip]; !ok {
+		if ip.Is4() {
+			a.ipAnonymizer[ip] = a.currentAnonIPv4
+			a.currentAnonIPv4 = a.currentAnonIPv4.Next()
+		} else {
+			a.ipAnonymizer[ip] = a.currentAnonIPv6
+			a.currentAnonIPv6 = a.currentAnonIPv6.Next()
+		}
+	}
+	return a.ipAnonymizer[ip]
+}
+
+// isInAnonymizedRange checks if an IP is within the range of already assigned anonymized IPs
+func (a *Anonymizer) isInAnonymizedRange(ip netip.Addr) bool {
+	if ip.Is4() && ip.Compare(a.startAnonIPv4) >= 0 && ip.Compare(a.currentAnonIPv4) <= 0 {
+		return true
+	} else if !ip.Is4() && ip.Compare(a.startAnonIPv6) >= 0 && ip.Compare(a.currentAnonIPv6) <= 0 {
+		return true
+	}
+	return false
+}
+
+func (a *Anonymizer) AnonymizeIPString(ip string) string {
+	addr, err := netip.ParseAddr(ip)
+	if err != nil {
+		return ip
+	}
+
+	return a.AnonymizeIP(addr).String()
+}
+
+func (a *Anonymizer) AnonymizeDomain(domain string) string {
+	if strings.HasSuffix(domain, "netbird.io") ||
+		strings.HasSuffix(domain, "netbird.selfhosted") ||
+		strings.HasSuffix(domain, "netbird.cloud") ||
+		strings.HasSuffix(domain, "netbird.stage") ||
+		strings.HasSuffix(domain, ".domain") {
+		return domain
+	}
+
+	parts := strings.Split(domain, ".")
+	if len(parts) < 2 {
+		return domain
+	}
+
+	baseDomain := parts[len(parts)-2] + "." + parts[len(parts)-1]
+
+	anonymized, ok := a.domainAnonymizer[baseDomain]
+	if !ok {
+		anonymizedBase := "anon-" + generateRandomString(5) + ".domain"
+		a.domainAnonymizer[baseDomain] = anonymizedBase
+		anonymized = anonymizedBase
+	}
+
+	return strings.Replace(domain, baseDomain, anonymized, 1)
+}
+
+func (a *Anonymizer) AnonymizeURI(uri string) string {
+	u, err := url.Parse(uri)
+	if err != nil {
+		return uri
+	}
+
+	var anonymizedHost string
+	if u.Opaque != "" {
+		host, port, err := net.SplitHostPort(u.Opaque)
+		if err == nil {
+			anonymizedHost = fmt.Sprintf("%s:%s", a.AnonymizeDomain(host), port)
+		} else {
+			anonymizedHost = a.AnonymizeDomain(u.Opaque)
+		}
+		u.Opaque = anonymizedHost
+	} else if u.Host != "" {
+		host, port, err := net.SplitHostPort(u.Host)
+		if err == nil {
+			anonymizedHost = fmt.Sprintf("%s:%s", a.AnonymizeDomain(host), port)
+		} else {
+			anonymizedHost = a.AnonymizeDomain(u.Host)
+		}
+		u.Host = anonymizedHost
+	}
+	return u.String()
+}
+
+func (a *Anonymizer) AnonymizeString(str string) string {
+	ipv4Regex := regexp.MustCompile(`\b(?:[0-9]{1,3}\.){3}[0-9]{1,3}\b`)
+	ipv6Regex := regexp.MustCompile(`\b([0-9a-fA-F:]+:+[0-9a-fA-F]{0,4})(?:%[0-9a-zA-Z]+)?(?:\/[0-9]{1,3})?(?::[0-9]{1,5})?\b`)
+
+	str = ipv4Regex.ReplaceAllStringFunc(str, a.AnonymizeIPString)
+	str = ipv6Regex.ReplaceAllStringFunc(str, a.AnonymizeIPString)
+
+	for domain, anonDomain := range a.domainAnonymizer {
+		str = strings.ReplaceAll(str, domain, anonDomain)
+	}
+
+	str = a.AnonymizeSchemeURI(str)
+	str = a.AnonymizeDNSLogLine(str)
+
+	return str
+}
+
+// AnonymizeSchemeURI finds and anonymizes URIs with stun, stuns, turn, and turns schemes.
+func (a *Anonymizer) AnonymizeSchemeURI(text string) string {
+	re := regexp.MustCompile(`(?i)\b(stuns?:|turns?:|https?://)\S+\b`)
+
+	return re.ReplaceAllStringFunc(text, a.AnonymizeURI)
+}
+
+// AnonymizeDNSLogLine anonymizes domain names in DNS log entries by replacing them with a random string.
+func (a *Anonymizer) AnonymizeDNSLogLine(logEntry string) string {
+	domainPattern := `dns\.Question{Name:"([^"]+)",`
+	domainRegex := regexp.MustCompile(domainPattern)
+
+	return domainRegex.ReplaceAllStringFunc(logEntry, func(match string) string {
+		parts := strings.Split(match, `"`)
+		if len(parts) >= 2 {
+			domain := parts[1]
+			if strings.HasSuffix(domain, ".domain") {
+				return match
+			}
+			randomDomain := generateRandomString(10) + ".domain"
+			return strings.Replace(match, domain, randomDomain, 1)
+		}
+		return match
+	})
+}
+
+func isWellKnown(addr netip.Addr) bool {
+	wellKnown := []string{
+		"8.8.8.8", "8.8.4.4", // Google DNS IPv4
+		"2001:4860:4860::8888", "2001:4860:4860::8844", // Google DNS IPv6
+		"1.1.1.1", "1.0.0.1", // Cloudflare DNS IPv4
+		"2606:4700:4700::1111", "2606:4700:4700::1001", // Cloudflare DNS IPv6
+		"9.9.9.9", "149.112.112.112", // Quad9 DNS IPv4
+		"2620:fe::fe", "2620:fe::9", // Quad9 DNS IPv6
+	}
+
+	if slices.Contains(wellKnown, addr.String()) {
+		return true
+	}
+
+	cgnatRangeStart := netip.AddrFrom4([4]byte{100, 64, 0, 0})
+	cgnatRange := netip.PrefixFrom(cgnatRangeStart, 10)
+
+	return cgnatRange.Contains(addr)
+}
+
+func generateRandomString(length int) string {
+	const letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+	result := make([]byte, length)
+	for i := range result {
+		num, err := rand.Int(rand.Reader, big.NewInt(int64(len(letters))))
+		if err != nil {
+			continue
+		}
+		result[i] = letters[num.Int64()]
+	}
+	return string(result)
+}