corrige detecção de endereços

internal/config/config.go

@@ -5,16 +5,30 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"strings"
 
 	"github.com/BurntSushi/toml"
 )
 
 const DefaultIntervalMinutes = 5
 
+// RecordType identifies which DNS record family an entry updates. Hurricane
+// Electric's dynamic DNS API cannot infer this from the submitted address
+// alone, so it must be configured explicitly per entry.
+type RecordType string
+
+const (
+	RecordTypeA    RecordType = "A"
+	RecordTypeAAAA RecordType = "AAAA"
+)
+
 // Entry describes a single Hurricane Electric dynamic DNS hostname to keep updated.
 type Entry struct {
 	Hostname string `toml:"hostname"`
 	Token    string `toml:"token"`
+	// RecordType selects whether this entry updates the A (IPv4) or AAAA
+	// (IPv6) record. Defaults to A when omitted.
+	RecordType RecordType `toml:"record_type"`
 }
 
 // Config is the top-level he-dydns configuration.
@@ -46,13 +60,25 @@ func Load(path string) (*Config, error) {
 	if len(cfg.Entries) == 0 {
 		return nil, fmt.Errorf("config %s: no entries defined", path)
 	}
-	for i, e := range cfg.Entries {
+	for i := range cfg.Entries {
+		e := &cfg.Entries[i]
 		if e.Hostname == "" {
 			return nil, fmt.Errorf("config %s: entries[%d] missing hostname", path, i)
 		}
 		if e.Token == "" {
 			return nil, fmt.Errorf("config %s: entries[%d] missing token", path, i)
 		}
+
+		switch RecordType(strings.ToUpper(string(e.RecordType))) {
+		case "":
+			e.RecordType = RecordTypeA
+		case RecordTypeA:
+			e.RecordType = RecordTypeA
+		case RecordTypeAAAA:
+			e.RecordType = RecordTypeAAAA
+		default:
+			return nil, fmt.Errorf("config %s: entries[%d] invalid record_type %q (must be \"A\" or \"AAAA\")", path, i, e.RecordType)
+		}
 	}
 
 	if cfg.IntervalMinutes <= 0 {

internal/network/network.go

@@ -2,6 +2,7 @@
 package network
 
 import (
+	"context"
 	"fmt"
 	"io"
 	"net"
@@ -83,14 +84,21 @@ func isUsable(ip net.IP) bool {
 
 func fromPublicServices() Addresses {
 	return Addresses{
-		IPv4: queryFirst(PublicIPv4Services, false),
-		IPv6: queryFirst(PublicIPv6Services, true),
+		IPv4: queryFirst(PublicIPv4Services, "tcp4", false),
+		IPv6: queryFirst(PublicIPv6Services, "tcp6", true),
 	}
 }
 
-func queryFirst(services []string, wantIPv6 bool) net.IP {
+// queryFirst tries each service in order over a connection forced to the
+// given network ("tcp4" or "tcp6"). Forcing the dial family avoids relying
+// on the target hostname having only an A or only an AAAA record: some of
+// these services answer on both families, and letting the OS pick (e.g. via
+// Happy Eyeballs) could silently return the wrong address family. The
+// resulting address family is still double-checked as a second safeguard.
+func queryFirst(services []string, network string, wantIPv6 bool) net.IP {
+	client := httpClientForNetwork(network)
 	for _, url := range services {
-		ip, err := queryOne(url)
+		ip, err := queryOne(client, url)
 		if err != nil {
 			continue
 		}
@@ -103,8 +111,19 @@ func queryFirst(services []string, wantIPv6 bool) net.IP {
 	return nil
 }
 
-func queryOne(url string) (net.IP, error) {
-	client := http.Client{Timeout: httpTimeout}
+func httpClientForNetwork(network string) *http.Client {
+	dialer := net.Dialer{Timeout: httpTimeout}
+	return &http.Client{
+		Timeout: httpTimeout,
+		Transport: &http.Transport{
+			DialContext: func(ctx context.Context, _, addr string) (net.Conn, error) {
+				return dialer.DialContext(ctx, network, addr)
+			},
+		},
+	}
+}
+
+func queryOne(client *http.Client, url string) (net.IP, error) {
 	resp, err := client.Get(url)
 	if err != nil {
 		return nil, err

internal/updater/updater.go

@@ -4,6 +4,7 @@ package updater
 import (
 	"fmt"
 	"log"
+	"net"
 
 	"git.aehoo.net/alphard/he-dydns/internal/config"
 	"git.aehoo.net/alphard/he-dydns/internal/hedns"
@@ -34,21 +35,24 @@ func Run(cfg *config.Config) error {
 
 	var failures int
 	for _, entry := range cfg.Entries {
-		if addrs.IPv4 != nil {
-			if err := hedns.Update(entry.Hostname, entry.Token, addrs.IPv4); err != nil {
-				log.Printf("error: %v", err)
-				failures++
-			} else {
-				log.Printf("updated %s -> %s", entry.Hostname, addrs.IPv4)
-			}
+		var ip net.IP
+		switch entry.RecordType {
+		case config.RecordTypeAAAA:
+			ip = addrs.IPv6
+		default:
+			ip = addrs.IPv4
 		}
-		if addrs.IPv6 != nil {
-			if err := hedns.Update(entry.Hostname, entry.Token, addrs.IPv6); err != nil {
-				log.Printf("error: %v", err)
-				failures++
-			} else {
-				log.Printf("updated %s -> %s", entry.Hostname, addrs.IPv6)
-			}
+
+		if ip == nil {
+			log.Printf("no %s address available for %s; skipping", entry.RecordType, entry.Hostname)
+			continue
+		}
+
+		if err := hedns.Update(entry.Hostname, entry.Token, ip); err != nil {
+			log.Printf("error: %v", err)
+			failures++
+		} else {
+			log.Printf("updated %s (%s) -> %s", entry.Hostname, entry.RecordType, ip)
 		}
 	}