initial commit

chain/resovle.go

@@ -0,0 +1,47 @@
+package chain
+
+import (
+	"context"
+	"fmt"
+	"net"
+
+	"github.com/go-gost/core/hosts"
+	"github.com/go-gost/core/logger"
+	"github.com/go-gost/core/resolver"
+)
+
+func resolve(ctx context.Context, network, addr string, r resolver.Resolver, hosts hosts.HostMapper, log logger.Logger) (string, error) {
+	if addr == "" {
+		return addr, nil
+	}
+
+	host, port, err := net.SplitHostPort(addr)
+	if err != nil {
+		return "", err
+	}
+	if host == "" {
+		return addr, nil
+	}
+
+	if hosts != nil {
+		if ips, _ := hosts.Lookup(network, host); len(ips) > 0 {
+			log.Debugf("hit host mapper: %s -> %s", host, ips)
+			return net.JoinHostPort(ips[0].String(), port), nil
+		}
+	}
+
+	if r != nil {
+		ips, err := r.Resolve(ctx, network, host)
+		if err != nil {
+			if err == resolver.ErrInvalid {
+				return addr, nil
+			}
+			log.Error(err)
+		}
+		if len(ips) == 0 {
+			return "", fmt.Errorf("resolver: domain %s does not exists", host)
+		}
+		return net.JoinHostPort(ips[0].String(), port), nil
+	}
+	return addr, nil
+}