feat: add plugin

tls/dial.go

@@ -0,0 +1,94 @@
+package tls
+
+import (
+	"context"
+	"crypto/tls"
+	"errors"
+	"net"
+
+	"github.com/fumiama/terasu"
+	"github.com/fumiama/terasu/dialer"
+)
+
+// ErrEmptyHostAddress is returned when DNS lookup for a host returns no addresses
+var ErrEmptyHostAddress = errors.New("empty host addr")
+
+// DialTLSContextWithConfigAndSystemResolver fills http2.Transport method with terasu and system DNS
+func DialTLSContextWithConfigAndSystemResolver(ctx context.Context, network, addr string, cfg *tls.Config) (net.Conn, error) {
+	return DialTLSContextCL(ctx, network, addr, cfg, nil)
+}
+
+// DialTLSContextCL fills http2.Transport method with terasu
+func DialTLSContextCL(
+	ctx context.Context, network, addr string,
+	cfg *tls.Config, lookup func(ctx context.Context, host string,
+	) (addrs []string, err error)) (net.Conn, error) {
+	host, port, err := net.SplitHostPort(addr)
+	if err != nil {
+		return nil, err
+	}
+	var addrs []string
+	if lookup != nil {
+		addrs, err = lookup(ctx, host)
+	} else {
+		addrs, err = net.DefaultResolver.LookupHost(ctx, host)
+	}
+	if err != nil {
+		return nil, err
+	}
+	if len(addrs) == 0 {
+		return nil, ErrEmptyHostAddress
+	}
+	if cfg == nil {
+		cfg = &tls.Config{
+			ServerName: host,
+			MinVersion: tls.VersionTLS12,
+		}
+	}
+	var conn net.Conn
+	var tlsConn *tls.Conn
+	for _, a := range addrs {
+		if dialer.DefaultDialer.Timeout != 0 {
+			var cancel context.CancelFunc
+			ctx, cancel = context.WithTimeout(context.Background(), dialer.DefaultDialer.Timeout)
+			defer cancel()
+		} else if !dialer.DefaultDialer.Deadline.IsZero() {
+			var cancel context.CancelFunc
+			ctx, cancel = context.WithDeadline(context.Background(), dialer.DefaultDialer.Deadline)
+			defer cancel()
+		}
+		conn, err = dialer.DefaultDialer.DialContext(ctx, network, net.JoinHostPort(a, port))
+		if err != nil {
+			continue
+		}
+		tlsConn = tls.Client(terasu.NewConn(conn), cfg)
+		// re-init ctx due to deadline settings in tcp dial
+		if dialer.DefaultDialer.Timeout != 0 {
+			var cancel context.CancelFunc
+			ctx, cancel = context.WithTimeout(context.Background(), dialer.DefaultDialer.Timeout)
+			defer cancel()
+		} else if !dialer.DefaultDialer.Deadline.IsZero() {
+			var cancel context.CancelFunc
+			ctx, cancel = context.WithDeadline(context.Background(), dialer.DefaultDialer.Deadline)
+			defer cancel()
+		}
+		err = tlsConn.HandshakeContext(ctx)
+		if err == nil {
+			break
+		}
+		_ = tlsConn.Close()
+		tlsConn = nil
+		conn, err = dialer.DefaultDialer.DialContext(ctx, network, net.JoinHostPort(a, port))
+		if err != nil {
+			continue
+		}
+		tlsConn = tls.Client(terasu.NewConn(conn), cfg)
+		err = tlsConn.HandshakeContext(ctx)
+		if err == nil {
+			break
+		}
+		_ = tlsConn.Close()
+		tlsConn = nil
+	}
+	return tlsConn, err
+}