Update dependencies

vendor/tailscale.com/net/dns/resolvd.go

@@ -0,0 +1,128 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build openbsd
+
+package dns
+
+import (
+	"bytes"
+	"os"
+	"os/exec"
+	"regexp"
+	"strings"
+
+	"tailscale.com/net/dns/resolvconffile"
+	"tailscale.com/types/logger"
+)
+
+func newResolvdManager(logf logger.Logf, interfaceName string) (*resolvdManager, error) {
+	return &resolvdManager{
+		logf:   logf,
+		ifName: interfaceName,
+		fs:     directFS{},
+	}, nil
+}
+
+// resolvdManager is an OSConfigurator which uses route(1) to teach OpenBSD's
+// resolvd(8) about DNS servers.
+type resolvdManager struct {
+	logf   logger.Logf
+	ifName string
+	fs     directFS
+}
+
+func (m *resolvdManager) SetDNS(config OSConfig) error {
+	args := []string{
+		"nameserver",
+		m.ifName,
+	}
+
+	origResolv, err := m.readAndCopy(resolvConf, backupConf, 0644)
+	if err != nil {
+		return err
+	}
+	newResolvConf := removeSearchLines(origResolv)
+
+	for _, ns := range config.Nameservers {
+		args = append(args, ns.String())
+	}
+
+	var newSearch = []string{
+		"search",
+	}
+	for _, s := range config.SearchDomains {
+		newSearch = append(newSearch, s.WithoutTrailingDot())
+	}
+
+	if len(newSearch) > 1 {
+		newResolvConf = append(newResolvConf, []byte(strings.Join(newSearch, " "))...)
+	}
+
+	err = m.fs.WriteFile(resolvConf, newResolvConf, 0644)
+	if err != nil {
+		return err
+	}
+
+	cmd := exec.Command("/sbin/route", args...)
+	return cmd.Run()
+}
+
+func (m *resolvdManager) SupportsSplitDNS() bool {
+	return false
+}
+
+func (m *resolvdManager) GetBaseConfig() (OSConfig, error) {
+	cfg, err := m.readResolvConf()
+	if err != nil {
+		return OSConfig{}, err
+	}
+
+	return cfg, nil
+}
+
+func (m *resolvdManager) Close() error {
+	// resolvd handles teardown of nameservers so we only need to write back the original
+	// config and be done.
+
+	_, err := m.readAndCopy(backupConf, resolvConf, 0644)
+	if err != nil {
+		return err
+	}
+
+	return m.fs.Remove(backupConf)
+}
+
+func (m *resolvdManager) readAndCopy(a, b string, mode os.FileMode) ([]byte, error) {
+	orig, err := m.fs.ReadFile(a)
+	if err != nil {
+		return nil, err
+	}
+	err = m.fs.WriteFile(b, orig, mode)
+	if err != nil {
+		return nil, err
+	}
+
+	return orig, nil
+}
+
+func (m resolvdManager) readResolvConf() (config OSConfig, err error) {
+	b, err := m.fs.ReadFile(resolvConf)
+	if err != nil {
+		return OSConfig{}, err
+	}
+
+	rconf, err := resolvconffile.Parse(bytes.NewReader(b))
+	if err != nil {
+		return config, err
+	}
+	return OSConfig{
+		Nameservers:   rconf.Nameservers,
+		SearchDomains: rconf.SearchDomains,
+	}, nil
+}
+
+func removeSearchLines(orig []byte) []byte {
+	re := regexp.MustCompile(`(?m)^search\s+.+$`)
+	return re.ReplaceAll(orig, []byte(""))
+}