all: fix go-flags

README.md

@@ -76,7 +76,7 @@ Application Options:
       --private-subnets=           Private subnets to use for reverse DNS lookups of private addresses
       --bogus-nxdomain=            Transform the responses containing at least a single IP that matches specified addresses and CIDRs into
                                    NXDOMAIN.  Can be specified multiple times.
-      --hosts-files=               List of paths to the hosts files to sresolve from.
+      --hosts-files=               List of paths to the hosts files relative to the root, can be specified multiple times
       --timeout=                   Timeout for outbound DNS queries to remote upstream servers in a human-readable form (default: 10s)
       --cache-min-ttl=             Minimum TTL value for DNS entries, in seconds. Capped at 3600. Artificially extending TTLs should only be
                                    done with careful consideration.
@@ -101,7 +101,7 @@ Application Options:
       --edns                       Use EDNS Client Subnet extension
       --dns64                      If specified, dnsproxy will act as a DNS64 server
       --use-private-rdns           If specified, use private upstreams for reverse DNS lookups of private addresses
-      --hosts-file-enabled         If specified, use hosts files for resolving
+      --hosts-file-enabled=        If specified, use hosts files for resolving (default: true)
 
 Help Options:
   -h, --help                       Show this help message

go.mod

@@ -8,7 +8,7 @@ require (
 	github.com/ameshkov/dnsstamps v1.0.3
 	github.com/beefsack/go-rate v0.0.0-20220214233405-116f4ca011a0
 	github.com/bluele/gcache v0.0.2
-	github.com/jessevdk/go-flags v1.5.0
+	github.com/jessevdk/go-flags v1.6.1
 	github.com/miekg/dns v1.1.58
 	github.com/patrickmn/go-cache v2.1.0+incompatible
 	github.com/quic-go/quic-go v0.44.0

go.sum

@@ -26,8 +26,8 @@ github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/pprof v0.0.0-20240130152714-0ed6a68c8d9e h1:E+3PBMCXn0ma79O7iCrne0iUpKtZ7rIcZvoz+jNtNtw=
 github.com/google/pprof v0.0.0-20240130152714-0ed6a68c8d9e/go.mod h1:czg5+yv1E0ZGTi6S6vVK1mke0fV+FaUhNGcd6VRS9Ik=
-github.com/jessevdk/go-flags v1.5.0 h1:1jKYvbxEjfUl0fmqTCOfonvskHHXMjBySTLW4y9LFvc=
-github.com/jessevdk/go-flags v1.5.0/go.mod h1:Fw0T6WPc1dYxT4mKEZRfG5kJhaTDP9pj1c2EWnYs/m4=
+github.com/jessevdk/go-flags v1.6.1 h1:Cvu5U8UGrLay1rZfv/zP7iLpSHGUZ/Ou68T0iX1bBK4=
+github.com/jessevdk/go-flags v1.6.1/go.mod h1:Mk8T1hIAWpOiJiHa9rJASDK2UGWji0EuPGBnNLMooyc=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
@@ -64,7 +64,6 @@ golang.org/x/net v0.28.0 h1:a9JDOJc5GMUJ0+UDqmLT86WiEy7iWyIhz8gz8E4e5hE=
 golang.org/x/net v0.28.0/go.mod h1:yqtgsTWOOnlGLG9GFRrK3++bGOUEkNBoHZc8MEDWPNg=
 golang.org/x/sync v0.8.0 h1:3NFvSEYkUoMifnESzZl15y791HH1qU2xm6eCJU5ZPXQ=
 golang.org/x/sync v0.8.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
-golang.org/x/sys v0.0.0-20210320140829-1e4c9ba3b0c4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.24.0 h1:Twjiwq9dn6R1fQcyiK+wQyHWfaz/BJB+YIpzU/Cv3Xg=
 golang.org/x/sys v0.24.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/text v0.17.0 h1:XtiM5bkSOt+ewxlOE/aE/AKEHibwj/6gvWMl9Rsh0Qc=

internal/cmd/config.go

@@ -152,7 +152,7 @@ func (opts *Options) initUpstreams(
 		Logger:             l,
 		HTTPVersions:       httpVersions,
 		InsecureSkipVerify: opts.Insecure,
-		Timeout:            timeout,
+		Timeout:            timeout.Duration,
 	}
 	boot, err := initBootstrap(ctx, l, opts.BootstrapDNS, bootOpts)
 	if err != nil {
@@ -164,7 +164,7 @@ func (opts *Options) initUpstreams(
 		HTTPVersions:       httpVersions,
 		InsecureSkipVerify: opts.Insecure,
 		Bootstrap:          boot,
-		Timeout:            timeout,
+		Timeout:            timeout.Duration,
 	}
 	upstreams := loadServersList(opts.Upstreams)
 
@@ -177,7 +177,7 @@ func (opts *Options) initUpstreams(
 		Logger:       l,
 		HTTPVersions: httpVersions,
 		Bootstrap:    boot,
-		Timeout:      min(defaultLocalTimeout, timeout),
+		Timeout:      min(defaultLocalTimeout, timeout.Duration),
 	}
 	privateUpstreams := loadServersList(opts.PrivateRDNSUpstreams)
 

internal/cmd/options.go

@@ -22,6 +22,49 @@ const (
 	argVersion    = "--version"
 )
 
+// decodableBool is a boolean that can be unmarshaled from a flags.
+//
+// TODO(e.burkov):  This is a workaround for go-flags, see
+// https://github.com/AdguardTeam/dnsproxy/issues/182.
+type decodableBool struct {
+	value bool
+}
+
+// type check
+var _ goFlags.Unmarshaler = (*decodableBool)(nil)
+
+// UnmarshalFlag implements the [goFlags.Unmarshaler] interface for
+// *decodableBool.
+func (b *decodableBool) UnmarshalFlag(text string) (err error) {
+	switch text {
+	case "true":
+		b.value = true
+	case "false":
+		b.value = false
+	default:
+		return fmt.Errorf("invalid boolean value: %s", text)
+	}
+
+	return nil
+}
+
+// decodableDuration is a duration that can be unmarshaled from a flags.
+//
+// TODO(e.burkov):  This is a workaround for go-flags, see
+// https://github.com/AdguardTeam/dnsproxy/issues/182.
+type decodableDuration struct {
+	timeutil.Duration
+}
+
+// type check
+var _ goFlags.Unmarshaler = (*decodableDuration)(nil)
+
+// UnmarshalFlag implements the [goFlags.Unmarshaler] interface for
+// *decodableDuration.
+func (d *decodableDuration) UnmarshalFlag(text string) (err error) {
+	return d.UnmarshalText([]byte(text))
+}
+
 // Options represents console arguments.  For further additions, please do not
 // use the default option since it will cause some problems when config files
 // are used.
@@ -109,11 +152,11 @@ type Options struct {
 	BogusNXDomain []string `yaml:"bogus-nxdomain" long:"bogus-nxdomain" description:"Transform the responses containing at least a single IP that matches specified addresses and CIDRs into NXDOMAIN.  Can be specified multiple times."`
 
 	// HostsFiles is the list of paths to the hosts files to resolve from.
-	HostsFiles []string `yaml:"hosts-files" long:"hosts-files" description:"List of paths to the hosts files to resolve from."`
+	HostsFiles []string `yaml:"hosts-files" long:"hosts-files" description:"List of paths to the hosts files relative to the root, can be specified multiple times"`
 
 	// Timeout for outbound DNS queries to remote upstream servers in a
 	// human-readable form.  Default is 10s.
-	Timeout timeutil.Duration `yaml:"timeout" long:"timeout" description:"Timeout for outbound DNS queries to remote upstream servers in a human-readable form" default:"10s"`
+	Timeout decodableDuration `yaml:"timeout" long:"timeout" description:"Timeout for outbound DNS queries to remote upstream servers in a human-readable form" default:"10s"`
 
 	// CacheMinTTL is the minimum TTL value for caching DNS entries, in seconds.
 	// It overrides the TTL value from the upstream server, if the one is less.
@@ -195,7 +238,7 @@ type Options struct {
 
 	// HostsFileEnabled controls whether hosts files are used for resolving or
 	// not.
-	HostsFileEnabled bool `yaml:"hosts-file-enabled" long:"hosts-file-enabled" description:"If specified, use hosts files for resolving" optional:"yes" optional-value:"true"`
+	HostsFileEnabled decodableBool `yaml:"hosts-file-enabled" long:"hosts-file-enabled" description:"If specified, use hosts files for resolving" default:"true"`
 }
 
 // parseOptions returns options parsed from the command args or config file.
@@ -243,10 +286,14 @@ func parseOptions() (opts *Options, exitCode int, err error) {
 // hostsFiles returns the list of hosts files to resolve from.  It's empty if
 // resolving from hosts files is disabled.
 func (opts *Options) hostsFiles(ctx context.Context, l *slog.Logger) (paths []string, err error) {
-	if !opts.HostsFileEnabled {
+	if !opts.HostsFileEnabled.value {
+		l.DebugContext(ctx, "hosts files are disabled")
+
 		return nil, nil
 	}
 
+	l.DebugContext(ctx, "hosts files are enabled")
+
 	if len(opts.HostsFiles) > 0 {
 		return opts.HostsFiles, nil
 	}

internal/handler/hosts.go

@@ -2,6 +2,7 @@ package handler
 
 import (
 	"context"
+	"fmt"
 	"io/fs"
 	"net/netip"
 	"slices"
@@ -42,6 +43,7 @@ func readHosts(fsys fs.FS, paths []string) (strg hostsfile.Storage, err error) {
 	for _, path := range paths {
 		err = readHostsFile(defaultStrg, fsys, path)
 		if err != nil {
+			// Don't wrap the error since it's informative enough as is.
 			errs = append(errs, err)
 		}
 	}
@@ -70,7 +72,12 @@ func readHostsFile(strg *hostsfile.DefaultStorage, fsys fs.FS, path string) (err
 	}
 	defer func() { err = errors.WithDeferred(err, f.Close()) }()
 
-	return hostsfile.Parse(strg, f, nil)
+	err = hostsfile.Parse(strg, f, nil)
+	if err != nil {
+		return fmt.Errorf("parsing hosts file %q: %w", path, err)
+	}
+
+	return nil
 }
 
 // resolveFromHosts resolves the DNS query from the hosts file.  It fills the