v6: DomainSearchList getter

Signed-off-by: Chris Koch <chrisko@google.com>

7 files changed, 42 insertions, 35 deletions

diff --git a/dhcpv6/dhcpv6message.go b/dhcpv6/dhcpv6message.go
index 8ba7943..56f8627 100644
--- a/dhcpv6/dhcpv6message.go
+++ b/dhcpv6/dhcpv6message.go
@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/insomniacslk/dhcp/iana"
+	"github.com/insomniacslk/dhcp/rfc1035label"
 	"github.com/u-root/u-root/pkg/rand"
 	"github.com/u-root/u-root/pkg/uio"
 )
@@ -130,6 +131,18 @@ func (mo MessageOptions) DNS() []net.IP {
 	return nil
 }
 
+// DomainSearchList returns the Domain List option as defined by RFC 3646.
+func (mo MessageOptions) DomainSearchList() *rfc1035label.Labels {
+	opt := mo.Options.GetOne(OptionDomainSearchList)
+	if opt == nil {
+		return nil
+	}
+	if dsl, ok := opt.(*optDomainSearchList); ok {
+		return dsl.DomainSearchList
+	}
+	return nil
+}
+
 // BootFileURL returns the Boot File URL option as defined by RFC 5970.
 func (mo MessageOptions) BootFileURL() string {
 	opt := mo.Options.GetOne(OptionBootfileURL)
diff --git a/dhcpv6/modifiers.go b/dhcpv6/modifiers.go
index ee2056f..14bfe51 100644
--- a/dhcpv6/modifiers.go
+++ b/dhcpv6/modifiers.go
@@ -94,12 +94,11 @@ func WithDNS(dnses ...net.IP) Modifier {
 // WithDomainSearchList adds or updates an OptDomainSearchList
 func WithDomainSearchList(searchlist ...string) Modifier {
 	return func(d DHCPv6) {
-		osl := OptDomainSearchList{
-			DomainSearchList: &rfc1035label.Labels{
+		d.UpdateOption(OptDomainSearchList(
+			&rfc1035label.Labels{
 				Labels: searchlist,
 			},
-		}
-		d.UpdateOption(&osl)
+		))
 	}
 }
 
diff --git a/dhcpv6/modifiers_test.go b/dhcpv6/modifiers_test.go
index e31cd29..b99d4a2 100644
--- a/dhcpv6/modifiers_test.go
+++ b/dhcpv6/modifiers_test.go
@@ -73,15 +73,11 @@ func TestWithDNS(t *testing.T) {
 
 func TestWithDomainSearchList(t *testing.T) {
 	var d Message
-	WithDomainSearchList([]string{
-		"slackware.it",
-		"dhcp.slackware.it",
-	}...)(&d)
+	WithDomainSearchList("slackware.it", "dhcp.slackware.it")(&d)
 	require.Equal(t, 1, len(d.Options.Options))
-	osl := d.Options.Options[0].(*OptDomainSearchList)
-	require.Equal(t, OptionDomainSearchList, osl.Code())
-	require.NotNil(t, osl.DomainSearchList)
-	labels := osl.DomainSearchList.Labels
+	osl := d.Options.DomainSearchList()
+	require.NotNil(t, osl)
+	labels := osl.Labels
 	require.Equal(t, 2, len(labels))
 	require.Equal(t, "slackware.it", labels[0])
 	require.Equal(t, "dhcp.slackware.it", labels[1])
diff --git a/dhcpv6/option_domainsearchlist.go b/dhcpv6/option_domainsearchlist.go
index 6bbe4e3..e71a8d5 100644
--- a/dhcpv6/option_domainsearchlist.go
+++ b/dhcpv6/option_domainsearchlist.go
@@ -6,31 +6,32 @@ import (
 	"github.com/insomniacslk/dhcp/rfc1035label"
 )
 
-// OptDomainSearchList list implements a OptionDomainSearchList option
-//
-// This module defines the OptDomainSearchList structure.
-// https://www.ietf.org/rfc/rfc3646.txt
-type OptDomainSearchList struct {
+// OptDomainSearchList returns a DomainSearchList option as defined by RFC 3646.
+func OptDomainSearchList(labels *rfc1035label.Labels) Option {
+	return &optDomainSearchList{DomainSearchList: labels}
+}
+
+type optDomainSearchList struct {
 	DomainSearchList *rfc1035label.Labels
 }
 
-func (op *OptDomainSearchList) Code() OptionCode {
+func (op *optDomainSearchList) Code() OptionCode {
 	return OptionDomainSearchList
 }
 
 // ToBytes marshals this option to bytes.
-func (op *OptDomainSearchList) ToBytes() []byte {
+func (op *optDomainSearchList) ToBytes() []byte {
 	return op.DomainSearchList.ToBytes()
 }
 
-func (op *OptDomainSearchList) String() string {
-	return fmt.Sprintf("OptDomainSearchList{searchlist=%v}", op.DomainSearchList.Labels)
+func (op *optDomainSearchList) String() string {
+	return fmt.Sprintf("DomainSearchList: %s", op.DomainSearchList)
 }
 
 // ParseOptDomainSearchList builds an OptDomainSearchList structure from a sequence
 // of bytes. The input data does not include option code and length bytes.
-func ParseOptDomainSearchList(data []byte) (*OptDomainSearchList, error) {
-	var opt OptDomainSearchList
+func parseOptDomainSearchList(data []byte) (*optDomainSearchList, error) {
+	var opt optDomainSearchList
 	var err error
 	opt.DomainSearchList, err = rfc1035label.FromBytes(data)
 	if err != nil {
diff --git a/dhcpv6/option_domainsearchlist_test.go b/dhcpv6/option_domainsearchlist_test.go
index b4d0195..433f710 100644
--- a/dhcpv6/option_domainsearchlist_test.go
+++ b/dhcpv6/option_domainsearchlist_test.go
@@ -12,13 +12,13 @@ func TestParseOptDomainSearchList(t *testing.T) {
 		7, 'e', 'x', 'a', 'm', 'p', 'l', 'e', 3, 'c', 'o', 'm', 0,
 		6, 's', 'u', 'b', 'n', 'e', 't', 7, 'e', 'x', 'a', 'm', 'p', 'l', 'e', 3, 'o', 'r', 'g', 0,
 	}
-	opt, err := ParseOptDomainSearchList(data)
+	opt, err := parseOptDomainSearchList(data)
 	require.NoError(t, err)
 	require.Equal(t, OptionDomainSearchList, opt.Code())
 	require.Equal(t, 2, len(opt.DomainSearchList.Labels))
 	require.Equal(t, "example.com", opt.DomainSearchList.Labels[0])
 	require.Equal(t, "subnet.example.org", opt.DomainSearchList.Labels[1])
-	require.Contains(t, opt.String(), "searchlist=[example.com subnet.example.org]", "String() should contain the correct domain search output")
+	require.Contains(t, opt.String(), "example.com subnet.example.org", "String() should contain the correct domain search output")
 }
 
 func TestOptDomainSearchListToBytes(t *testing.T) {
@@ -26,14 +26,14 @@ func TestOptDomainSearchListToBytes(t *testing.T) {
 		7, 'e', 'x', 'a', 'm', 'p', 'l', 'e', 3, 'c', 'o', 'm', 0,
 		6, 's', 'u', 'b', 'n', 'e', 't', 7, 'e', 'x', 'a', 'm', 'p', 'l', 'e', 3, 'o', 'r', 'g', 0,
 	}
-	opt := OptDomainSearchList{
-		DomainSearchList: &rfc1035label.Labels{
+	opt := OptDomainSearchList(
+		&rfc1035label.Labels{
 			Labels: []string{
 				"example.com",
 				"subnet.example.org",
 			},
 		},
-	}
+	)
 	require.Equal(t, expected, opt.ToBytes())
 }
 
@@ -42,6 +42,6 @@ func TestParseOptDomainSearchListInvalidLength(t *testing.T) {
 		7, 'e', 'x', 'a', 'm', 'p', 'l', 'e', 3, 'c', 'o', 'm', 0,
 		6, 's', 'u', 'b', 'n', 'e', 't', 7, 'e', // truncated
 	}
-	_, err := ParseOptDomainSearchList(data)
+	_, err := parseOptDomainSearchList(data)
 	require.Error(t, err, "A truncated OptDomainSearchList should return an error")
 }
diff --git a/dhcpv6/options.go b/dhcpv6/options.go
index 23a0ba9..9b76f6d 100644
--- a/dhcpv6/options.go
+++ b/dhcpv6/options.go
@@ -68,7 +68,7 @@ func ParseOption(code OptionCode, optData []byte) (Option, error) {
 	case OptionDNSRecursiveNameServer:
 		opt, err = parseOptDNS(optData)
 	case OptionDomainSearchList:
-		opt, err = ParseOptDomainSearchList(optData)
+		opt, err = parseOptDomainSearchList(optData)
 	case OptionIAPD:
 		opt, err = ParseOptIAForPrefixDelegation(optData)
 	case OptionIAPrefix:
diff --git a/netboot/netconf.go b/netboot/netconf.go
index 6f05e93..78ddff8 100644
--- a/netboot/netconf.go
+++ b/netboot/netconf.go
@@ -66,11 +66,9 @@ func GetNetConfFromPacketv6(d *dhcpv6.Message) (*NetConf, error) {
 	}
 	netconf.DNSServers = dns
 
-	opt := d.GetOneOption(dhcpv6.OptionDomainSearchList)
-	if opt != nil {
-		odomains := opt.(*dhcpv6.OptDomainSearchList)
-		// TODO should this be copied?
-		netconf.DNSSearchList = odomains.DomainSearchList.Labels
+	domains := d.Options.DomainSearchList()
+	if domains != nil {
+		netconf.DNSSearchList = domains.Labels
 	}
 
 	return &netconf, nil