Add MLNX-OS ZTPv6 vendor data parsing

Signed-off-by: Gerardo Poggio <gepoggio@fb.com>

3 files changed, 113 insertions, 2 deletions

diff --git a/dhcpv6/ztpv6/mellanox.go b/dhcpv6/ztpv6/mellanox.go
new file mode 100644
index 0000000..3ed8b43
--- /dev/null
+++ b/dhcpv6/ztpv6/mellanox.go
@@ -0,0 +1,37 @@
+package ztpv6
+
+import (
+	"errors"
+
+	"github.com/insomniacslk/dhcp/dhcpv6"
+	"github.com/insomniacslk/dhcp/iana"
+)
+
+type MlnxSubOption uint16
+
+const (
+	MlnxSubOptionModel   MlnxSubOption = 1
+	MlnxSubOptionPartNum MlnxSubOption = 2
+	MlnxSubOptionSerial  MlnxSubOption = 3
+	MlnxSubOptionMac     MlnxSubOption = 4
+	MlnxSubOptionProfile MlnxSubOption = 5
+	MlnxSubOptionRelease MlnxSubOption = 6
+)
+
+func getMellanoxVendorData(vendorOptsOption *dhcpv6.OptVendorOpts) (*VendorData, error) {
+	vd := VendorData{}
+	vd.VendorName = iana.EnterpriseIDMellanoxTechnologiesLTD.String()
+	for _, opt := range vendorOptsOption.VendorOpts {
+		switch MlnxSubOption(opt.Code()) {
+		case MlnxSubOptionSerial:
+			vd.Serial = string(opt.ToBytes())
+		case MlnxSubOptionModel:
+			vd.Model = string(opt.ToBytes())
+		}
+	}
+	if (vd.Serial == "") || (vd.Model == "") {
+		return nil, errors.New("couldn't parse Mellanox sub-option for serial or model")
+	}
+
+	return &vd, nil
+}
diff --git a/dhcpv6/ztpv6/mellanox_test.go b/dhcpv6/ztpv6/mellanox_test.go
new file mode 100644
index 0000000..29293d1
--- /dev/null
+++ b/dhcpv6/ztpv6/mellanox_test.go
@@ -0,0 +1,66 @@
+package ztpv6
+
+import (
+	"testing"
+
+	"github.com/insomniacslk/dhcp/dhcpv6"
+	"github.com/insomniacslk/dhcp/iana"
+	"github.com/stretchr/testify/require"
+)
+
+func TestParseMellanoxVendorData(t *testing.T) {
+	tt := []struct {
+		name       string
+		vendorOpts []dhcpv6.Option
+		want       *VendorData
+		fail       bool
+	}{
+		{name: "empty", fail: true},
+		{
+			name: "ok",
+			fail: false,
+			vendorOpts: []dhcpv6.Option{
+				&dhcpv6.OptionGeneric{OptionData: []byte("SomeModel"), OptionCode: dhcpv6.OptionCode(MlnxSubOptionModel)},
+				&dhcpv6.OptionGeneric{OptionData: []byte("SomeModel-1234"), OptionCode: dhcpv6.OptionCode(MlnxSubOptionPartNum)},
+				&dhcpv6.OptionGeneric{OptionData: []byte("ABC1234"), OptionCode: dhcpv6.OptionCode(MlnxSubOptionSerial)},
+				&dhcpv6.OptionGeneric{OptionData: []byte("1.2.3"), OptionCode: dhcpv6.OptionCode(MlnxSubOptionRelease)},
+			},
+			want: &VendorData{
+				VendorName: iana.EnterpriseIDMellanoxTechnologiesLTD.String(),
+				Model:      "SomeModel",
+				Serial:     "ABC1234",
+			},
+		},
+		{
+			name: "no model",
+			fail: true,
+			vendorOpts: []dhcpv6.Option{
+				&dhcpv6.OptionGeneric{OptionData: []byte("ABC1234"), OptionCode: dhcpv6.OptionCode(MlnxSubOptionSerial)},
+			},
+			want: nil,
+		},
+	}
+
+	for _, tc := range tt {
+		t.Run(tc.name, func(t *testing.T) {
+			packet, err := dhcpv6.NewMessage()
+			if err != nil {
+				t.Fatalf("failed to creat dhcpv6 packet object: %v", err)
+			}
+
+			packet.AddOption(&dhcpv6.OptVendorOpts{
+				VendorOpts: tc.vendorOpts, EnterpriseNumber: uint32(iana.EnterpriseIDMellanoxTechnologiesLTD)})
+
+			vd, err := ParseVendorData(packet)
+			if err != nil && !tc.fail {
+				t.Errorf("unexpected failure: %v", err)
+			}
+
+			if vd != nil {
+				require.Equal(t, *tc.want, *vd, "comparing vendor option data")
+			} else {
+				require.Equal(t, tc.want, vd, "comparing vendor option data")
+			}
+		})
+	}
+}
diff --git a/dhcpv6/ztpv6/parse_vendor_options.go b/dhcpv6/ztpv6/parse_vendor_options.go
index f1508fd..caa4e2f 100644
--- a/dhcpv6/ztpv6/parse_vendor_options.go
+++ b/dhcpv6/ztpv6/parse_vendor_options.go
@@ -33,8 +33,16 @@ func ParseVendorData(packet dhcpv6.DHCPv6) (*VendorData, error) {
 	vData := []string{}
 
 	if opt17 != nil {
-		vo := opt17.(*dhcpv6.OptVendorOpts).VendorOpts
-		for _, opt := range vo {
+		vendorOptsOption := opt17.(*dhcpv6.OptVendorOpts)
+
+		// MLNX-OS has the relevant information spread over different sub-options
+		// of option 17 so the usual approach doesn't work
+		if vendorOptsOption.EnterpriseNumber == uint32(iana.EnterpriseIDMellanoxTechnologiesLTD) {
+			return getMellanoxVendorData(vendorOptsOption)
+		}
+
+		// rest of vendors use a single sub-option so we stringify them and parse them below
+		for _, opt := range vendorOptsOption.VendorOpts {
 			vData = append(vData, string(opt.(*dhcpv6.OptionGeneric).OptionData))
 		}
 	} else {