Add dhcp Opt 124(vivc) parsing to ztp (#425)

* Add dhcp Opt 124(vivc) parsing to ztp

Signed-off-by: Hariharakumar Narasimhakumar <hhkumar@fb.com>

2 files changed, 103 insertions, 10 deletions

diff --git a/dhcpv4/ztpv4/ztp.go b/dhcpv4/ztpv4/ztp.go
index 1bcb44f..43bc0e6 100644
--- a/dhcpv4/ztpv4/ztp.go
+++ b/dhcpv4/ztpv4/ztp.go
@@ -1,10 +1,12 @@
 package ztpv4
 
 import (
+	"bytes"
 	"errors"
 	"strings"
 
 	"github.com/insomniacslk/dhcp/dhcpv4"
+	"github.com/insomniacslk/dhcp/iana"
 )
 
 // VendorData is optional data a particular vendor may or may not include
@@ -15,16 +17,10 @@ type VendorData struct {
 
 var errVendorOptionMalformed = errors.New("malformed vendor option")
 
-// ParseVendorData will try to parse dhcp4 options looking for more
-// specific vendor data (like model, serial number, etc).
-func ParseVendorData(packet *dhcpv4.DHCPv4) (*VendorData, error) {
-	vc := packet.ClassIdentifier()
-	if len(vc) == 0 {
-		return nil, errors.New("vendor options not found")
-	}
+func parseClassIdentifier(packet *dhcpv4.DHCPv4) (*VendorData, error) {
 	vd := &VendorData{}
 
-	switch {
+	switch vc := packet.ClassIdentifier(); {
 	// Arista;DCS-7050S-64;01.23;JPE12221671
 	case strings.HasPrefix(vc, "Arista;"):
 		p := strings.Split(vc, ";")
@@ -71,6 +67,57 @@ func ParseVendorData(packet *dhcpv4.DHCPv4) (*VendorData, error) {
 		return vd, nil
 	}
 
-	// We didn't match anything.
+	return nil, nil
+}
+
+func parseVIVC(packet *dhcpv4.DHCPv4) (*VendorData, error) {
+	vd := &VendorData{}
+
+	for _, id := range packet.VIVC() {
+		if id.EntID == uint32(iana.EntIDCiscoSystems) {
+			vd.VendorName = iana.EntIDCiscoSystems.String()
+			//SN:0;PID:R-IOSXRV9000-CC
+			for _, f := range bytes.Split(id.Data, []byte(";")) {
+				p := bytes.Split(f, []byte(":"))
+				if len(p) != 2 {
+					return nil, errVendorOptionMalformed
+				}
+
+				switch string(p[0]) {
+				case "SN":
+					vd.Serial = string(p[1])
+				case "PID":
+					vd.Model = string(p[1])
+				}
+			}
+			return vd, nil
+		}
+	}
+
+	return nil, nil
+}
+
+// ParseVendorData will try to parse dhcp4 options looking for more
+// specific vendor data (like model, serial number, etc).
+func ParseVendorData(packet *dhcpv4.DHCPv4) (*VendorData, error) {
+	vd, err := parseClassIdentifier(packet)
+	if err != nil {
+		return nil, err
+	}
+
+	// If VendorData is set, return early
+	if vd != nil {
+		return vd, nil
+	}
+
+	vd, err = parseVIVC(packet)
+	if err != nil {
+		return nil, err
+	}
+
+	if vd != nil {
+		return vd, nil
+	}
+
 	return nil, errors.New("no known ZTP vendor found")
 }
diff --git a/dhcpv4/ztpv4/ztp_test.go b/dhcpv4/ztpv4/ztp_test.go
index 6e050d9..d0b002f 100644
--- a/dhcpv4/ztpv4/ztp_test.go
+++ b/dhcpv4/ztpv4/ztp_test.go
@@ -4,10 +4,11 @@ import (
 	"testing"
 
 	"github.com/insomniacslk/dhcp/dhcpv4"
+	"github.com/insomniacslk/dhcp/iana"
 	"github.com/stretchr/testify/require"
 )
 
-func TestParseV4VendorClass(t *testing.T) {
+func TestParseClassIdentifier(t *testing.T) {
 	tt := []struct {
 		name         string
 		vc, hostname string
@@ -70,3 +71,48 @@ func TestParseV4VendorClass(t *testing.T) {
 		})
 	}
 }
+
+func TestParseVIVC(t *testing.T) {
+	tt := []struct {
+		name  string
+		vivc  string
+		entID iana.EntID
+		want  *VendorData
+		fail  bool
+	}{
+		{
+			name:  "cisco",
+			entID: iana.EntIDCiscoSystems,
+			vivc:  "SN:0;PID:R-IOSXRV9000-CC",
+			want:  &VendorData{VendorName: "Cisco Systems", Model: "R-IOSXRV9000-CC", Serial: "0"},
+		},
+		{
+			name:  "ciscoMultipleColonDelimiters",
+			entID: iana.EntIDCiscoSystems,
+			vivc:  "SN:0:123;PID:R-IOSXRV9000-CC:456",
+			fail:  true,
+		},
+	}
+
+	for _, tc := range tt {
+		t.Run(tc.name, func(t *testing.T) {
+			packet, err := dhcpv4.New()
+			if err != nil {
+				t.Fatalf("failed to creat dhcpv4 packet object: %v", err)
+			}
+
+			if tc.vivc != "" {
+				vivc := dhcpv4.VIVCIdentifier{EntID: uint32(tc.entID), Data: []byte(tc.vivc)}
+				packet.UpdateOption(dhcpv4.OptVIVC(vivc))
+			}
+
+			vd, err := ParseVendorData(packet)
+			if tc.fail {
+				require.Error(t, err)
+			} else {
+				require.NoError(t, err)
+				require.Equal(t, tc.want, vd)
+			}
+		})
+	}
+}