[ztpv4] add Opt60 (vc) parsing (#187)

1 files changed, 80 insertions, 0 deletions

diff --git a/dhcpv4/ztp/ztp.go b/dhcpv4/ztp/ztp.go
new file mode 100644
index 0000000..b899425
--- /dev/null
+++ b/dhcpv4/ztp/ztp.go
@@ -0,0 +1,80 @@
+package ztpv4
+
+import (
+	"errors"
+	"strings"
+
+	"github.com/insomniacslk/dhcp/dhcpv4"
+)
+
+// VendorData is optional data a particular vendor may or may not include
+// in the Vendor Class options.
+type VendorData struct {
+	VendorName string
+	Model      string
+	Serial     string
+}
+
+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) {
+	opt := packet.GetOneOption(dhcpv4.OptionClassIdentifier)
+	if opt == nil {
+		return nil, nil
+	}
+	vc := opt.(*dhcpv4.OptClassIdentifier).Identifier
+	vd := &VendorData{}
+
+	switch {
+	// Arista;DCS-7050S-64;01.23;JPE12221671
+	case strings.HasPrefix(vc, "Arista;"):
+		p := strings.Split(vc, ";")
+		if len(p) < 4 {
+			return nil, errVendorOptionMalformed
+		}
+
+		vd.VendorName = p[0]
+		vd.Model = p[1]
+		vd.Serial = p[3]
+		return vd, nil
+
+	// ZPESystems:NSC:002251623
+	case strings.HasPrefix(vc, "ZPESystems:"):
+		p := strings.Split(vc, ":")
+		if len(p) < 3 {
+			return nil, errVendorOptionMalformed
+		}
+
+		vd.VendorName = p[0]
+		vd.Model = p[1]
+		vd.Serial = p[2]
+		return vd, nil
+
+	// Juniper option 60 parsing is a bit more nuanced.  The following are all
+	// "valid" identifying stings for Juniper:
+	//    Juniper-ptx1000-DD576      <vendor>-<model>-<serial
+	//    Juniper-qfx10008           <vendor>-<model> (serial in hostname option)
+	//    Juniper-qfx10002-361-DN817 <vendor>-<model>-<serial> (model has a dash in it!)
+	case strings.HasPrefix(vc, "Juniper-"):
+		p := strings.Split(vc, "-")
+		if len(p) < 3 {
+			vd.Model = p[1]
+			if opt := packet.GetOneOption(dhcpv4.OptionHostName); opt != nil {
+				vd.Serial = opt.(*dhcpv4.OptHostName).HostName
+			} else {
+				return nil, errors.New("host name option is missing")
+			}
+		} else {
+			vd.Model = strings.Join(p[1:len(p)-1], "-")
+			vd.Serial = p[len(p)-1]
+		}
+
+		vd.VendorName = p[0]
+		return vd, nil
+	}
+
+	// We didn't match anything.
+	return nil, nil
+}