From 727a17d07bc2c8042bd882dd6fcc3001a47933c9 Mon Sep 17 00:00:00 2001
From: Pablo Mazzini <pmazzini@gmail.com>
Date: Tue, 31 Jul 2018 17:02:36 +0200
Subject: add OptHostName

---
 dhcpv4/option_domain_name.go    |  6 ++---
 dhcpv4/option_host_name.go      | 49 +++++++++++++++++++++++++++++++++++++++++
 dhcpv4/option_host_name_test.go | 41 ++++++++++++++++++++++++++++++++++
 dhcpv4/options.go               |  2 ++
 4 files changed, 95 insertions(+), 3 deletions(-)
 create mode 100644 dhcpv4/option_host_name.go
 create mode 100644 dhcpv4/option_host_name_test.go

(limited to 'dhcpv4')

diff --git a/dhcpv4/option_domain_name.go b/dhcpv4/option_domain_name.go
index 71d7ef1..e876b05 100644
--- a/dhcpv4/option_domain_name.go
+++ b/dhcpv4/option_domain_name.go
@@ -2,10 +2,10 @@ package dhcpv4
 
 import "fmt"
 
-// This option implements the server domani name option
+// This option implements the domain name option
 // https://tools.ietf.org/html/rfc2132
 
-// OptDomainName represents an option encapsulating the server identifier.
+// OptDomainName represents an option encapsulating the domain name.
 type OptDomainName struct {
 	DomainName string
 }
@@ -13,7 +13,7 @@ type OptDomainName struct {
 // ParseOptDomainName returns a new OptDomainName from a byte
 // stream, or error if any.
 func ParseOptDomainName(data []byte) (*OptDomainName, error) {
-	if len(data) < 2 {
+	if len(data) < 3 {
 		return nil, ErrShortByteStream
 	}
 	code := OptionCode(data[0])
diff --git a/dhcpv4/option_host_name.go b/dhcpv4/option_host_name.go
new file mode 100644
index 0000000..a922a2b
--- /dev/null
+++ b/dhcpv4/option_host_name.go
@@ -0,0 +1,49 @@
+package dhcpv4
+
+import "fmt"
+
+// This option implements the host name option
+// https://tools.ietf.org/html/rfc2132
+
+// OptHostName represents an option encapsulating the host name.
+type OptHostName struct {
+	HostName string
+}
+
+// ParseOptHostName returns a new OptHostName from a byte stream, or error if
+// any.
+func ParseOptHostName(data []byte) (*OptHostName, error) {
+	if len(data) < 3 {
+		return nil, ErrShortByteStream
+	}
+	code := OptionCode(data[0])
+	if code != OptionHostName {
+		return nil, fmt.Errorf("expected code %v, got %v", OptionHostName, code)
+	}
+	length := int(data[1])
+	if len(data) < 2+length {
+		return nil, ErrShortByteStream
+	}
+	return &OptHostName{HostName: string(data[2 : 2+length])}, nil
+}
+
+// Code returns the option code.
+func (o *OptHostName) Code() OptionCode {
+	return OptionHostName
+}
+
+// ToBytes returns a serialized stream of bytes for this option.
+func (o *OptHostName) ToBytes() []byte {
+	return append([]byte{byte(o.Code()), byte(o.Length())}, []byte(o.HostName)...)
+}
+
+// String returns a human-readable string.
+func (o *OptHostName) String() string {
+	return fmt.Sprintf("Host Name -> %v", o.HostName)
+}
+
+// Length returns the length of the data portion (excluding option code an byte
+// length).
+func (o *OptHostName) Length() int {
+	return len(o.HostName)
+}
diff --git a/dhcpv4/option_host_name_test.go b/dhcpv4/option_host_name_test.go
new file mode 100644
index 0000000..7f99100
--- /dev/null
+++ b/dhcpv4/option_host_name_test.go
@@ -0,0 +1,41 @@
+package dhcpv4
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestOptHostNameInterfaceMethods(t *testing.T) {
+	o := OptHostName{HostName: "foo"}
+	require.Equal(t, OptionHostName, o.Code(), "Code")
+	require.Equal(t, 3, o.Length(), "Length")
+	require.Equal(t, []byte{byte(OptionHostName), 3, 'f', 'o', 'o'}, o.ToBytes(), "ToBytes")
+}
+
+func TestParseOptHostName(t *testing.T) {
+	data := []byte{byte(OptionHostName), 4, 't', 'e', 's', 't'}
+	o, err := ParseOptHostName(data)
+	require.NoError(t, err)
+	require.Equal(t, &OptHostName{HostName: "test"}, o)
+
+	// Short byte stream
+	data = []byte{byte(OptionHostName)}
+	_, err = ParseOptHostName(data)
+	require.Error(t, err, "should get error from short byte stream")
+
+	// Wrong code
+	data = []byte{54, 2, 1, 1}
+	_, err = ParseOptHostName(data)
+	require.Error(t, err, "should get error from wrong code")
+
+	// Bad length
+	data = []byte{byte(OptionHostName), 6, 1, 1, 1}
+	_, err = ParseOptHostName(data)
+	require.Error(t, err, "should get error from bad length")
+}
+
+func TestOptHostNameString(t *testing.T) {
+	o := OptHostName{HostName: "testy test"}
+	require.Equal(t, "Host Name -> testy test", o.String())
+}
diff --git a/dhcpv4/options.go b/dhcpv4/options.go
index 760bc98..4903ab3 100644
--- a/dhcpv4/options.go
+++ b/dhcpv4/options.go
@@ -44,6 +44,8 @@ func ParseOption(data []byte) (Option, error) {
 		opt, err = ParseOptSubnetMask(data)
 	case OptionRouter:
 		opt, err = ParseOptRouter(data)
+	case OptionHostName:
+		opt, err = ParseOptDomainName(data)
 	case OptionRequestedIPAddress:
 		opt, err = ParseOptRequestedIPAddress(data)
 	case OptionIPAddressLeaseTime:
-- 
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