From 5d932860ec8531e84e058b68cd0ee10c3949cabf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tobias=20B=C3=B6hm?= <tobias.boehm@hetzner-cloud.de>
Date: Wed, 26 Apr 2023 17:55:58 +0200
Subject: [PATCH] Fix DHCPv4 header field name hops

The DHCPv4 header field "HardwareOpts" is misleading. This fields
original name by RFC 2131, which just takes it from RFC 951, is "hops".
It has never changed meaning and still reflects number of relay agents
it passed, as described in RFC 951 section 8.

This commit changes the name of the field "HardwareOpts" to "RelayHops".
---
 layers/dhcp_test.go | 4 ++--
 layers/dhcpv4.go    | 6 +++---
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/layers/dhcp_test.go b/layers/dhcp_test.go
index c9b32b8c5..f9c6eb5ec 100644
--- a/layers/dhcp_test.go
+++ b/layers/dhcp_test.go
@@ -129,8 +129,8 @@ func testDHCPEqual(t *testing.T, d1, d2 *DHCPv4) {
 	if d1.HardwareLen != d2.HardwareLen {
 		t.Errorf("expected HardwareLen=%v, got %v", d1.HardwareLen, d2.HardwareLen)
 	}
-	if d1.HardwareOpts != d2.HardwareOpts {
-		t.Errorf("expected HardwareOpts=%v, got %v", d1.HardwareOpts, d2.HardwareOpts)
+	if d1.RelayHops != d2.RelayHops {
+		t.Errorf("expected RelayHops=%v, got %v", d1.RelayHops, d2.RelayHops)
 	}
 	if d1.Xid != d2.Xid {
 		t.Errorf("expected Xid=%v, got %v", d1.Xid, d2.Xid)
diff --git a/layers/dhcpv4.go b/layers/dhcpv4.go
index 67c80b7d5..f0105b8db 100644
--- a/layers/dhcpv4.go
+++ b/layers/dhcpv4.go
@@ -87,7 +87,7 @@ type DHCPv4 struct {
 	Operation    DHCPOp
 	HardwareType LinkType
 	HardwareLen  uint8
-	HardwareOpts uint8
+	RelayHops    uint8
 	Xid          uint32
 	Secs         uint16
 	Flags        uint16
@@ -132,7 +132,7 @@ func (d *DHCPv4) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error
 	d.Operation = DHCPOp(data[0])
 	d.HardwareType = LinkType(data[1])
 	d.HardwareLen = data[2]
-	d.HardwareOpts = data[3]
+	d.RelayHops = data[3]
 	d.Xid = binary.BigEndian.Uint32(data[4:8])
 	d.Secs = binary.BigEndian.Uint16(data[8:10])
 	d.Flags = binary.BigEndian.Uint16(data[10:12])
@@ -209,7 +209,7 @@ func (d *DHCPv4) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.Serialize
 		d.HardwareLen = uint8(len(d.ClientHWAddr))
 	}
 	data[2] = d.HardwareLen
-	data[3] = d.HardwareOpts
+	data[3] = d.RelayHops
 	binary.BigEndian.PutUint32(data[4:8], d.Xid)
 	binary.BigEndian.PutUint16(data[8:10], d.Secs)
 	binary.BigEndian.PutUint16(data[10:12], d.Flags)