From c384641b7c61358a3f65f7f600c342c658939493 Mon Sep 17 00:00:00 2001
From: Patricio Whittingslow <graded.sp@gmail.com>
Date: Sat, 21 Feb 2026 23:52:27 -0300
Subject: [PATCH] arp: fix runt frames by extending at ethernet level; discard
 blocking ARP queries after success/failure

---
 internet/stack-ethernet.go | 8 ++++++++
 x/xnet/stack-blocking.go   | 4 +++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/internet/stack-ethernet.go b/internet/stack-ethernet.go
index 3c0f4f3..6e1dad6 100644
--- a/internet/stack-ethernet.go
+++ b/internet/stack-ethernet.go
@@ -166,6 +166,14 @@ func (ls *StackEthernet) Encapsulate(carrierData []byte, offsetToIP, offsetToFra
 	*efrm.SourceHardwareAddr() = ls.mac
 	efrm.SetEtherType(ethernet.Type(h.proto))
 	n += 14
+	// Pad to minimum Ethernet frame size (60 bytes without CRC, 64 with).
+	// Frames shorter than this are "runt frames" and may be dropped by switches/routers
+	// according to 802.3 minimum length of 64 octets.
+	const minFrameSize = 60
+	for n < minFrameSize {
+		dst[n] = 0
+		n++
+	}
 	if ls.crcupdate != nil {
 		crc := ls.crcupdate(0, carrierData[offsetToFrame:offsetToFrame+n])
 		binary.LittleEndian.PutUint32(carrierData[offsetToFrame+n:], crc)
diff --git a/x/xnet/stack-blocking.go b/x/xnet/stack-blocking.go
index f4fc389..916191f 100644
--- a/x/xnet/stack-blocking.go
+++ b/x/xnet/stack-blocking.go
@@ -90,11 +90,13 @@ func (s StackBlocking) DoResolveHardwareAddress6(addr netip.Addr, timeout time.D
 		if err == nil {
 			break
 		} else if err = s.checkDeadline(deadline); err != nil {
-			return hw, err
+			break
 		}
 		time.Sleep(sleep)
 		err = errDeadlineExceed // Ensure that if iterations done error is returned.
 	}
+	ip4 := addr.As4()
+	s.async.arp.DiscardQuery(ip4[:])
 	return hw, err
 }