From b8b43f70c898861a6fd642ded069dd33d35f17f9 Mon Sep 17 00:00:00 2001 From: Nick Brown Date: Wed, 19 May 2021 12:09:54 -0700 Subject: Send ICMP errors when link address resolution fails Before this change, we would silently drop packets when link resolution failed. This change brings us into line with RFC 792 (IPv4) and RFC 4443 (IPv6), both of which specify that gateways should return an ICMP error to the sender when link resolution fails. PiperOrigin-RevId: 374699789 --- pkg/tcpip/network/internal/ip/stats.go | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'pkg/tcpip/network/internal/ip') diff --git a/pkg/tcpip/network/internal/ip/stats.go b/pkg/tcpip/network/internal/ip/stats.go index 0c2b62127..40ab21cb6 100644 --- a/pkg/tcpip/network/internal/ip/stats.go +++ b/pkg/tcpip/network/internal/ip/stats.go @@ -42,6 +42,10 @@ type MultiCounterIPForwardingStats struct { // were too big for the outgoing MTU. PacketTooBig tcpip.MultiCounterStat + // HostUnreachable is the number of IP packets received which could not be + // successfully forwarded due to an unresolvable next hop. + HostUnreachable tcpip.MultiCounterStat + // ExtensionHeaderProblem is the number of IP packets which were dropped // because of a problem encountered when processing an IPv6 extension // header. @@ -61,6 +65,7 @@ func (m *MultiCounterIPForwardingStats) Init(a, b *tcpip.IPForwardingStats) { m.ExtensionHeaderProblem.Init(a.ExtensionHeaderProblem, b.ExtensionHeaderProblem) m.PacketTooBig.Init(a.PacketTooBig, b.PacketTooBig) m.ExhaustedTTL.Init(a.ExhaustedTTL, b.ExhaustedTTL) + m.HostUnreachable.Init(a.HostUnreachable, b.HostUnreachable) } // LINT.ThenChange(:MultiCounterIPForwardingStats, ../../../tcpip.go:IPForwardingStats) -- cgit v1.2.3