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/sentry/socket/netstack/netstack.go | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'pkg/sentry/socket') diff --git a/pkg/sentry/socket/netstack/netstack.go b/pkg/sentry/socket/netstack/netstack.go index 0b64a24c3..335284f50 100644 --- a/pkg/sentry/socket/netstack/netstack.go +++ b/pkg/sentry/socket/netstack/netstack.go @@ -205,7 +205,8 @@ var Metrics = tcpip.Stats{ LinkLocalSource: mustCreateMetric("/netstack/ip/forwarding/link_local_source_address", "Number of IP packets received which could not be forwarded due to a link-local source address."), LinkLocalDestination: mustCreateMetric("/netstack/ip/forwarding/link_local_destination_address", "Number of IP packets received which could not be forwarded due to a link-local destination address."), ExtensionHeaderProblem: mustCreateMetric("/netstack/ip/forwarding/extension_header_problem", "Number of IP packets received which could not be forwarded due to a problem processing their IPv6 extension headers."), - PacketTooBig: mustCreateMetric("/netstack/ip/forwarding/packet_too_big", "Number of IP packets received which could not fit within the outgoing MTU."), + PacketTooBig: mustCreateMetric("/netstack/ip/forwarding/packet_too_big", "Number of IP packets received which could not be forwarded because they could not fit within the outgoing MTU."), + HostUnreachable: mustCreateMetric("/netstack/ip/forwarding/host_unreachable", "Number of IP packets received which could not be forwarded due to unresolvable next hop."), Errors: mustCreateMetric("/netstack/ip/forwarding/errors", "Number of IP packets which couldn't be forwarded."), }, }, -- cgit v1.2.3