net: UDP sockets on windows error on receive due to ICMP TTL

[raggi]

Go version

go1.22.5

Output of go env in your module/workspace:

GO111MODULE=''
GOARCH='arm64'
GOBIN=''
GOCACHE='/Users/raggi/Library/Caches/go-build'
GOENV='/Users/raggi/Library/Application Support/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='arm64'
GOHOSTOS='darwin'
GOINSECURE=''
GOMODCACHE='/Users/raggi/go/pkg/mod'
GONOPROXY='ra66i.org/raggi,rag.pub/raggi'
GONOSUMDB='ra66i.org/raggi,rag.pub/raggi'
GOOS='darwin'
GOPATH='/Users/raggi/go'
GOPRIVATE='ra66i.org/raggi,rag.pub/raggi'
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/Users/raggi/.cache/tailscale-go'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/Users/raggi/.cache/tailscale-go/pkg/tool/darwin_arm64'
GOVCS=''
GOVERSION='go1.22.5'
GCCGO='gccgo'
AR='ar'
CC='clang'
CXX='clang++'
CGO_ENABLED='1'
GOMOD='/dev/null'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -ffile-prefix-map=/var/folders/bb/dyr_1n6j575g8nq85nmnfbt00000gn/T/go-build2102863150=/tmp/go-build -gno-record-gcc-switches -fno-common'

What did you do?

We have observed errors in RecvFrom as a result of ICMP replies to UDP sockets on Windows, which is an unexpected behavior resulting from a Windows socket behavior quirk.

What did you see happen?

Socket recv generated an error as a result of ICMP replies to earlier sent packets.

What did you expect to see?

Socket recv should not generate an error due to ICMP received.

Detail & Proposal

Background: a prior round of this issue was fixed in 3114bd6 which addressed one case of ICMP reply (https://www.betaarchive.com/wiki/index.php?title=Microsoft_KB_Archive/263823), but there are two. The Godot project ran into this issue as well, and describes the issue and fix here: godotengine/godot@397b01d

The net package only disables SIO_UDP_CONNRESET, but not SIO_UDP_NETRESET, as such there are still ICMP responses that can lead to wsarecvfrom: The connection has been broken due to keep-alive activity detecting a failure while the operation was in progress.

We should set SIO_UDP_NETRESET as well as SIO_UDP_CONNRESET in order to get behavior that is most similar to bsd sockets on the other major platforms, where asynchronous ICMP replies are ignored unless explicitly opted in to.

[gabyhelp]

Related Issues and Documentation

• x/net/icmp: listen icmp in Windows not work properly #38427
• internal/poll: sending a zero-byte-payload UDP packet on Windows is a no-op #26668 (closed)
• net: TCP RST handling is unreliable on OSX #50254
• net: ReadFromUDP falls into busy waiting on empty UDP packet #59704 (closed)
• x/net/icmp: PacketConn.ReadFrom on an unprivileged PacketConn on darwin returns the entire IP packet #47369
• net: no checksum processing on loopback #23599 (closed)
• net: UDPConn.ReadFrom returns error for oversized datagram on Windows #14074 (closed)

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[seankhliao]

cc @golang/windows

[gopherbot]

Change https://go.dev/cl/601038 mentions this issue: windows: add SIO_UDP_NETRESET for net/ to use

[gopherbot]

Change https://go.dev/cl/601397 mentions this issue: internal/poll: disable SIO_UDP_NETRESET on Windows

[alexbrainman]

The Godot project ran into this issue as well, and describes the issue and fix here: godotengine/godot@397b01d

Is there some official documentation for this?

I searched for SIO_UDP_NETRESET, but I could not find anything.

Or are we supposed to assume that https://github.com/godotengine/godot know how it works.

Thank you.

Alex