x/sys/unix: add support for L2TPIP sockaddr on Linux #37787
Description
What version of Go are you using (go version)?
$ go version go version go1.13.7 linux/amd64
Does this issue reproduce with the latest release?
Yes
What operating system and processor architecture are you using (go env)?
go env Output
$ go env GO111MODULE="" GOARCH="amd64" GOBIN="" GOCACHE="/home/tom/.cache/go-build" GOENV="/home/tom/.config/go/env" GOEXE="" GOFLAGS="" GOHOSTARCH="amd64" GOHOSTOS="linux" GONOPROXY="" GONOSUMDB="" GOOS="linux" GOPATH="/home/tom/go" GOPRIVATE="" GOPROXY="https://proxy.golang.org,direct" GOROOT="/usr/local/go" GOSUMDB="sum.golang.org" GOTMPDIR="" GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64" GCCGO="gccgo" AR="ar" CC="gcc" CXX="g++" CGO_ENABLED="1" GOMOD="" CGO_CFLAGS="-g -O2" CGO_CPPFLAGS="" CGO_CXXFLAGS="-g -O2" CGO_FFLAGS="-g -O2" CGO_LDFLAGS="-g -O2" PKG_CONFIG="pkg-config" GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build096416278=/tmp/go-build -gno-record-gcc-switches"
What did you do?
Linux kernel supports L2TPv3 (RFC3931) IP-encapsulated tunnels using two special sockaddr structures which include the L2TP control connection ID. These structures "struct sockaddr_l2tpip" and "struct sockaddr_l2tpip6" are not currently represented in x/sys/unix, meaning that Go programs cannot conveniently create L2TPv3 IP encapsulated tunnels.
The unix package should be extended to include types for the L2TPIP-specific sockaddr structures.