x/net/http2/h2c: h2cHandler does not respect server read/readheader/write timeouts

[milesbxf]

What version of Go are you using (go version)?

$ go version
go version go1.17.6 darwin/amd64

Does this issue reproduce with the latest release?

Yes (see playground link below)

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GO111MODULE="auto"
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/milesbryant/Library/Caches/go-build"
GOENV="/Users/milesbryant/Library/Application Support/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOINSECURE=""
GOMODCACHE="/Users/milesbryant/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="darwin"
GOPATH="/Users/milesbryant"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/Cellar/go@1.16/1.16.13/libexec"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go@1.16/1.16.13/libexec/pkg/tool/darwin_amd64"
GOVCS=""
GOVERSION="go1.17.6"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
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"

What did you do?

Reproduction in Go playground

• Set up a http2.Server and wrap a slow handler in h2c.NewHandler. Set http.Server.WriteTimeout that we expect to hit before the handler returns
• Send a h2c request

What did you expect to see?

An EOF error indicating that the server hit the WriteTimeout and reset the connection.
This is what we see for both plain http.Server, and http2.Server for full HTTP/2 with TLS.

What did you see instead?

The h2c request succeeds even though the handler takes much longer than the WriteTimeout.

[milesbxf]

In http2-land, it looks like the server timeouts are set via http2.ServeConnOpts.BaseConfig (which is a *http.Server which we copy config from).

This gets set for regular http2.Servers via http2.ConfigureServer

However, in h2cHandler.ServeHTTP we leave ServeConnOpts.BaseConfig as nil: https://github.com/golang/net/blob/2871e0cb64e47e47ba7466fad6e11562caf99563/http2/h2c/h2c.go#L87

I'm very happy to have a go at fixing this, but I'd love some guidance on what you think the best way forwards would be. The first challenge I can see is that the h2c package doesn't currently know anything about a *http.Server.

Perhaps we could:

• add a new constructor h2c.NewHandlerFromServer(h http.Handler, hs *http.Server, h2s *http2.Server)
• maintain a pointer to h2s as a hs field onh2cHandler
• call ServeConn with &http2.ServeConnOpts{..., BaseConfig: s.hs}

cc @neild

[AlexanderYastrebov]

Perhaps we could

This is what we did in our attempt zalando/skipper#1868 to fix some of the h2c long-standing issues

[AlexanderYastrebov]

I think this was fixed by golang/net#139