net/http: http2 client return EOF #13598

mattn · 2015-12-13T14:10:26Z

I'm trying to connect to https://dav.box.com/ with golang. It seems that box.com provide http2 protocol. But go's http2 client retrun EOF always. I debugged little and I make sure this occur on h2 protocol in TLSNextProto. So currently I'm disabling h2 like below.

http.DefaultTransport.(*http.Transport).TLSNextProto = make(map[string]func(string, *tls.Conn) http.RoundTripper)

mattn · 2015-12-13T14:10:50Z

/cc @bradfitz

bradfitz · 2015-12-13T19:19:48Z

Indeed! Thanks for the bug report.

brad5k:~ $ cat get.go

package main

import (
    "io"
    "log"
    "net/http"
    "os"
)

func main() {
    res, err := http.Get("https://dav.box.com/")
    if err != nil {
        log.Fatal(err)
    }
    log.Printf("Res: %#v", res)
    _, err = io.Copy(os.Stdout, res.Body)
    if err != nil {
        log.Fatal(err)
    }
}

With HTTP/2 enabled by default: (mix of error messages)

brad5k:~ $ go run get.go 
2015/12/13 11:19:14 Get https://dav.box.com/: EOF
exit status 1
brad5k:~ $ go run get.go 
2015/12/13 11:19:15 Get https://dav.box.com/: EOF
exit status 1
brad5k:~ $ go run get.go 
2015/12/13 11:19:17 Get https://dav.box.com/: read tcp 10.0.0.55:55327->74.112.184.85:443: read: connection reset by peer
exit status 1

With HTTP/2 explicitly disabled:

brad5k:~ $ GODEBUG=h2client=0 go run get.go
2015/12/13 11:18:13 Res: &http.Response{Status:"401 Unauthorized", StatusCode:401, Proto:"HTTP/1.1", ProtoMajor:1, ProtoMinor:1, Header:http.Header{"Content-Length":[]string{"242"}, "Date":[]string{"Sun, 13 Dec 2015 19:18:13 GMT"}, "Age":[]string{"0"}, "Connection":[]string{"keep-alive"}, "Server":[]string{"ATS"}, "Content-Type":[]string{"application/xml; charset=utf-8"}, "Www-Authenticate":[]string{"Basic realm=\"dav.box.com\""}}, Body:(*http.bodyEOFSignal)(0xc8201380c0), ContentLength:242, TransferEncoding:[]string(nil), Close:false, Trailer:http.Header(nil), Request:(*http.Request)(0xc8200ce000), TLS:(*tls.ConnectionState)(0xc82035f080)}
<?xml version="1.0" encoding="utf-8"?>
<d:error xmlns:d="DAV:" xmlns:s="http://sabredav.org/ns">
  <s:exception>Sabre_DAV_Exception_NotAuthenticated</s:exception>
  <s:message>No basic authentication headers were found</s:message>
</d:error>

mattn · 2015-12-14T13:47:35Z

Yes, I got same result.

bradfitz · 2015-12-14T17:48:46Z

I found the problem. https://dav.box.com does not speak HTTP/2. But we advertise in our TLS connection that we speak "h2" but we never mention that we also speak "http/1.1", and Box's frontend recognizes ALPN or NPN enough to know that they can't handle "h2", so they hang up on us.

The fix is to declare that we also speak "http/1.1" as a fallback.

Easy fix.

RFC 7301 defines the ALPN protocol "http/1.1". We weren't sending that, so at least one site (dav.box.com) was rejecting our connection, since they didn't support the only protocol we advertised ("h2"). Had we advertised nothing, they would've assumed http/1.1 implicitly. This CL also hooks up the verbose logging knob to the GODEBUG environment variable. Updates golang/go#13598 (fixed when this is copied into std) Change-Id: I6ea1231d0d0f0bc767caa0458237eefd943d9d3d Reviewed-on: https://go-review.googlesource.com/17754 Reviewed-by: Ian Lance Taylor <iant@golang.org>

golang/go#13598

bradfitz self-assigned this Dec 13, 2015

bradfitz added this to the Go1.6 milestone Dec 13, 2015

bradfitz changed the title ~~http2 client return EOF~~ net/http: http2 client return EOF Dec 13, 2015

bradfitz closed this as completed in 0954c80 Dec 14, 2015

mattn added a commit to mattn/davc that referenced this issue Dec 15, 2015

remove workaround.

63ecfb0

golang/go#13598

golang locked and limited conversation to collaborators Dec 14, 2016

gopherbot added the FrozenDueToAge label Dec 14, 2016

rsc unassigned bradfitz Jun 23, 2022

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net/http: http2 client return EOF #13598

net/http: http2 client return EOF #13598

mattn commented Dec 13, 2015

mattn commented Dec 13, 2015

bradfitz commented Dec 13, 2015

mattn commented Dec 14, 2015

bradfitz commented Dec 14, 2015

net/http: http2 client return EOF #13598

net/http: http2 client return EOF #13598

Comments

mattn commented Dec 13, 2015

mattn commented Dec 13, 2015

bradfitz commented Dec 13, 2015

mattn commented Dec 14, 2015

bradfitz commented Dec 14, 2015