h2c

Documentation

Overview

Package h2c implements the unencrypted "h2c" form of HTTP/2.

The h2c protocol is the non-TLS version of HTTP/2 which is not available from net/http or golang.org/x/net/http2.

Index

• func NewHandler(h http.Handler, s *http2.Server) http.Handler

Examples

• NewHandler

Functions

func NewHandler

func NewHandler(h http.Handler, s *http2.Server) http.Handler

NewHandler returns an http.Handler that wraps h, intercepting any h2c traffic. If a request is an h2c connection, it's hijacked and redirected to s.ServeConn. Otherwise the returned Handler just forwards requests to h. This works because h2c is designed to be parseable as valid HTTP/1, but ignored by any HTTP server that does not handle h2c. Therefore we leverage the HTTP/1 compatible parts of the Go http library to parse and recognize h2c requests. Once a request is recognized as h2c, we hijack the connection and convert it to an HTTP/2 connection which is understandable to s.ServeConn. (s.ServeConn understands HTTP/2 except for the h2c part of it.)

The first request on an h2c connection is read entirely into memory before the Handler is called. To limit the memory consumed by this request, wrap the result of NewHandler in an http.MaxBytesHandler.

Example

handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
	fmt.Fprint(w, "Hello world")
})
h2s := &http2.Server{
	// ...
}
h1s := &http.Server{
	Addr:    ":8080",
	Handler: NewHandler(handler, h2s),
}
log.Fatal(h1s.ListenAndServe())