reverseproxy: Always remove hop-by-hop headers

See golang/go#46313 Based on https://github.com/golang/go/commit/950fa11c4cb01a145bb07eeb167d90a1846061b3

Matthew Holt committed Jun 4, 2021 at 15:21 UTC 2a8109468ce8520fa96e8a5139a350a1a68cbd26

1 file changed +7 -11

modules/caddyhttp/reverseproxy/reverseproxy.go

+7 -11

@@ -504,18 +504,14 @@ func (h Handler) prepareRequest(req *http.Request) error {

504 // Remove hop-by-hop headers to the backend. Especially

505 // important is "Connection" because we want a persistent

506 // connection, regardless of what the client sent to us.

507 + // Issue golang/go#46313: don't skip if field is empty.

508 for _, h := range hopHeaders {

508 - hv := req.Header.Get(h)

509 - if hv == "" {

510 - continue

511 - }

512 - if h == "Te" && hv == "trailers" {

513 - // Issue golang/go#21096: tell backend applications that

514 - // care about trailer support that we support

515 - // trailers. (We do, but we don't go out of

516 - // our way to advertise that unless the

517 - // incoming client request thought it was

518 - // worth mentioning)

509 + // Issue golang/go#21096: tell backend applications that care about trailer support

510 + // that we support trailers. (We do, but we don't go out of our way to

511 + // advertise that unless the incoming client request thought it was worth

512 + // mentioning.)

513 + if h == "Te" && httpguts.HeaderValuesContainsToken(req.Header["Te"], "trailers") {

514 + req.Header.Set("Te", "trailers")

515 continue

516 }

517 req.Header.Del(h)