// encodeHeaders encodes an http.Header. If keys is not nil, then (k, h[k])
// is encoded only only if k is in keys.
func encodeHeaders(enc *hpack.Encoder, h http.Header, keys []string) {
if keys == nil {
sorter := sorterPool.Get().(*sorter)
// Using defer here, since the returned keys from the
// sorter.Keys method is only valid until the sorter
// is returned:
defer sorterPool.Put(sorter)
keys = sorter.Keys(h)
}
for _, k := range keys {
vv := h[k]
k = lowerHeader(k)
if !validWireHeaderFieldName(k) {
// Skip it as backup paranoia. Per
// golang.org/issue/14048, these should
// already be rejected at a higher level.
continue
}
isTE := k == "transfer-encoding"
for _, v := range vv {
if !httplex.ValidHeaderFieldValue(v) {
// TODO: return an error? golang.org/issue/14048
// For now just omit it.
continue
}
// TODO: more of "8.1.2.2 Connection-Specific Header Fields"
if isTE && v != "trailers" {
continue
}
encKV(enc, k, v)
}
}
}
// readMetaFrame returns 0 or more CONTINUATION frames from fr and
// merge them into into the provided hf and returns a MetaHeadersFrame
// with the decoded hpack values.
func (fr *Framer) readMetaFrame(hf *HeadersFrame) (*MetaHeadersFrame, error) {
if fr.AllowIllegalReads {
return nil, errors.New("illegal use of AllowIllegalReads with ReadMetaHeaders")
}
mh := &MetaHeadersFrame{
HeadersFrame: hf,
}
var remainSize = fr.maxHeaderListSize()
var sawRegular bool
var invalid error // pseudo header field errors
hdec := fr.ReadMetaHeaders
hdec.SetEmitEnabled(true)
hdec.SetMaxStringLength(fr.maxHeaderStringLen())
hdec.SetEmitFunc(func(hf hpack.HeaderField) {
if VerboseLogs && logFrameReads {
log.Printf("http2: decoded hpack field %+v", hf)
}
if !httplex.ValidHeaderFieldValue(hf.Value) {
invalid = headerFieldValueError(hf.Value)
}
isPseudo := strings.HasPrefix(hf.Name, ":")
if isPseudo {
if sawRegular {
invalid = errPseudoAfterRegular
}
} else {
sawRegular = true
if !validWireHeaderFieldName(hf.Name) {
invalid = headerFieldNameError(hf.Name)
}
}
if invalid != nil {
hdec.SetEmitEnabled(false)
return
}
size := hf.Size()
if size > remainSize {
hdec.SetEmitEnabled(false)
mh.Truncated = true
return
}
remainSize -= size
mh.Fields = append(mh.Fields, hf)
})
// Lose reference to MetaHeadersFrame:
defer hdec.SetEmitFunc(func(hf hpack.HeaderField) {})
var hc headersOrContinuation = hf
for {
frag := hc.HeaderBlockFragment()
if _, err := hdec.Write(frag); err != nil {
return nil, ConnectionError(ErrCodeCompression)
}
if hc.HeadersEnded() {
break
}
if f, err := fr.ReadFrame(); err != nil {
return nil, err
} else {
hc = f.(*ContinuationFrame) // guaranteed by checkFrameOrder
}
}
mh.HeadersFrame.headerFragBuf = nil
mh.HeadersFrame.invalidate()
if err := hdec.Close(); err != nil {
return nil, ConnectionError(ErrCodeCompression)
}
if invalid != nil {
fr.errDetail = invalid
if VerboseLogs {
log.Printf("http2: invalid header: %v", invalid)
}
return nil, StreamError{mh.StreamID, ErrCodeProtocol, invalid}
}
if err := mh.checkPseudos(); err != nil {
fr.errDetail = err
if VerboseLogs {
log.Printf("http2: invalid pseudo headers: %v", err)
}
return nil, StreamError{mh.StreamID, ErrCodeProtocol, err}
}
return mh, nil
}
// requires cc.mu be held.
func (cc *ClientConn) encodeHeaders(req *http.Request, addGzipHeader bool, trailers string, contentLength int64) ([]byte, error) {
cc.hbuf.Reset()
host := req.Host
if host == "" {
host = req.URL.Host
}
// Check for any invalid headers and return an error before we
// potentially pollute our hpack state. (We want to be able to
// continue to reuse the hpack encoder for future requests)
for k, vv := range req.Header {
if !httplex.ValidHeaderFieldName(k) {
return nil, fmt.Errorf("invalid HTTP header name %q", k)
}
for _, v := range vv {
if !httplex.ValidHeaderFieldValue(v) {
return nil, fmt.Errorf("invalid HTTP header value %q for header %q", v, k)
}
}
}
// 8.1.2.3 Request Pseudo-Header Fields
// The :path pseudo-header field includes the path and query parts of the
// target URI (the path-absolute production and optionally a '?' character
// followed by the query production (see Sections 3.3 and 3.4 of
// [RFC3986]).
cc.writeHeader(":authority", host)
cc.writeHeader(":method", req.Method)
if req.Method != "CONNECT" {
cc.writeHeader(":path", req.URL.RequestURI())
cc.writeHeader(":scheme", "https")
}
if trailers != "" {
cc.writeHeader("trailer", trailers)
}
var didUA bool
for k, vv := range req.Header {
lowKey := strings.ToLower(k)
switch lowKey {
case "host", "content-length":
// Host is :authority, already sent.
// Content-Length is automatic, set below.
continue
case "connection", "proxy-connection", "transfer-encoding", "upgrade", "keep-alive":
// Per 8.1.2.2 Connection-Specific Header
// Fields, don't send connection-specific
// fields. We have already checked if any
// are error-worthy so just ignore the rest.
continue
case "user-agent":
// Match Go's http1 behavior: at most one
// User-Agent. If set to nil or empty string,
// then omit it. Otherwise if not mentioned,
// include the default (below).
didUA = true
if len(vv) < 1 {
continue
}
vv = vv[:1]
if vv[0] == "" {
continue
}
}
for _, v := range vv {
cc.writeHeader(lowKey, v)
}
}
if shouldSendReqContentLength(req.Method, contentLength) {
cc.writeHeader("content-length", strconv.FormatInt(contentLength, 10))
}
if addGzipHeader {
cc.writeHeader("accept-encoding", "gzip")
}
if !didUA {
cc.writeHeader("user-agent", defaultUserAgent)
}
return cc.hbuf.Bytes(), nil
}