Support SetHeaderOrder and SetPseudoHeaderOrder for HTTP/3 Request

internal/http3/request_writer.go

@@ -7,6 +7,7 @@ import (
 	"io"
 	"net"
 	"net/http"
+	"net/http/httptrace"
 	"strconv"
 	"strings"
 	"sync"
@@ -70,6 +71,25 @@ func (w *requestWriter) writeHeaders(wr io.Writer, req *http.Request, gzip bool,
 	return err
 }
 
+var reqWriteExcludeHeader = map[string]bool{
+	// Host is :authority, already sent.
+	// Content-Length is automatic.
+	"host":           true,
+	"content-length": true,
+	// 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.
+	"connection":        true,
+	"proxy-connection":  true,
+	"transfer-encoding": true,
+	"upgrade":           true,
+	"keep-alive":        true,
+	// Ignore header order keys which is only used internally.
+	header.HeaderOderKey:       true,
+	header.PseudoHeaderOderKey: true,
+}
+
 // copied from net/transport.go
 // Modified to support Extended CONNECT:
 // Contrary to what the godoc for the http.Request says,
@@ -121,37 +141,73 @@ func (w *requestWriter) encodeHeaders(req *http.Request, addGzipHeader bool, tra
 	}
 
 	enumerateHeaders := func(f func(name, value string)) {
+		var writeHeader func(name string, value ...string)
+		var kvs []header.KeyValues
+		sort := false
+		if req.Header != nil && len(req.Header[header.PseudoHeaderOderKey]) > 0 {
+			writeHeader = func(name string, value ...string) {
+				kvs = append(kvs, header.KeyValues{
+					Key:    name,
+					Values: value,
+				})
+			}
+			sort = true
+		} else {
+			writeHeader = func(name string, value ...string) {
+				for _, v := range value {
+					f(name, v)
+				}
+			}
+		}
 		// 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]).
-		f(":authority", host)
-		f(":method", req.Method)
+		writeHeader(":authority", host)
+		writeHeader(":method", req.Method)
 		if req.Method != http.MethodConnect || isExtendedConnect {
-			f(":path", path)
-			f(":scheme", req.URL.Scheme)
+			writeHeader(":path", path)
+			writeHeader(":scheme", req.URL.Scheme)
 		}
 		if isExtendedConnect {
-			f(":protocol", req.Proto)
+			writeHeader(":protocol", req.Proto)
 		}
+
+		if sort {
+			header.SortKeyValues(kvs, req.Header[header.PseudoHeaderOderKey])
+			for _, kv := range kvs {
+				for _, v := range kv.Values {
+					f(kv.Key, v)
+				}
+			}
+		}
+
+		if req.Header != nil && len(req.Header[header.HeaderOderKey]) > 0 {
+			sort = true
+			kvs = nil
+			writeHeader = func(name string, value ...string) {
+				kvs = append(kvs, header.KeyValues{
+					Key:    name,
+					Values: value,
+				})
+			}
+		} else {
+			sort = false
+			writeHeader = func(name string, value ...string) {
+				for _, v := range value {
+					f(name, v)
+				}
+			}
+		}
+
 		if trailers != "" {
-			f("trailer", trailers)
+			writeHeader("trailer", trailers)
 		}
 
 		var didUA bool
 		for k, vv := range req.Header {
-			if strings.EqualFold(k, "host") || strings.EqualFold(k, "content-length") {
-				// Host is :authority, already sent.
-				// Content-Length is automatic, set below.
-				continue
-			} else if strings.EqualFold(k, "connection") || strings.EqualFold(k, "proxy-connection") ||
-				strings.EqualFold(k, "transfer-encoding") || strings.EqualFold(k, "upgrade") ||
-				strings.EqualFold(k, "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.
+			if reqWriteExcludeHeader[strings.ToLower(k)] {
 				continue
 			} else if strings.EqualFold(k, "user-agent") {
 				// Match Go's http1 behavior: at most one
@@ -170,17 +226,26 @@ func (w *requestWriter) encodeHeaders(req *http.Request, addGzipHeader bool, tra
 			}
 
 			for _, v := range vv {
-				f(k, v)
+				writeHeader(k, v)
 			}
 		}
 		if shouldSendReqContentLength(req.Method, contentLength) {
-			f("content-length", strconv.FormatInt(contentLength, 10))
+			writeHeader("content-length", strconv.FormatInt(contentLength, 10))
 		}
 		if addGzipHeader {
-			f("accept-encoding", "gzip")
+			writeHeader("accept-encoding", "gzip")
 		}
 		if !didUA {
-			f("user-agent", header.DefaultUserAgent)
+			writeHeader("user-agent", header.DefaultUserAgent)
+		}
+
+		if sort {
+			header.SortKeyValues(kvs, req.Header[header.HeaderOderKey])
+			for _, kv := range kvs {
+				for _, v := range kv.Values {
+					f(kv.Key, v)
+				}
+			}
 		}
 	}
 
@@ -199,19 +264,19 @@ func (w *requestWriter) encodeHeaders(req *http.Request, addGzipHeader bool, tra
 	// 	return errRequestHeaderListSize
 	// }
 
-	// trace := httptrace.ContextClientTrace(req.Context())
-	// traceHeaders := traceHasWroteHeaderField(trace)
+	trace := httptrace.ContextClientTrace(req.Context())
+	traceHeaders := traceHasWroteHeaderField(trace)
 
 	// Header list size is ok. Write the headers.
-	enumerateHeaders(func(name, value string) {
+	enumerateHeaders(func(name, vlue string) {
 		name = strings.ToLower(name)
 		for _, dump := range dumps {
 			dump.DumpRequestHeader([]byte(fmt.Sprintf("%s: %s\r\n", name, value)))
 		}
 		w.encoder.WriteField(qpack.HeaderField{Name: name, Value: value})
-		// if traceHeaders {
-		// 	traceWroteHeaderField(trace, name, value)
-		// }
+		if traceHeaders {
+			trace.WroteHeaderField(name, []string{value})
+		}
 	})
 
 	for _, dump := range dumps {

internal/http3/trace.go

@@ -0,0 +1,7 @@
+package http3
+
+import "net/http/httptrace"
+
+func traceHasWroteHeaderField(trace *httptrace.ClientTrace) bool {
+	return trace != nil && trace.WroteHeaderField != nil
+}