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-rw-r--r--vendor/golang.org/x/net/http2/frame.go1614
1 files changed, 1614 insertions, 0 deletions
diff --git a/vendor/golang.org/x/net/http2/frame.go b/vendor/golang.org/x/net/http2/frame.go
new file mode 100644
index 00000000..514c126c
--- /dev/null
+++ b/vendor/golang.org/x/net/http2/frame.go
@@ -0,0 +1,1614 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package http2
+
+import (
+ "bytes"
+ "encoding/binary"
+ "errors"
+ "fmt"
+ "io"
+ "log"
+ "strings"
+ "sync"
+
+ "golang.org/x/net/http/httpguts"
+ "golang.org/x/net/http2/hpack"
+)
+
+const frameHeaderLen = 9
+
+var padZeros = make([]byte, 255) // zeros for padding
+
+// A FrameType is a registered frame type as defined in
+// http://http2.github.io/http2-spec/#rfc.section.11.2
+type FrameType uint8
+
+const (
+ FrameData FrameType = 0x0
+ FrameHeaders FrameType = 0x1
+ FramePriority FrameType = 0x2
+ FrameRSTStream FrameType = 0x3
+ FrameSettings FrameType = 0x4
+ FramePushPromise FrameType = 0x5
+ FramePing FrameType = 0x6
+ FrameGoAway FrameType = 0x7
+ FrameWindowUpdate FrameType = 0x8
+ FrameContinuation FrameType = 0x9
+)
+
+var frameName = map[FrameType]string{
+ FrameData: "DATA",
+ FrameHeaders: "HEADERS",
+ FramePriority: "PRIORITY",
+ FrameRSTStream: "RST_STREAM",
+ FrameSettings: "SETTINGS",
+ FramePushPromise: "PUSH_PROMISE",
+ FramePing: "PING",
+ FrameGoAway: "GOAWAY",
+ FrameWindowUpdate: "WINDOW_UPDATE",
+ FrameContinuation: "CONTINUATION",
+}
+
+func (t FrameType) String() string {
+ if s, ok := frameName[t]; ok {
+ return s
+ }
+ return fmt.Sprintf("UNKNOWN_FRAME_TYPE_%d", uint8(t))
+}
+
+// Flags is a bitmask of HTTP/2 flags.
+// The meaning of flags varies depending on the frame type.
+type Flags uint8
+
+// Has reports whether f contains all (0 or more) flags in v.
+func (f Flags) Has(v Flags) bool {
+ return (f & v) == v
+}
+
+// Frame-specific FrameHeader flag bits.
+const (
+ // Data Frame
+ FlagDataEndStream Flags = 0x1
+ FlagDataPadded Flags = 0x8
+
+ // Headers Frame
+ FlagHeadersEndStream Flags = 0x1
+ FlagHeadersEndHeaders Flags = 0x4
+ FlagHeadersPadded Flags = 0x8
+ FlagHeadersPriority Flags = 0x20
+
+ // Settings Frame
+ FlagSettingsAck Flags = 0x1
+
+ // Ping Frame
+ FlagPingAck Flags = 0x1
+
+ // Continuation Frame
+ FlagContinuationEndHeaders Flags = 0x4
+
+ FlagPushPromiseEndHeaders Flags = 0x4
+ FlagPushPromisePadded Flags = 0x8
+)
+
+var flagName = map[FrameType]map[Flags]string{
+ FrameData: {
+ FlagDataEndStream: "END_STREAM",
+ FlagDataPadded: "PADDED",
+ },
+ FrameHeaders: {
+ FlagHeadersEndStream: "END_STREAM",
+ FlagHeadersEndHeaders: "END_HEADERS",
+ FlagHeadersPadded: "PADDED",
+ FlagHeadersPriority: "PRIORITY",
+ },
+ FrameSettings: {
+ FlagSettingsAck: "ACK",
+ },
+ FramePing: {
+ FlagPingAck: "ACK",
+ },
+ FrameContinuation: {
+ FlagContinuationEndHeaders: "END_HEADERS",
+ },
+ FramePushPromise: {
+ FlagPushPromiseEndHeaders: "END_HEADERS",
+ FlagPushPromisePadded: "PADDED",
+ },
+}
+
+// a frameParser parses a frame given its FrameHeader and payload
+// bytes. The length of payload will always equal fh.Length (which
+// might be 0).
+type frameParser func(fc *frameCache, fh FrameHeader, payload []byte) (Frame, error)
+
+var frameParsers = map[FrameType]frameParser{
+ FrameData: parseDataFrame,
+ FrameHeaders: parseHeadersFrame,
+ FramePriority: parsePriorityFrame,
+ FrameRSTStream: parseRSTStreamFrame,
+ FrameSettings: parseSettingsFrame,
+ FramePushPromise: parsePushPromise,
+ FramePing: parsePingFrame,
+ FrameGoAway: parseGoAwayFrame,
+ FrameWindowUpdate: parseWindowUpdateFrame,
+ FrameContinuation: parseContinuationFrame,
+}
+
+func typeFrameParser(t FrameType) frameParser {
+ if f := frameParsers[t]; f != nil {
+ return f
+ }
+ return parseUnknownFrame
+}
+
+// A FrameHeader is the 9 byte header of all HTTP/2 frames.
+//
+// See http://http2.github.io/http2-spec/#FrameHeader
+type FrameHeader struct {
+ valid bool // caller can access []byte fields in the Frame
+
+ // Type is the 1 byte frame type. There are ten standard frame
+ // types, but extension frame types may be written by WriteRawFrame
+ // and will be returned by ReadFrame (as UnknownFrame).
+ Type FrameType
+
+ // Flags are the 1 byte of 8 potential bit flags per frame.
+ // They are specific to the frame type.
+ Flags Flags
+
+ // Length is the length of the frame, not including the 9 byte header.
+ // The maximum size is one byte less than 16MB (uint24), but only
+ // frames up to 16KB are allowed without peer agreement.
+ Length uint32
+
+ // StreamID is which stream this frame is for. Certain frames
+ // are not stream-specific, in which case this field is 0.
+ StreamID uint32
+}
+
+// Header returns h. It exists so FrameHeaders can be embedded in other
+// specific frame types and implement the Frame interface.
+func (h FrameHeader) Header() FrameHeader { return h }
+
+func (h FrameHeader) String() string {
+ var buf bytes.Buffer
+ buf.WriteString("[FrameHeader ")
+ h.writeDebug(&buf)
+ buf.WriteByte(']')
+ return buf.String()
+}
+
+func (h FrameHeader) writeDebug(buf *bytes.Buffer) {
+ buf.WriteString(h.Type.String())
+ if h.Flags != 0 {
+ buf.WriteString(" flags=")
+ set := 0
+ for i := uint8(0); i < 8; i++ {
+ if h.Flags&(1<<i) == 0 {
+ continue
+ }
+ set++
+ if set > 1 {
+ buf.WriteByte('|')
+ }
+ name := flagName[h.Type][Flags(1<<i)]
+ if name != "" {
+ buf.WriteString(name)
+ } else {
+ fmt.Fprintf(buf, "0x%x", 1<<i)
+ }
+ }
+ }
+ if h.StreamID != 0 {
+ fmt.Fprintf(buf, " stream=%d", h.StreamID)
+ }
+ fmt.Fprintf(buf, " len=%d", h.Length)
+}
+
+func (h *FrameHeader) checkValid() {
+ if !h.valid {
+ panic("Frame accessor called on non-owned Frame")
+ }
+}
+
+func (h *FrameHeader) invalidate() { h.valid = false }
+
+// frame header bytes.
+// Used only by ReadFrameHeader.
+var fhBytes = sync.Pool{
+ New: func() interface{} {
+ buf := make([]byte, frameHeaderLen)
+ return &buf
+ },
+}
+
+// ReadFrameHeader reads 9 bytes from r and returns a FrameHeader.
+// Most users should use Framer.ReadFrame instead.
+func ReadFrameHeader(r io.Reader) (FrameHeader, error) {
+ bufp := fhBytes.Get().(*[]byte)
+ defer fhBytes.Put(bufp)
+ return readFrameHeader(*bufp, r)
+}
+
+func readFrameHeader(buf []byte, r io.Reader) (FrameHeader, error) {
+ _, err := io.ReadFull(r, buf[:frameHeaderLen])
+ if err != nil {
+ return FrameHeader{}, err
+ }
+ return FrameHeader{
+ Length: (uint32(buf[0])<<16 | uint32(buf[1])<<8 | uint32(buf[2])),
+ Type: FrameType(buf[3]),
+ Flags: Flags(buf[4]),
+ StreamID: binary.BigEndian.Uint32(buf[5:]) & (1<<31 - 1),
+ valid: true,
+ }, nil
+}
+
+// A Frame is the base interface implemented by all frame types.
+// Callers will generally type-assert the specific frame type:
+// *HeadersFrame, *SettingsFrame, *WindowUpdateFrame, etc.
+//
+// Frames are only valid until the next call to Framer.ReadFrame.
+type Frame interface {
+ Header() FrameHeader
+
+ // invalidate is called by Framer.ReadFrame to make this
+ // frame's buffers as being invalid, since the subsequent
+ // frame will reuse them.
+ invalidate()
+}
+
+// A Framer reads and writes Frames.
+type Framer struct {
+ r io.Reader
+ lastFrame Frame
+ errDetail error
+
+ // lastHeaderStream is non-zero if the last frame was an
+ // unfinished HEADERS/CONTINUATION.
+ lastHeaderStream uint32
+
+ maxReadSize uint32
+ headerBuf [frameHeaderLen]byte
+
+ // TODO: let getReadBuf be configurable, and use a less memory-pinning
+ // allocator in server.go to minimize memory pinned for many idle conns.
+ // Will probably also need to make frame invalidation have a hook too.
+ getReadBuf func(size uint32) []byte
+ readBuf []byte // cache for default getReadBuf
+
+ maxWriteSize uint32 // zero means unlimited; TODO: implement
+
+ w io.Writer
+ wbuf []byte
+
+ // AllowIllegalWrites permits the Framer's Write methods to
+ // write frames that do not conform to the HTTP/2 spec. This
+ // permits using the Framer to test other HTTP/2
+ // implementations' conformance to the spec.
+ // If false, the Write methods will prefer to return an error
+ // rather than comply.
+ AllowIllegalWrites bool
+
+ // AllowIllegalReads permits the Framer's ReadFrame method
+ // to return non-compliant frames or frame orders.
+ // This is for testing and permits using the Framer to test
+ // other HTTP/2 implementations' conformance to the spec.
+ // It is not compatible with ReadMetaHeaders.
+ AllowIllegalReads bool
+
+ // ReadMetaHeaders if non-nil causes ReadFrame to merge
+ // HEADERS and CONTINUATION frames together and return
+ // MetaHeadersFrame instead.
+ ReadMetaHeaders *hpack.Decoder
+
+ // MaxHeaderListSize is the http2 MAX_HEADER_LIST_SIZE.
+ // It's used only if ReadMetaHeaders is set; 0 means a sane default
+ // (currently 16MB)
+ // If the limit is hit, MetaHeadersFrame.Truncated is set true.
+ MaxHeaderListSize uint32
+
+ // TODO: track which type of frame & with which flags was sent
+ // last. Then return an error (unless AllowIllegalWrites) if
+ // we're in the middle of a header block and a
+ // non-Continuation or Continuation on a different stream is
+ // attempted to be written.
+
+ logReads, logWrites bool
+
+ debugFramer *Framer // only use for logging written writes
+ debugFramerBuf *bytes.Buffer
+ debugReadLoggerf func(string, ...interface{})
+ debugWriteLoggerf func(string, ...interface{})
+
+ frameCache *frameCache // nil if frames aren't reused (default)
+}
+
+func (fr *Framer) maxHeaderListSize() uint32 {
+ if fr.MaxHeaderListSize == 0 {
+ return 16 << 20 // sane default, per docs
+ }
+ return fr.MaxHeaderListSize
+}
+
+func (f *Framer) startWrite(ftype FrameType, flags Flags, streamID uint32) {
+ // Write the FrameHeader.
+ f.wbuf = append(f.wbuf[:0],
+ 0, // 3 bytes of length, filled in in endWrite
+ 0,
+ 0,
+ byte(ftype),
+ byte(flags),
+ byte(streamID>>24),
+ byte(streamID>>16),
+ byte(streamID>>8),
+ byte(streamID))
+}
+
+func (f *Framer) endWrite() error {
+ // Now that we know the final size, fill in the FrameHeader in
+ // the space previously reserved for it. Abuse append.
+ length := len(f.wbuf) - frameHeaderLen
+ if length >= (1 << 24) {
+ return ErrFrameTooLarge
+ }
+ _ = append(f.wbuf[:0],
+ byte(length>>16),
+ byte(length>>8),
+ byte(length))
+ if f.logWrites {
+ f.logWrite()
+ }
+
+ n, err := f.w.Write(f.wbuf)
+ if err == nil && n != len(f.wbuf) {
+ err = io.ErrShortWrite
+ }
+ return err
+}
+
+func (f *Framer) logWrite() {
+ if f.debugFramer == nil {
+ f.debugFramerBuf = new(bytes.Buffer)
+ f.debugFramer = NewFramer(nil, f.debugFramerBuf)
+ f.debugFramer.logReads = false // we log it ourselves, saying "wrote" below
+ // Let us read anything, even if we accidentally wrote it
+ // in the wrong order:
+ f.debugFramer.AllowIllegalReads = true
+ }
+ f.debugFramerBuf.Write(f.wbuf)
+ fr, err := f.debugFramer.ReadFrame()
+ if err != nil {
+ f.debugWriteLoggerf("http2: Framer %p: failed to decode just-written frame", f)
+ return
+ }
+ f.debugWriteLoggerf("http2: Framer %p: wrote %v", f, summarizeFrame(fr))
+}
+
+func (f *Framer) writeByte(v byte) { f.wbuf = append(f.wbuf, v) }
+func (f *Framer) writeBytes(v []byte) { f.wbuf = append(f.wbuf, v...) }
+func (f *Framer) writeUint16(v uint16) { f.wbuf = append(f.wbuf, byte(v>>8), byte(v)) }
+func (f *Framer) writeUint32(v uint32) {
+ f.wbuf = append(f.wbuf, byte(v>>24), byte(v>>16), byte(v>>8), byte(v))
+}
+
+const (
+ minMaxFrameSize = 1 << 14
+ maxFrameSize = 1<<24 - 1
+)
+
+// SetReuseFrames allows the Framer to reuse Frames.
+// If called on a Framer, Frames returned by calls to ReadFrame are only
+// valid until the next call to ReadFrame.
+func (fr *Framer) SetReuseFrames() {
+ if fr.frameCache != nil {
+ return
+ }
+ fr.frameCache = &frameCache{}
+}
+
+type frameCache struct {
+ dataFrame DataFrame
+}
+
+func (fc *frameCache) getDataFrame() *DataFrame {
+ if fc == nil {
+ return &DataFrame{}
+ }
+ return &fc.dataFrame
+}
+
+// NewFramer returns a Framer that writes frames to w and reads them from r.
+func NewFramer(w io.Writer, r io.Reader) *Framer {
+ fr := &Framer{
+ w: w,
+ r: r,
+ logReads: logFrameReads,
+ logWrites: logFrameWrites,
+ debugReadLoggerf: log.Printf,
+ debugWriteLoggerf: log.Printf,
+ }
+ fr.getReadBuf = func(size uint32) []byte {
+ if cap(fr.readBuf) >= int(size) {
+ return fr.readBuf[:size]
+ }
+ fr.readBuf = make([]byte, size)
+ return fr.readBuf
+ }
+ fr.SetMaxReadFrameSize(maxFrameSize)
+ return fr
+}
+
+// SetMaxReadFrameSize sets the maximum size of a frame
+// that will be read by a subsequent call to ReadFrame.
+// It is the caller's responsibility to advertise this
+// limit with a SETTINGS frame.
+func (fr *Framer) SetMaxReadFrameSize(v uint32) {
+ if v > maxFrameSize {
+ v = maxFrameSize
+ }
+ fr.maxReadSize = v
+}
+
+// ErrorDetail returns a more detailed error of the last error
+// returned by Framer.ReadFrame. For instance, if ReadFrame
+// returns a StreamError with code PROTOCOL_ERROR, ErrorDetail
+// will say exactly what was invalid. ErrorDetail is not guaranteed
+// to return a non-nil value and like the rest of the http2 package,
+// its return value is not protected by an API compatibility promise.
+// ErrorDetail is reset after the next call to ReadFrame.
+func (fr *Framer) ErrorDetail() error {
+ return fr.errDetail
+}
+
+// ErrFrameTooLarge is returned from Framer.ReadFrame when the peer
+// sends a frame that is larger than declared with SetMaxReadFrameSize.
+var ErrFrameTooLarge = errors.New("http2: frame too large")
+
+// terminalReadFrameError reports whether err is an unrecoverable
+// error from ReadFrame and no other frames should be read.
+func terminalReadFrameError(err error) bool {
+ if _, ok := err.(StreamError); ok {
+ return false
+ }
+ return err != nil
+}
+
+// ReadFrame reads a single frame. The returned Frame is only valid
+// until the next call to ReadFrame.
+//
+// If the frame is larger than previously set with SetMaxReadFrameSize, the
+// returned error is ErrFrameTooLarge. Other errors may be of type
+// ConnectionError, StreamError, or anything else from the underlying
+// reader.
+func (fr *Framer) ReadFrame() (Frame, error) {
+ fr.errDetail = nil
+ if fr.lastFrame != nil {
+ fr.lastFrame.invalidate()
+ }
+ fh, err := readFrameHeader(fr.headerBuf[:], fr.r)
+ if err != nil {
+ return nil, err
+ }
+ if fh.Length > fr.maxReadSize {
+ return nil, ErrFrameTooLarge
+ }
+ payload := fr.getReadBuf(fh.Length)
+ if _, err := io.ReadFull(fr.r, payload); err != nil {
+ return nil, err
+ }
+ f, err := typeFrameParser(fh.Type)(fr.frameCache, fh, payload)
+ if err != nil {
+ if ce, ok := err.(connError); ok {
+ return nil, fr.connError(ce.Code, ce.Reason)
+ }
+ return nil, err
+ }
+ if err := fr.checkFrameOrder(f); err != nil {
+ return nil, err
+ }
+ if fr.logReads {
+ fr.debugReadLoggerf("http2: Framer %p: read %v", fr, summarizeFrame(f))
+ }
+ if fh.Type == FrameHeaders && fr.ReadMetaHeaders != nil {
+ return fr.readMetaFrame(f.(*HeadersFrame))
+ }
+ return f, nil
+}
+
+// connError returns ConnectionError(code) but first
+// stashes away a public reason to the caller can optionally relay it
+// to the peer before hanging up on them. This might help others debug
+// their implementations.
+func (fr *Framer) connError(code ErrCode, reason string) error {
+ fr.errDetail = errors.New(reason)
+ return ConnectionError(code)
+}
+
+// checkFrameOrder reports an error if f is an invalid frame to return
+// next from ReadFrame. Mostly it checks whether HEADERS and
+// CONTINUATION frames are contiguous.
+func (fr *Framer) checkFrameOrder(f Frame) error {
+ last := fr.lastFrame
+ fr.lastFrame = f
+ if fr.AllowIllegalReads {
+ return nil
+ }
+
+ fh := f.Header()
+ if fr.lastHeaderStream != 0 {
+ if fh.Type != FrameContinuation {
+ return fr.connError(ErrCodeProtocol,
+ fmt.Sprintf("got %s for stream %d; expected CONTINUATION following %s for stream %d",
+ fh.Type, fh.StreamID,
+ last.Header().Type, fr.lastHeaderStream))
+ }
+ if fh.StreamID != fr.lastHeaderStream {
+ return fr.connError(ErrCodeProtocol,
+ fmt.Sprintf("got CONTINUATION for stream %d; expected stream %d",
+ fh.StreamID, fr.lastHeaderStream))
+ }
+ } else if fh.Type == FrameContinuation {
+ return fr.connError(ErrCodeProtocol, fmt.Sprintf("unexpected CONTINUATION for stream %d", fh.StreamID))
+ }
+
+ switch fh.Type {
+ case FrameHeaders, FrameContinuation:
+ if fh.Flags.Has(FlagHeadersEndHeaders) {
+ fr.lastHeaderStream = 0
+ } else {
+ fr.lastHeaderStream = fh.StreamID
+ }
+ }
+
+ return nil
+}
+
+// A DataFrame conveys arbitrary, variable-length sequences of octets
+// associated with a stream.
+// See http://http2.github.io/http2-spec/#rfc.section.6.1
+type DataFrame struct {
+ FrameHeader
+ data []byte
+}
+
+func (f *DataFrame) StreamEnded() bool {
+ return f.FrameHeader.Flags.Has(FlagDataEndStream)
+}
+
+// Data returns the frame's data octets, not including any padding
+// size byte or padding suffix bytes.
+// The caller must not retain the returned memory past the next
+// call to ReadFrame.
+func (f *DataFrame) Data() []byte {
+ f.checkValid()
+ return f.data
+}
+
+func parseDataFrame(fc *frameCache, fh FrameHeader, payload []byte) (Frame, error) {
+ if fh.StreamID == 0 {
+ // DATA frames MUST be associated with a stream. If a
+ // DATA frame is received whose stream identifier
+ // field is 0x0, the recipient MUST respond with a
+ // connection error (Section 5.4.1) of type
+ // PROTOCOL_ERROR.
+ return nil, connError{ErrCodeProtocol, "DATA frame with stream ID 0"}
+ }
+ f := fc.getDataFrame()
+ f.FrameHeader = fh
+
+ var padSize byte
+ if fh.Flags.Has(FlagDataPadded) {
+ var err error
+ payload, padSize, err = readByte(payload)
+ if err != nil {
+ return nil, err
+ }
+ }
+ if int(padSize) > len(payload) {
+ // If the length of the padding is greater than the
+ // length of the frame payload, the recipient MUST
+ // treat this as a connection error.
+ // Filed: https://github.com/http2/http2-spec/issues/610
+ return nil, connError{ErrCodeProtocol, "pad size larger than data payload"}
+ }
+ f.data = payload[:len(payload)-int(padSize)]
+ return f, nil
+}
+
+var (
+ errStreamID = errors.New("invalid stream ID")
+ errDepStreamID = errors.New("invalid dependent stream ID")
+ errPadLength = errors.New("pad length too large")
+ errPadBytes = errors.New("padding bytes must all be zeros unless AllowIllegalWrites is enabled")
+)
+
+func validStreamIDOrZero(streamID uint32) bool {
+ return streamID&(1<<31) == 0
+}
+
+func validStreamID(streamID uint32) bool {
+ return streamID != 0 && streamID&(1<<31) == 0
+}
+
+// WriteData writes a DATA frame.
+//
+// It will perform exactly one Write to the underlying Writer.
+// It is the caller's responsibility not to violate the maximum frame size
+// and to not call other Write methods concurrently.
+func (f *Framer) WriteData(streamID uint32, endStream bool, data []byte) error {
+ return f.WriteDataPadded(streamID, endStream, data, nil)
+}
+
+// WriteDataPadded writes a DATA frame with optional padding.
+//
+// If pad is nil, the padding bit is not sent.
+// The length of pad must not exceed 255 bytes.
+// The bytes of pad must all be zero, unless f.AllowIllegalWrites is set.
+//
+// It will perform exactly one Write to the underlying Writer.
+// It is the caller's responsibility not to violate the maximum frame size
+// and to not call other Write methods concurrently.
+func (f *Framer) WriteDataPadded(streamID uint32, endStream bool, data, pad []byte) error {
+ if !validStreamID(streamID) && !f.AllowIllegalWrites {
+ return errStreamID
+ }
+ if len(pad) > 0 {
+ if len(pad) > 255 {
+ return errPadLength
+ }
+ if !f.AllowIllegalWrites {
+ for _, b := range pad {
+ if b != 0 {
+ // "Padding octets MUST be set to zero when sending."
+ return errPadBytes
+ }
+ }
+ }
+ }
+ var flags Flags
+ if endStream {
+ flags |= FlagDataEndStream
+ }
+ if pad != nil {
+ flags |= FlagDataPadded
+ }
+ f.startWrite(FrameData, flags, streamID)
+ if pad != nil {
+ f.wbuf = append(f.wbuf, byte(len(pad)))
+ }
+ f.wbuf = append(f.wbuf, data...)
+ f.wbuf = append(f.wbuf, pad...)
+ return f.endWrite()
+}
+
+// A SettingsFrame conveys configuration parameters that affect how
+// endpoints communicate, such as preferences and constraints on peer
+// behavior.
+//
+// See http://http2.github.io/http2-spec/#SETTINGS
+type SettingsFrame struct {
+ FrameHeader
+ p []byte
+}
+
+func parseSettingsFrame(_ *frameCache, fh FrameHeader, p []byte) (Frame, error) {
+ if fh.Flags.Has(FlagSettingsAck) && fh.Length > 0 {
+ // When this (ACK 0x1) bit is set, the payload of the
+ // SETTINGS frame MUST be empty. Receipt of a
+ // SETTINGS frame with the ACK flag set and a length
+ // field value other than 0 MUST be treated as a
+ // connection error (Section 5.4.1) of type
+ // FRAME_SIZE_ERROR.
+ return nil, ConnectionError(ErrCodeFrameSize)
+ }
+ if fh.StreamID != 0 {
+ // SETTINGS frames always apply to a connection,
+ // never a single stream. The stream identifier for a
+ // SETTINGS frame MUST be zero (0x0). If an endpoint
+ // receives a SETTINGS frame whose stream identifier
+ // field is anything other than 0x0, the endpoint MUST
+ // respond with a connection error (Section 5.4.1) of
+ // type PROTOCOL_ERROR.
+ return nil, ConnectionError(ErrCodeProtocol)
+ }
+ if len(p)%6 != 0 {
+ // Expecting even number of 6 byte settings.
+ return nil, ConnectionError(ErrCodeFrameSize)
+ }
+ f := &SettingsFrame{FrameHeader: fh, p: p}
+ if v, ok := f.Value(SettingInitialWindowSize); ok && v > (1<<31)-1 {
+ // Values above the maximum flow control window size of 2^31 - 1 MUST
+ // be treated as a connection error (Section 5.4.1) of type
+ // FLOW_CONTROL_ERROR.
+ return nil, ConnectionError(ErrCodeFlowControl)
+ }
+ return f, nil
+}
+
+func (f *SettingsFrame) IsAck() bool {
+ return f.FrameHeader.Flags.Has(FlagSettingsAck)
+}
+
+func (f *SettingsFrame) Value(id SettingID) (v uint32, ok bool) {
+ f.checkValid()
+ for i := 0; i < f.NumSettings(); i++ {
+ if s := f.Setting(i); s.ID == id {
+ return s.Val, true
+ }
+ }
+ return 0, false
+}
+
+// Setting returns the setting from the frame at the given 0-based index.
+// The index must be >= 0 and less than f.NumSettings().
+func (f *SettingsFrame) Setting(i int) Setting {
+ buf := f.p
+ return Setting{
+ ID: SettingID(binary.BigEndian.Uint16(buf[i*6 : i*6+2])),
+ Val: binary.BigEndian.Uint32(buf[i*6+2 : i*6+6]),
+ }
+}
+
+func (f *SettingsFrame) NumSettings() int { return len(f.p) / 6 }
+
+// HasDuplicates reports whether f contains any duplicate setting IDs.
+func (f *SettingsFrame) HasDuplicates() bool {
+ num := f.NumSettings()
+ if num == 0 {
+ return false
+ }
+ // If it's small enough (the common case), just do the n^2
+ // thing and avoid a map allocation.
+ if num < 10 {
+ for i := 0; i < num; i++ {
+ idi := f.Setting(i).ID
+ for j := i + 1; j < num; j++ {
+ idj := f.Setting(j).ID
+ if idi == idj {
+ return true
+ }
+ }
+ }
+ return false
+ }
+ seen := map[SettingID]bool{}
+ for i := 0; i < num; i++ {
+ id := f.Setting(i).ID
+ if seen[id] {
+ return true
+ }
+ seen[id] = true
+ }
+ return false
+}
+
+// ForeachSetting runs fn for each setting.
+// It stops and returns the first error.
+func (f *SettingsFrame) ForeachSetting(fn func(Setting) error) error {
+ f.checkValid()
+ for i := 0; i < f.NumSettings(); i++ {
+ if err := fn(f.Setting(i)); err != nil {
+ return err
+ }
+ }
+ return nil
+}
+
+// WriteSettings writes a SETTINGS frame with zero or more settings
+// specified and the ACK bit not set.
+//
+// It will perform exactly one Write to the underlying Writer.
+// It is the caller's responsibility to not call other Write methods concurrently.
+func (f *Framer) WriteSettings(settings ...Setting) error {
+ f.startWrite(FrameSettings, 0, 0)
+ for _, s := range settings {
+ f.writeUint16(uint16(s.ID))
+ f.writeUint32(s.Val)
+ }
+ return f.endWrite()
+}
+
+// WriteSettingsAck writes an empty SETTINGS frame with the ACK bit set.
+//
+// It will perform exactly one Write to the underlying Writer.
+// It is the caller's responsibility to not call other Write methods concurrently.
+func (f *Framer) WriteSettingsAck() error {
+ f.startWrite(FrameSettings, FlagSettingsAck, 0)
+ return f.endWrite()
+}
+
+// A PingFrame is a mechanism for measuring a minimal round trip time
+// from the sender, as well as determining whether an idle connection
+// is still functional.
+// See http://http2.github.io/http2-spec/#rfc.section.6.7
+type PingFrame struct {
+ FrameHeader
+ Data [8]byte
+}
+
+func (f *PingFrame) IsAck() bool { return f.Flags.Has(FlagPingAck) }
+
+func parsePingFrame(_ *frameCache, fh FrameHeader, payload []byte) (Frame, error) {
+ if len(payload) != 8 {
+ return nil, ConnectionError(ErrCodeFrameSize)
+ }
+ if fh.StreamID != 0 {
+ return nil, ConnectionError(ErrCodeProtocol)
+ }
+ f := &PingFrame{FrameHeader: fh}
+ copy(f.Data[:], payload)
+ return f, nil
+}
+
+func (f *Framer) WritePing(ack bool, data [8]byte) error {
+ var flags Flags
+ if ack {
+ flags = FlagPingAck
+ }
+ f.startWrite(FramePing, flags, 0)
+ f.writeBytes(data[:])
+ return f.endWrite()
+}
+
+// A GoAwayFrame informs the remote peer to stop creating streams on this connection.
+// See http://http2.github.io/http2-spec/#rfc.section.6.8
+type GoAwayFrame struct {
+ FrameHeader
+ LastStreamID uint32
+ ErrCode ErrCode
+ debugData []byte
+}
+
+// DebugData returns any debug data in the GOAWAY frame. Its contents
+// are not defined.
+// The caller must not retain the returned memory past the next
+// call to ReadFrame.
+func (f *GoAwayFrame) DebugData() []byte {
+ f.checkValid()
+ return f.debugData
+}
+
+func parseGoAwayFrame(_ *frameCache, fh FrameHeader, p []byte) (Frame, error) {
+ if fh.StreamID != 0 {
+ return nil, ConnectionError(ErrCodeProtocol)
+ }
+ if len(p) < 8 {
+ return nil, ConnectionError(ErrCodeFrameSize)
+ }
+ return &GoAwayFrame{
+ FrameHeader: fh,
+ LastStreamID: binary.BigEndian.Uint32(p[:4]) & (1<<31 - 1),
+ ErrCode: ErrCode(binary.BigEndian.Uint32(p[4:8])),
+ debugData: p[8:],
+ }, nil
+}
+
+func (f *Framer) WriteGoAway(maxStreamID uint32, code ErrCode, debugData []byte) error {
+ f.startWrite(FrameGoAway, 0, 0)
+ f.writeUint32(maxStreamID & (1<<31 - 1))
+ f.writeUint32(uint32(code))
+ f.writeBytes(debugData)
+ return f.endWrite()
+}
+
+// An UnknownFrame is the frame type returned when the frame type is unknown
+// or no specific frame type parser exists.
+type UnknownFrame struct {
+ FrameHeader
+ p []byte
+}
+
+// Payload returns the frame's payload (after the header). It is not
+// valid to call this method after a subsequent call to
+// Framer.ReadFrame, nor is it valid to retain the returned slice.
+// The memory is owned by the Framer and is invalidated when the next
+// frame is read.
+func (f *UnknownFrame) Payload() []byte {
+ f.checkValid()
+ return f.p
+}
+
+func parseUnknownFrame(_ *frameCache, fh FrameHeader, p []byte) (Frame, error) {
+ return &UnknownFrame{fh, p}, nil
+}
+
+// A WindowUpdateFrame is used to implement flow control.
+// See http://http2.github.io/http2-spec/#rfc.section.6.9
+type WindowUpdateFrame struct {
+ FrameHeader
+ Increment uint32 // never read with high bit set
+}
+
+func parseWindowUpdateFrame(_ *frameCache, fh FrameHeader, p []byte) (Frame, error) {
+ if len(p) != 4 {
+ return nil, ConnectionError(ErrCodeFrameSize)
+ }
+ inc := binary.BigEndian.Uint32(p[:4]) & 0x7fffffff // mask off high reserved bit
+ if inc == 0 {
+ // A receiver MUST treat the receipt of a
+ // WINDOW_UPDATE frame with an flow control window
+ // increment of 0 as a stream error (Section 5.4.2) of
+ // type PROTOCOL_ERROR; errors on the connection flow
+ // control window MUST be treated as a connection
+ // error (Section 5.4.1).
+ if fh.StreamID == 0 {
+ return nil, ConnectionError(ErrCodeProtocol)
+ }
+ return nil, streamError(fh.StreamID, ErrCodeProtocol)
+ }
+ return &WindowUpdateFrame{
+ FrameHeader: fh,
+ Increment: inc,
+ }, nil
+}
+
+// WriteWindowUpdate writes a WINDOW_UPDATE frame.
+// The increment value must be between 1 and 2,147,483,647, inclusive.
+// If the Stream ID is zero, the window update applies to the
+// connection as a whole.
+func (f *Framer) WriteWindowUpdate(streamID, incr uint32) error {
+ // "The legal range for the increment to the flow control window is 1 to 2^31-1 (2,147,483,647) octets."
+ if (incr < 1 || incr > 2147483647) && !f.AllowIllegalWrites {
+ return errors.New("illegal window increment value")
+ }
+ f.startWrite(FrameWindowUpdate, 0, streamID)
+ f.writeUint32(incr)
+ return f.endWrite()
+}
+
+// A HeadersFrame is used to open a stream and additionally carries a
+// header block fragment.
+type HeadersFrame struct {
+ FrameHeader
+
+ // Priority is set if FlagHeadersPriority is set in the FrameHeader.
+ Priority PriorityParam
+
+ headerFragBuf []byte // not owned
+}
+
+func (f *HeadersFrame) HeaderBlockFragment() []byte {
+ f.checkValid()
+ return f.headerFragBuf
+}
+
+func (f *HeadersFrame) HeadersEnded() bool {
+ return f.FrameHeader.Flags.Has(FlagHeadersEndHeaders)
+}
+
+func (f *HeadersFrame) StreamEnded() bool {
+ return f.FrameHeader.Flags.Has(FlagHeadersEndStream)
+}
+
+func (f *HeadersFrame) HasPriority() bool {
+ return f.FrameHeader.Flags.Has(FlagHeadersPriority)
+}
+
+func parseHeadersFrame(_ *frameCache, fh FrameHeader, p []byte) (_ Frame, err error) {
+ hf := &HeadersFrame{
+ FrameHeader: fh,
+ }
+ if fh.StreamID == 0 {
+ // HEADERS frames MUST be associated with a stream. If a HEADERS frame
+ // is received whose stream identifier field is 0x0, the recipient MUST
+ // respond with a connection error (Section 5.4.1) of type
+ // PROTOCOL_ERROR.
+ return nil, connError{ErrCodeProtocol, "HEADERS frame with stream ID 0"}
+ }
+ var padLength uint8
+ if fh.Flags.Has(FlagHeadersPadded) {
+ if p, padLength, err = readByte(p); err != nil {
+ return
+ }
+ }
+ if fh.Flags.Has(FlagHeadersPriority) {
+ var v uint32
+ p, v, err = readUint32(p)
+ if err != nil {
+ return nil, err
+ }
+ hf.Priority.StreamDep = v & 0x7fffffff
+ hf.Priority.Exclusive = (v != hf.Priority.StreamDep) // high bit was set
+ p, hf.Priority.Weight, err = readByte(p)
+ if err != nil {
+ return nil, err
+ }
+ }
+ if len(p)-int(padLength) <= 0 {
+ return nil, streamError(fh.StreamID, ErrCodeProtocol)
+ }
+ hf.headerFragBuf = p[:len(p)-int(padLength)]
+ return hf, nil
+}
+
+// HeadersFrameParam are the parameters for writing a HEADERS frame.
+type HeadersFrameParam struct {
+ // StreamID is the required Stream ID to initiate.
+ StreamID uint32
+ // BlockFragment is part (or all) of a Header Block.
+ BlockFragment []byte
+
+ // EndStream indicates that the header block is the last that
+ // the endpoint will send for the identified stream. Setting
+ // this flag causes the stream to enter one of "half closed"
+ // states.
+ EndStream bool
+
+ // EndHeaders indicates that this frame contains an entire
+ // header block and is not followed by any
+ // CONTINUATION frames.
+ EndHeaders bool
+
+ // PadLength is the optional number of bytes of zeros to add
+ // to this frame.
+ PadLength uint8
+
+ // Priority, if non-zero, includes stream priority information
+ // in the HEADER frame.
+ Priority PriorityParam
+}
+
+// WriteHeaders writes a single HEADERS frame.
+//
+// This is a low-level header writing method. Encoding headers and
+// splitting them into any necessary CONTINUATION frames is handled
+// elsewhere.
+//
+// It will perform exactly one Write to the underlying Writer.
+// It is the caller's responsibility to not call other Write methods concurrently.
+func (f *Framer) WriteHeaders(p HeadersFrameParam) error {
+ if !validStreamID(p.StreamID) && !f.AllowIllegalWrites {
+ return errStreamID
+ }
+ var flags Flags
+ if p.PadLength != 0 {
+ flags |= FlagHeadersPadded
+ }
+ if p.EndStream {
+ flags |= FlagHeadersEndStream
+ }
+ if p.EndHeaders {
+ flags |= FlagHeadersEndHeaders
+ }
+ if !p.Priority.IsZero() {
+ flags |= FlagHeadersPriority
+ }
+ f.startWrite(FrameHeaders, flags, p.StreamID)
+ if p.PadLength != 0 {
+ f.writeByte(p.PadLength)
+ }
+ if !p.Priority.IsZero() {
+ v := p.Priority.StreamDep
+ if !validStreamIDOrZero(v) && !f.AllowIllegalWrites {
+ return errDepStreamID
+ }
+ if p.Priority.Exclusive {
+ v |= 1 << 31
+ }
+ f.writeUint32(v)
+ f.writeByte(p.Priority.Weight)
+ }
+ f.wbuf = append(f.wbuf, p.BlockFragment...)
+ f.wbuf = append(f.wbuf, padZeros[:p.PadLength]...)
+ return f.endWrite()
+}
+
+// A PriorityFrame specifies the sender-advised priority of a stream.
+// See http://http2.github.io/http2-spec/#rfc.section.6.3
+type PriorityFrame struct {
+ FrameHeader
+ PriorityParam
+}
+
+// PriorityParam are the stream prioritzation parameters.
+type PriorityParam struct {
+ // StreamDep is a 31-bit stream identifier for the
+ // stream that this stream depends on. Zero means no
+ // dependency.
+ StreamDep uint32
+
+ // Exclusive is whether the dependency is exclusive.
+ Exclusive bool
+
+ // Weight is the stream's zero-indexed weight. It should be
+ // set together with StreamDep, or neither should be set. Per
+ // the spec, "Add one to the value to obtain a weight between
+ // 1 and 256."
+ Weight uint8
+}
+
+func (p PriorityParam) IsZero() bool {
+ return p == PriorityParam{}
+}
+
+func parsePriorityFrame(_ *frameCache, fh FrameHeader, payload []byte) (Frame, error) {
+ if fh.StreamID == 0 {
+ return nil, connError{ErrCodeProtocol, "PRIORITY frame with stream ID 0"}
+ }
+ if len(payload) != 5 {
+ return nil, connError{ErrCodeFrameSize, fmt.Sprintf("PRIORITY frame payload size was %d; want 5", len(payload))}
+ }
+ v := binary.BigEndian.Uint32(payload[:4])
+ streamID := v & 0x7fffffff // mask off high bit
+ return &PriorityFrame{
+ FrameHeader: fh,
+ PriorityParam: PriorityParam{
+ Weight: payload[4],
+ StreamDep: streamID,
+ Exclusive: streamID != v, // was high bit set?
+ },
+ }, nil
+}
+
+// WritePriority writes a PRIORITY frame.
+//
+// It will perform exactly one Write to the underlying Writer.
+// It is the caller's responsibility to not call other Write methods concurrently.
+func (f *Framer) WritePriority(streamID uint32, p PriorityParam) error {
+ if !validStreamID(streamID) && !f.AllowIllegalWrites {
+ return errStreamID
+ }
+ if !validStreamIDOrZero(p.StreamDep) {
+ return errDepStreamID
+ }
+ f.startWrite(FramePriority, 0, streamID)
+ v := p.StreamDep
+ if p.Exclusive {
+ v |= 1 << 31
+ }
+ f.writeUint32(v)
+ f.writeByte(p.Weight)
+ return f.endWrite()
+}
+
+// A RSTStreamFrame allows for abnormal termination of a stream.
+// See http://http2.github.io/http2-spec/#rfc.section.6.4
+type RSTStreamFrame struct {
+ FrameHeader
+ ErrCode ErrCode
+}
+
+func parseRSTStreamFrame(_ *frameCache, fh FrameHeader, p []byte) (Frame, error) {
+ if len(p) != 4 {
+ return nil, ConnectionError(ErrCodeFrameSize)
+ }
+ if fh.StreamID == 0 {
+ return nil, ConnectionError(ErrCodeProtocol)
+ }
+ return &RSTStreamFrame{fh, ErrCode(binary.BigEndian.Uint32(p[:4]))}, nil
+}
+
+// WriteRSTStream writes a RST_STREAM frame.
+//
+// It will perform exactly one Write to the underlying Writer.
+// It is the caller's responsibility to not call other Write methods concurrently.
+func (f *Framer) WriteRSTStream(streamID uint32, code ErrCode) error {
+ if !validStreamID(streamID) && !f.AllowIllegalWrites {
+ return errStreamID
+ }
+ f.startWrite(FrameRSTStream, 0, streamID)
+ f.writeUint32(uint32(code))
+ return f.endWrite()
+}
+
+// A ContinuationFrame is used to continue a sequence of header block fragments.
+// See http://http2.github.io/http2-spec/#rfc.section.6.10
+type ContinuationFrame struct {
+ FrameHeader
+ headerFragBuf []byte
+}
+
+func parseContinuationFrame(_ *frameCache, fh FrameHeader, p []byte) (Frame, error) {
+ if fh.StreamID == 0 {
+ return nil, connError{ErrCodeProtocol, "CONTINUATION frame with stream ID 0"}
+ }
+ return &ContinuationFrame{fh, p}, nil
+}
+
+func (f *ContinuationFrame) HeaderBlockFragment() []byte {
+ f.checkValid()
+ return f.headerFragBuf
+}
+
+func (f *ContinuationFrame) HeadersEnded() bool {
+ return f.FrameHeader.Flags.Has(FlagContinuationEndHeaders)
+}
+
+// WriteContinuation writes a CONTINUATION frame.
+//
+// It will perform exactly one Write to the underlying Writer.
+// It is the caller's responsibility to not call other Write methods concurrently.
+func (f *Framer) WriteContinuation(streamID uint32, endHeaders bool, headerBlockFragment []byte) error {
+ if !validStreamID(streamID) && !f.AllowIllegalWrites {
+ return errStreamID
+ }
+ var flags Flags
+ if endHeaders {
+ flags |= FlagContinuationEndHeaders
+ }
+ f.startWrite(FrameContinuation, flags, streamID)
+ f.wbuf = append(f.wbuf, headerBlockFragment...)
+ return f.endWrite()
+}
+
+// A PushPromiseFrame is used to initiate a server stream.
+// See http://http2.github.io/http2-spec/#rfc.section.6.6
+type PushPromiseFrame struct {
+ FrameHeader
+ PromiseID uint32
+ headerFragBuf []byte // not owned
+}
+
+func (f *PushPromiseFrame) HeaderBlockFragment() []byte {
+ f.checkValid()
+ return f.headerFragBuf
+}
+
+func (f *PushPromiseFrame) HeadersEnded() bool {
+ return f.FrameHeader.Flags.Has(FlagPushPromiseEndHeaders)
+}
+
+func parsePushPromise(_ *frameCache, fh FrameHeader, p []byte) (_ Frame, err error) {
+ pp := &PushPromiseFrame{
+ FrameHeader: fh,
+ }
+ if pp.StreamID == 0 {
+ // PUSH_PROMISE frames MUST be associated with an existing,
+ // peer-initiated stream. The stream identifier of a
+ // PUSH_PROMISE frame indicates the stream it is associated
+ // with. If the stream identifier field specifies the value
+ // 0x0, a recipient MUST respond with a connection error
+ // (Section 5.4.1) of type PROTOCOL_ERROR.
+ return nil, ConnectionError(ErrCodeProtocol)
+ }
+ // The PUSH_PROMISE frame includes optional padding.
+ // Padding fields and flags are identical to those defined for DATA frames
+ var padLength uint8
+ if fh.Flags.Has(FlagPushPromisePadded) {
+ if p, padLength, err = readByte(p); err != nil {
+ return
+ }
+ }
+
+ p, pp.PromiseID, err = readUint32(p)
+ if err != nil {
+ return
+ }
+ pp.PromiseID = pp.PromiseID & (1<<31 - 1)
+
+ if int(padLength) > len(p) {
+ // like the DATA frame, error out if padding is longer than the body.
+ return nil, ConnectionError(ErrCodeProtocol)
+ }
+ pp.headerFragBuf = p[:len(p)-int(padLength)]
+ return pp, nil
+}
+
+// PushPromiseParam are the parameters for writing a PUSH_PROMISE frame.
+type PushPromiseParam struct {
+ // StreamID is the required Stream ID to initiate.
+ StreamID uint32
+
+ // PromiseID is the required Stream ID which this
+ // Push Promises
+ PromiseID uint32
+
+ // BlockFragment is part (or all) of a Header Block.
+ BlockFragment []byte
+
+ // EndHeaders indicates that this frame contains an entire
+ // header block and is not followed by any
+ // CONTINUATION frames.
+ EndHeaders bool
+
+ // PadLength is the optional number of bytes of zeros to add
+ // to this frame.
+ PadLength uint8
+}
+
+// WritePushPromise writes a single PushPromise Frame.
+//
+// As with Header Frames, This is the low level call for writing
+// individual frames. Continuation frames are handled elsewhere.
+//
+// It will perform exactly one Write to the underlying Writer.
+// It is the caller's responsibility to not call other Write methods concurrently.
+func (f *Framer) WritePushPromise(p PushPromiseParam) error {
+ if !validStreamID(p.StreamID) && !f.AllowIllegalWrites {
+ return errStreamID
+ }
+ var flags Flags
+ if p.PadLength != 0 {
+ flags |= FlagPushPromisePadded
+ }
+ if p.EndHeaders {
+ flags |= FlagPushPromiseEndHeaders
+ }
+ f.startWrite(FramePushPromise, flags, p.StreamID)
+ if p.PadLength != 0 {
+ f.writeByte(p.PadLength)
+ }
+ if !validStreamID(p.PromiseID) && !f.AllowIllegalWrites {
+ return errStreamID
+ }
+ f.writeUint32(p.PromiseID)
+ f.wbuf = append(f.wbuf, p.BlockFragment...)
+ f.wbuf = append(f.wbuf, padZeros[:p.PadLength]...)
+ return f.endWrite()
+}
+
+// WriteRawFrame writes a raw frame. This can be used to write
+// extension frames unknown to this package.
+func (f *Framer) WriteRawFrame(t FrameType, flags Flags, streamID uint32, payload []byte) error {
+ f.startWrite(t, flags, streamID)
+ f.writeBytes(payload)
+ return f.endWrite()
+}
+
+func readByte(p []byte) (remain []byte, b byte, err error) {
+ if len(p) == 0 {
+ return nil, 0, io.ErrUnexpectedEOF
+ }
+ return p[1:], p[0], nil
+}
+
+func readUint32(p []byte) (remain []byte, v uint32, err error) {
+ if len(p) < 4 {
+ return nil, 0, io.ErrUnexpectedEOF
+ }
+ return p[4:], binary.BigEndian.Uint32(p[:4]), nil
+}
+
+type streamEnder interface {
+ StreamEnded() bool
+}
+
+type headersEnder interface {
+ HeadersEnded() bool
+}
+
+type headersOrContinuation interface {
+ headersEnder
+ HeaderBlockFragment() []byte
+}
+
+// A MetaHeadersFrame is the representation of one HEADERS frame and
+// zero or more contiguous CONTINUATION frames and the decoding of
+// their HPACK-encoded contents.
+//
+// This type of frame does not appear on the wire and is only returned
+// by the Framer when Framer.ReadMetaHeaders is set.
+type MetaHeadersFrame struct {
+ *HeadersFrame
+
+ // Fields are the fields contained in the HEADERS and
+ // CONTINUATION frames. The underlying slice is owned by the
+ // Framer and must not be retained after the next call to
+ // ReadFrame.
+ //
+ // Fields are guaranteed to be in the correct http2 order and
+ // not have unknown pseudo header fields or invalid header
+ // field names or values. Required pseudo header fields may be
+ // missing, however. Use the MetaHeadersFrame.Pseudo accessor
+ // method access pseudo headers.
+ Fields []hpack.HeaderField
+
+ // Truncated is whether the max header list size limit was hit
+ // and Fields is incomplete. The hpack decoder state is still
+ // valid, however.
+ Truncated bool
+}
+
+// PseudoValue returns the given pseudo header field's value.
+// The provided pseudo field should not contain the leading colon.
+func (mh *MetaHeadersFrame) PseudoValue(pseudo string) string {
+ for _, hf := range mh.Fields {
+ if !hf.IsPseudo() {
+ return ""
+ }
+ if hf.Name[1:] == pseudo {
+ return hf.Value
+ }
+ }
+ return ""
+}
+
+// RegularFields returns the regular (non-pseudo) header fields of mh.
+// The caller does not own the returned slice.
+func (mh *MetaHeadersFrame) RegularFields() []hpack.HeaderField {
+ for i, hf := range mh.Fields {
+ if !hf.IsPseudo() {
+ return mh.Fields[i:]
+ }
+ }
+ return nil
+}
+
+// PseudoFields returns the pseudo header fields of mh.
+// The caller does not own the returned slice.
+func (mh *MetaHeadersFrame) PseudoFields() []hpack.HeaderField {
+ for i, hf := range mh.Fields {
+ if !hf.IsPseudo() {
+ return mh.Fields[:i]
+ }
+ }
+ return mh.Fields
+}
+
+func (mh *MetaHeadersFrame) checkPseudos() error {
+ var isRequest, isResponse bool
+ pf := mh.PseudoFields()
+ for i, hf := range pf {
+ switch hf.Name {
+ case ":method", ":path", ":scheme", ":authority":
+ isRequest = true
+ case ":status":
+ isResponse = true
+ default:
+ return pseudoHeaderError(hf.Name)
+ }
+ // Check for duplicates.
+ // This would be a bad algorithm, but N is 4.
+ // And this doesn't allocate.
+ for _, hf2 := range pf[:i] {
+ if hf.Name == hf2.Name {
+ return duplicatePseudoHeaderError(hf.Name)
+ }
+ }
+ }
+ if isRequest && isResponse {
+ return errMixPseudoHeaderTypes
+ }
+ return nil
+}
+
+func (fr *Framer) maxHeaderStringLen() int {
+ v := fr.maxHeaderListSize()
+ if uint32(int(v)) == v {
+ return int(v)
+ }
+ // They had a crazy big number for MaxHeaderBytes anyway,
+ // so give them unlimited header lengths:
+ return 0
+}
+
+// readMetaFrame returns 0 or more CONTINUATION frames from fr and
+// merge them 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 && fr.logReads {
+ fr.debugReadLoggerf("http2: decoded hpack field %+v", hf)
+ }
+ if !httpguts.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
+}
+
+func summarizeFrame(f Frame) string {
+ var buf bytes.Buffer
+ f.Header().writeDebug(&buf)
+ switch f := f.(type) {
+ case *SettingsFrame:
+ n := 0
+ f.ForeachSetting(func(s Setting) error {
+ n++
+ if n == 1 {
+ buf.WriteString(", settings:")
+ }
+ fmt.Fprintf(&buf, " %v=%v,", s.ID, s.Val)
+ return nil
+ })
+ if n > 0 {
+ buf.Truncate(buf.Len() - 1) // remove trailing comma
+ }
+ case *DataFrame:
+ data := f.Data()
+ const max = 256
+ if len(data) > max {
+ data = data[:max]
+ }
+ fmt.Fprintf(&buf, " data=%q", data)
+ if len(f.Data()) > max {
+ fmt.Fprintf(&buf, " (%d bytes omitted)", len(f.Data())-max)
+ }
+ case *WindowUpdateFrame:
+ if f.StreamID == 0 {
+ buf.WriteString(" (conn)")
+ }
+ fmt.Fprintf(&buf, " incr=%v", f.Increment)
+ case *PingFrame:
+ fmt.Fprintf(&buf, " ping=%q", f.Data[:])
+ case *GoAwayFrame:
+ fmt.Fprintf(&buf, " LastStreamID=%v ErrCode=%v Debug=%q",
+ f.LastStreamID, f.ErrCode, f.debugData)
+ case *RSTStreamFrame:
+ fmt.Fprintf(&buf, " ErrCode=%v", f.ErrCode)
+ }
+ return buf.String()
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-22 23:52:08 +0000