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h2_bundle.go
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h2_bundle.go
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// Code generated by golang.org/x/tools/cmd/bundle.
//go:generate bundle -o h2_bundle.go -prefix http2 golang.org/x/net/http2
// Package http2 implements the HTTP/2 protocol.
//
// This package is low-level and intended to be used directly by very
// few people. Most users will use it indirectly through the automatic
// use by the net/http package (from Go 1.6 and later).
// For use in earlier Go versions see ConfigureServer. (Transport support
// requires Go 1.6 or later)
//
// See https://http2.github.io/ for more information on HTTP/2.
//
// See https://http2.golang.org/ for a test server running this code.
//
package http
import (
"bufio"
"bytes"
"compress/gzip"
"context"
"crypto/tls"
"encoding/binary"
"errors"
"fmt"
"io"
"io/ioutil"
"log"
"net"
"net/http/httptrace"
"net/textproto"
"net/url"
"os"
"reflect"
"runtime"
"sort"
"strconv"
"strings"
"sync"
"time"
"golang.org/x/net/http2/hpack"
"golang.org/x/net/lex/httplex"
)
// ClientConnPool manages a pool of HTTP/2 client connections.
type http2ClientConnPool interface {
GetClientConn(req *Request, addr string) (*http2ClientConn, error)
MarkDead(*http2ClientConn)
}
// clientConnPoolIdleCloser is the interface implemented by ClientConnPool
// implementations which can close their idle connections.
type http2clientConnPoolIdleCloser interface {
http2ClientConnPool
closeIdleConnections()
}
var (
_ http2clientConnPoolIdleCloser = (*http2clientConnPool)(nil)
_ http2clientConnPoolIdleCloser = http2noDialClientConnPool{}
)
// TODO: use singleflight for dialing and addConnCalls?
type http2clientConnPool struct {
t *http2Transport
mu sync.Mutex // TODO: maybe switch to RWMutex
// TODO: add support for sharing conns based on cert names
// (e.g. share conn for googleapis.com and appspot.com)
conns map[string][]*http2ClientConn // key is host:port
dialing map[string]*http2dialCall // currently in-flight dials
keys map[*http2ClientConn][]string
addConnCalls map[string]*http2addConnCall // in-flight addConnIfNeede calls
}
func (p *http2clientConnPool) GetClientConn(req *Request, addr string) (*http2ClientConn, error) {
return p.getClientConn(req, addr, http2dialOnMiss)
}
const (
http2dialOnMiss = true
http2noDialOnMiss = false
)
func (p *http2clientConnPool) getClientConn(_ *Request, addr string, dialOnMiss bool) (*http2ClientConn, error) {
p.mu.Lock()
for _, cc := range p.conns[addr] {
if cc.CanTakeNewRequest() {
p.mu.Unlock()
return cc, nil
}
}
if !dialOnMiss {
p.mu.Unlock()
return nil, http2ErrNoCachedConn
}
call := p.getStartDialLocked(addr)
p.mu.Unlock()
<-call.done
return call.res, call.err
}
// dialCall is an in-flight Transport dial call to a host.
type http2dialCall struct {
p *http2clientConnPool
done chan struct{} // closed when done
res *http2ClientConn // valid after done is closed
err error // valid after done is closed
}
// requires p.mu is held.
func (p *http2clientConnPool) getStartDialLocked(addr string) *http2dialCall {
if call, ok := p.dialing[addr]; ok {
return call
}
call := &http2dialCall{p: p, done: make(chan struct{})}
if p.dialing == nil {
p.dialing = make(map[string]*http2dialCall)
}
p.dialing[addr] = call
go call.dial(addr)
return call
}
// run in its own goroutine.
func (c *http2dialCall) dial(addr string) {
c.res, c.err = c.p.t.dialClientConn(addr)
close(c.done)
c.p.mu.Lock()
delete(c.p.dialing, addr)
if c.err == nil {
c.p.addConnLocked(addr, c.res)
}
c.p.mu.Unlock()
}
// addConnIfNeeded makes a NewClientConn out of c if a connection for key doesn't
// already exist. It coalesces concurrent calls with the same key.
// This is used by the http1 Transport code when it creates a new connection. Because
// the http1 Transport doesn't de-dup TCP dials to outbound hosts (because it doesn't know
// the protocol), it can get into a situation where it has multiple TLS connections.
// This code decides which ones live or die.
// The return value used is whether c was used.
// c is never closed.
func (p *http2clientConnPool) addConnIfNeeded(key string, t *http2Transport, c *tls.Conn) (used bool, err error) {
p.mu.Lock()
for _, cc := range p.conns[key] {
if cc.CanTakeNewRequest() {
p.mu.Unlock()
return false, nil
}
}
call, dup := p.addConnCalls[key]
if !dup {
if p.addConnCalls == nil {
p.addConnCalls = make(map[string]*http2addConnCall)
}
call = &http2addConnCall{
p: p,
done: make(chan struct{}),
}
p.addConnCalls[key] = call
go call.run(t, key, c)
}
p.mu.Unlock()
<-call.done
if call.err != nil {
return false, call.err
}
return !dup, nil
}
type http2addConnCall struct {
p *http2clientConnPool
done chan struct{} // closed when done
err error
}
func (c *http2addConnCall) run(t *http2Transport, key string, tc *tls.Conn) {
cc, err := t.NewClientConn(tc)
p := c.p
p.mu.Lock()
if err != nil {
c.err = err
} else {
p.addConnLocked(key, cc)
}
delete(p.addConnCalls, key)
p.mu.Unlock()
close(c.done)
}
func (p *http2clientConnPool) addConn(key string, cc *http2ClientConn) {
p.mu.Lock()
p.addConnLocked(key, cc)
p.mu.Unlock()
}
// p.mu must be held
func (p *http2clientConnPool) addConnLocked(key string, cc *http2ClientConn) {
for _, v := range p.conns[key] {
if v == cc {
return
}
}
if p.conns == nil {
p.conns = make(map[string][]*http2ClientConn)
}
if p.keys == nil {
p.keys = make(map[*http2ClientConn][]string)
}
p.conns[key] = append(p.conns[key], cc)
p.keys[cc] = append(p.keys[cc], key)
}
func (p *http2clientConnPool) MarkDead(cc *http2ClientConn) {
p.mu.Lock()
defer p.mu.Unlock()
for _, key := range p.keys[cc] {
vv, ok := p.conns[key]
if !ok {
continue
}
newList := http2filterOutClientConn(vv, cc)
if len(newList) > 0 {
p.conns[key] = newList
} else {
delete(p.conns, key)
}
}
delete(p.keys, cc)
}
func (p *http2clientConnPool) closeIdleConnections() {
p.mu.Lock()
defer p.mu.Unlock()
for _, vv := range p.conns {
for _, cc := range vv {
cc.closeIfIdle()
}
}
}
func http2filterOutClientConn(in []*http2ClientConn, exclude *http2ClientConn) []*http2ClientConn {
out := in[:0]
for _, v := range in {
if v != exclude {
out = append(out, v)
}
}
if len(in) != len(out) {
in[len(in)-1] = nil
}
return out
}
// noDialClientConnPool is an implementation of http2.ClientConnPool
// which never dials. We let the HTTP/1.1 client dial and use its TLS
// connection instead.
type http2noDialClientConnPool struct{ *http2clientConnPool }
func (p http2noDialClientConnPool) GetClientConn(req *Request, addr string) (*http2ClientConn, error) {
return p.getClientConn(req, addr, http2noDialOnMiss)
}
func http2configureTransport(t1 *Transport) (*http2Transport, error) {
connPool := new(http2clientConnPool)
t2 := &http2Transport{
ConnPool: http2noDialClientConnPool{connPool},
t1: t1,
}
connPool.t = t2
if err := http2registerHTTPSProtocol(t1, http2noDialH2RoundTripper{t2}); err != nil {
return nil, err
}
if t1.TLSClientConfig == nil {
t1.TLSClientConfig = new(tls.Config)
}
if !http2strSliceContains(t1.TLSClientConfig.NextProtos, "h2") {
t1.TLSClientConfig.NextProtos = append([]string{"h2"}, t1.TLSClientConfig.NextProtos...)
}
if !http2strSliceContains(t1.TLSClientConfig.NextProtos, "http/1.1") {
t1.TLSClientConfig.NextProtos = append(t1.TLSClientConfig.NextProtos, "http/1.1")
}
upgradeFn := func(authority string, c *tls.Conn) RoundTripper {
addr := http2authorityAddr("https", authority)
if used, err := connPool.addConnIfNeeded(addr, t2, c); err != nil {
go c.Close()
return http2erringRoundTripper{err}
} else if !used {
go c.Close()
}
return t2
}
if m := t1.TLSNextProto; len(m) == 0 {
t1.TLSNextProto = map[string]func(string, *tls.Conn) RoundTripper{
"h2": upgradeFn,
}
} else {
m["h2"] = upgradeFn
}
return t2, nil
}
// registerHTTPSProtocol calls Transport.RegisterProtocol but
// convering panics into errors.
func http2registerHTTPSProtocol(t *Transport, rt RoundTripper) (err error) {
defer func() {
if e := recover(); e != nil {
err = fmt.Errorf("%v", e)
}
}()
t.RegisterProtocol("https", rt)
return nil
}
// noDialH2RoundTripper is a RoundTripper which only tries to complete the request
// if there's already has a cached connection to the host.
type http2noDialH2RoundTripper struct{ t *http2Transport }
func (rt http2noDialH2RoundTripper) RoundTrip(req *Request) (*Response, error) {
res, err := rt.t.RoundTrip(req)
if err == http2ErrNoCachedConn {
return nil, ErrSkipAltProtocol
}
return res, err
}
// An ErrCode is an unsigned 32-bit error code as defined in the HTTP/2 spec.
type http2ErrCode uint32
const (
http2ErrCodeNo http2ErrCode = 0x0
http2ErrCodeProtocol http2ErrCode = 0x1
http2ErrCodeInternal http2ErrCode = 0x2
http2ErrCodeFlowControl http2ErrCode = 0x3
http2ErrCodeSettingsTimeout http2ErrCode = 0x4
http2ErrCodeStreamClosed http2ErrCode = 0x5
http2ErrCodeFrameSize http2ErrCode = 0x6
http2ErrCodeRefusedStream http2ErrCode = 0x7
http2ErrCodeCancel http2ErrCode = 0x8
http2ErrCodeCompression http2ErrCode = 0x9
http2ErrCodeConnect http2ErrCode = 0xa
http2ErrCodeEnhanceYourCalm http2ErrCode = 0xb
http2ErrCodeInadequateSecurity http2ErrCode = 0xc
http2ErrCodeHTTP11Required http2ErrCode = 0xd
)
var http2errCodeName = map[http2ErrCode]string{
http2ErrCodeNo: "NO_ERROR",
http2ErrCodeProtocol: "PROTOCOL_ERROR",
http2ErrCodeInternal: "INTERNAL_ERROR",
http2ErrCodeFlowControl: "FLOW_CONTROL_ERROR",
http2ErrCodeSettingsTimeout: "SETTINGS_TIMEOUT",
http2ErrCodeStreamClosed: "STREAM_CLOSED",
http2ErrCodeFrameSize: "FRAME_SIZE_ERROR",
http2ErrCodeRefusedStream: "REFUSED_STREAM",
http2ErrCodeCancel: "CANCEL",
http2ErrCodeCompression: "COMPRESSION_ERROR",
http2ErrCodeConnect: "CONNECT_ERROR",
http2ErrCodeEnhanceYourCalm: "ENHANCE_YOUR_CALM",
http2ErrCodeInadequateSecurity: "INADEQUATE_SECURITY",
http2ErrCodeHTTP11Required: "HTTP_1_1_REQUIRED",
}
func (e http2ErrCode) String() string {
if s, ok := http2errCodeName[e]; ok {
return s
}
return fmt.Sprintf("unknown error code 0x%x", uint32(e))
}
// ConnectionError is an error that results in the termination of the
// entire connection.
type http2ConnectionError http2ErrCode
func (e http2ConnectionError) Error() string {
return fmt.Sprintf("connection error: %s", http2ErrCode(e))
}
// StreamError is an error that only affects one stream within an
// HTTP/2 connection.
type http2StreamError struct {
StreamID uint32
Code http2ErrCode
}
func (e http2StreamError) Error() string {
return fmt.Sprintf("stream error: stream ID %d; %v", e.StreamID, e.Code)
}
// 6.9.1 The Flow Control Window
// "If a sender receives a WINDOW_UPDATE that causes a flow control
// window to exceed this maximum it MUST terminate either the stream
// or the connection, as appropriate. For streams, [...]; for the
// connection, a GOAWAY frame with a FLOW_CONTROL_ERROR code."
type http2goAwayFlowError struct{}
func (http2goAwayFlowError) Error() string { return "connection exceeded flow control window size" }
// Errors of this type are only returned by the frame parser functions
// and converted into ConnectionError(ErrCodeProtocol).
type http2connError struct {
Code http2ErrCode
Reason string
}
func (e http2connError) Error() string {
return fmt.Sprintf("http2: connection error: %v: %v", e.Code, e.Reason)
}
type http2pseudoHeaderError string
func (e http2pseudoHeaderError) Error() string {
return fmt.Sprintf("invalid pseudo-header %q", string(e))
}
type http2duplicatePseudoHeaderError string
func (e http2duplicatePseudoHeaderError) Error() string {
return fmt.Sprintf("duplicate pseudo-header %q", string(e))
}
type http2headerFieldNameError string
func (e http2headerFieldNameError) Error() string {
return fmt.Sprintf("invalid header field name %q", string(e))
}
type http2headerFieldValueError string
func (e http2headerFieldValueError) Error() string {
return fmt.Sprintf("invalid header field value %q", string(e))
}
var (
http2errMixPseudoHeaderTypes = errors.New("mix of request and response pseudo headers")
http2errPseudoAfterRegular = errors.New("pseudo header field after regular")
)
// fixedBuffer is an io.ReadWriter backed by a fixed size buffer.
// It never allocates, but moves old data as new data is written.
type http2fixedBuffer struct {
buf []byte
r, w int
}
var (
http2errReadEmpty = errors.New("read from empty fixedBuffer")
http2errWriteFull = errors.New("write on full fixedBuffer")
)
// Read copies bytes from the buffer into p.
// It is an error to read when no data is available.
func (b *http2fixedBuffer) Read(p []byte) (n int, err error) {
if b.r == b.w {
return 0, http2errReadEmpty
}
n = copy(p, b.buf[b.r:b.w])
b.r += n
if b.r == b.w {
b.r = 0
b.w = 0
}
return n, nil
}
// Len returns the number of bytes of the unread portion of the buffer.
func (b *http2fixedBuffer) Len() int {
return b.w - b.r
}
// Write copies bytes from p into the buffer.
// It is an error to write more data than the buffer can hold.
func (b *http2fixedBuffer) Write(p []byte) (n int, err error) {
if b.r > 0 && len(p) > len(b.buf)-b.w {
copy(b.buf, b.buf[b.r:b.w])
b.w -= b.r
b.r = 0
}
n = copy(b.buf[b.w:], p)
b.w += n
if n < len(p) {
err = http2errWriteFull
}
return n, err
}
// flow is the flow control window's size.
type http2flow struct {
// n is the number of DATA bytes we're allowed to send.
// A flow is kept both on a conn and a per-stream.
n int32
// conn points to the shared connection-level flow that is
// shared by all streams on that conn. It is nil for the flow
// that's on the conn directly.
conn *http2flow
}
func (f *http2flow) setConnFlow(cf *http2flow) { f.conn = cf }
func (f *http2flow) available() int32 {
n := f.n
if f.conn != nil && f.conn.n < n {
n = f.conn.n
}
return n
}
func (f *http2flow) take(n int32) {
if n > f.available() {
panic("internal error: took too much")
}
f.n -= n
if f.conn != nil {
f.conn.n -= n
}
}
// add adds n bytes (positive or negative) to the flow control window.
// It returns false if the sum would exceed 2^31-1.
func (f *http2flow) add(n int32) bool {
remain := (1<<31 - 1) - f.n
if n > remain {
return false
}
f.n += n
return true
}
const http2frameHeaderLen = 9
var http2padZeros = 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 http2FrameType uint8
const (
http2FrameData http2FrameType = 0x0
http2FrameHeaders http2FrameType = 0x1
http2FramePriority http2FrameType = 0x2
http2FrameRSTStream http2FrameType = 0x3
http2FrameSettings http2FrameType = 0x4
http2FramePushPromise http2FrameType = 0x5
http2FramePing http2FrameType = 0x6
http2FrameGoAway http2FrameType = 0x7
http2FrameWindowUpdate http2FrameType = 0x8
http2FrameContinuation http2FrameType = 0x9
)
var http2frameName = map[http2FrameType]string{
http2FrameData: "DATA",
http2FrameHeaders: "HEADERS",
http2FramePriority: "PRIORITY",
http2FrameRSTStream: "RST_STREAM",
http2FrameSettings: "SETTINGS",
http2FramePushPromise: "PUSH_PROMISE",
http2FramePing: "PING",
http2FrameGoAway: "GOAWAY",
http2FrameWindowUpdate: "WINDOW_UPDATE",
http2FrameContinuation: "CONTINUATION",
}
func (t http2FrameType) String() string {
if s, ok := http2frameName[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 http2Flags uint8
// Has reports whether f contains all (0 or more) flags in v.
func (f http2Flags) Has(v http2Flags) bool {
return (f & v) == v
}
// Frame-specific FrameHeader flag bits.
const (
// Data Frame
http2FlagDataEndStream http2Flags = 0x1
http2FlagDataPadded http2Flags = 0x8
// Headers Frame
http2FlagHeadersEndStream http2Flags = 0x1
http2FlagHeadersEndHeaders http2Flags = 0x4
http2FlagHeadersPadded http2Flags = 0x8
http2FlagHeadersPriority http2Flags = 0x20
// Settings Frame
http2FlagSettingsAck http2Flags = 0x1
// Ping Frame
http2FlagPingAck http2Flags = 0x1
// Continuation Frame
http2FlagContinuationEndHeaders http2Flags = 0x4
http2FlagPushPromiseEndHeaders http2Flags = 0x4
http2FlagPushPromisePadded http2Flags = 0x8
)
var http2flagName = map[http2FrameType]map[http2Flags]string{
http2FrameData: {
http2FlagDataEndStream: "END_STREAM",
http2FlagDataPadded: "PADDED",
},
http2FrameHeaders: {
http2FlagHeadersEndStream: "END_STREAM",
http2FlagHeadersEndHeaders: "END_HEADERS",
http2FlagHeadersPadded: "PADDED",
http2FlagHeadersPriority: "PRIORITY",
},
http2FrameSettings: {
http2FlagSettingsAck: "ACK",
},
http2FramePing: {
http2FlagPingAck: "ACK",
},
http2FrameContinuation: {
http2FlagContinuationEndHeaders: "END_HEADERS",
},
http2FramePushPromise: {
http2FlagPushPromiseEndHeaders: "END_HEADERS",
http2FlagPushPromisePadded: "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 http2frameParser func(fh http2FrameHeader, payload []byte) (http2Frame, error)
var http2frameParsers = map[http2FrameType]http2frameParser{
http2FrameData: http2parseDataFrame,
http2FrameHeaders: http2parseHeadersFrame,
http2FramePriority: http2parsePriorityFrame,
http2FrameRSTStream: http2parseRSTStreamFrame,
http2FrameSettings: http2parseSettingsFrame,
http2FramePushPromise: http2parsePushPromise,
http2FramePing: http2parsePingFrame,
http2FrameGoAway: http2parseGoAwayFrame,
http2FrameWindowUpdate: http2parseWindowUpdateFrame,
http2FrameContinuation: http2parseContinuationFrame,
}
func http2typeFrameParser(t http2FrameType) http2frameParser {
if f := http2frameParsers[t]; f != nil {
return f
}
return http2parseUnknownFrame
}
// A FrameHeader is the 9 byte header of all HTTP/2 frames.
//
// See http://http2.github.io/http2-spec/#FrameHeader
type http2FrameHeader 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 http2FrameType
// Flags are the 1 byte of 8 potential bit flags per frame.
// They are specific to the frame type.
Flags http2Flags
// 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 http2FrameHeader) Header() http2FrameHeader { return h }
func (h http2FrameHeader) String() string {
var buf bytes.Buffer
buf.WriteString("[FrameHeader ")
h.writeDebug(&buf)
buf.WriteByte(']')
return buf.String()
}
func (h http2FrameHeader) 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 := http2flagName[h.Type][http2Flags(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 *http2FrameHeader) checkValid() {
if !h.valid {
panic("Frame accessor called on non-owned Frame")
}
}
func (h *http2FrameHeader) invalidate() { h.valid = false }
// frame header bytes.
// Used only by ReadFrameHeader.
var http2fhBytes = sync.Pool{
New: func() interface{} {
buf := make([]byte, http2frameHeaderLen)
return &buf
},
}
// ReadFrameHeader reads 9 bytes from r and returns a FrameHeader.
// Most users should use Framer.ReadFrame instead.
func http2ReadFrameHeader(r io.Reader) (http2FrameHeader, error) {
bufp := http2fhBytes.Get().(*[]byte)
defer http2fhBytes.Put(bufp)
return http2readFrameHeader(*bufp, r)
}
func http2readFrameHeader(buf []byte, r io.Reader) (http2FrameHeader, error) {
_, err := io.ReadFull(r, buf[:http2frameHeaderLen])
if err != nil {
return http2FrameHeader{}, err
}
return http2FrameHeader{
Length: (uint32(buf[0])<<16 | uint32(buf[1])<<8 | uint32(buf[2])),
Type: http2FrameType(buf[3]),
Flags: http2Flags(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 http2Frame interface {
Header() http2FrameHeader
// 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 http2Framer struct {
r io.Reader
lastFrame http2Frame
errDetail error
// lastHeaderStream is non-zero if the last frame was an
// unfinished HEADERS/CONTINUATION.
lastHeaderStream uint32
maxReadSize uint32
headerBuf [http2frameHeaderLen]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
logReads bool
debugFramer *http2Framer // only use for logging written writes
debugFramerBuf *bytes.Buffer
}
func (fr *http2Framer) maxHeaderListSize() uint32 {
if fr.MaxHeaderListSize == 0 {
return 16 << 20
}
return fr.MaxHeaderListSize
}
func (f *http2Framer) startWrite(ftype http2FrameType, flags http2Flags, streamID uint32) {
f.wbuf = append(f.wbuf[:0],
0,
0,
0,
byte(ftype),
byte(flags),
byte(streamID>>24),
byte(streamID>>16),
byte(streamID>>8),
byte(streamID))
}
func (f *http2Framer) endWrite() error {
length := len(f.wbuf) - http2frameHeaderLen
if length >= (1 << 24) {
return http2ErrFrameTooLarge
}
_ = append(f.wbuf[:0],
byte(length>>16),
byte(length>>8),
byte(length))
if http2logFrameWrites {
f.logWrite()
}
n, err := f.w.Write(f.wbuf)
if err == nil && n != len(f.wbuf) {
err = io.ErrShortWrite
}
return err
}
func (f *http2Framer) logWrite() {
if f.debugFramer == nil {
f.debugFramerBuf = new(bytes.Buffer)
f.debugFramer = http2NewFramer(nil, f.debugFramerBuf)
f.debugFramer.logReads = false
f.debugFramer.AllowIllegalReads = true
}
f.debugFramerBuf.Write(f.wbuf)
fr, err := f.debugFramer.ReadFrame()
if err != nil {
log.Printf("http2: Framer %p: failed to decode just-written frame", f)
return
}
log.Printf("http2: Framer %p: wrote %v", f, http2summarizeFrame(fr))
}
func (f *http2Framer) writeByte(v byte) { f.wbuf = append(f.wbuf, v) }
func (f *http2Framer) writeBytes(v []byte) { f.wbuf = append(f.wbuf, v...) }
func (f *http2Framer) writeUint16(v uint16) { f.wbuf = append(f.wbuf, byte(v>>8), byte(v)) }
func (f *http2Framer) writeUint32(v uint32) {
f.wbuf = append(f.wbuf, byte(v>>24), byte(v>>16), byte(v>>8), byte(v))
}
const (
http2minMaxFrameSize = 1 << 14
http2maxFrameSize = 1<<24 - 1
)
// NewFramer returns a Framer that writes frames to w and reads them from r.
func http2NewFramer(w io.Writer, r io.Reader) *http2Framer {
fr := &http2Framer{
w: w,
r: r,
logReads: http2logFrameReads,
}
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(http2maxFrameSize)
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 *http2Framer) SetMaxReadFrameSize(v uint32) {
if v > http2maxFrameSize {
v = http2maxFrameSize
}
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 *http2Framer) 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 http2ErrFrameTooLarge = errors.New("http2: frame too large")
// terminalReadFrameError reports whether err is an unrecoverable
// error from ReadFrame and no other frames should be read.
func http2terminalReadFrameError(err error) bool {
if _, ok := err.(http2StreamError); 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 from the underlying
// reader.
func (fr *http2Framer) ReadFrame() (http2Frame, error) {
fr.errDetail = nil
if fr.lastFrame != nil {
fr.lastFrame.invalidate()
}
fh, err := http2readFrameHeader(fr.headerBuf[:], fr.r)
if err != nil {
return nil, err
}
if fh.Length > fr.maxReadSize {
return nil, http2ErrFrameTooLarge
}
payload := fr.getReadBuf(fh.Length)
if _, err := io.ReadFull(fr.r, payload); err != nil {
return nil, err
}
f, err := http2typeFrameParser(fh.Type)(fh, payload)
if err != nil {
if ce, ok := err.(http2connError); ok {
return nil, fr.connError(ce.Code, ce.Reason)
}
return nil, err
}
if err := fr.checkFrameOrder(f); err != nil {