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/*
*
* Copyright 2014, Google Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
package transport
import (
"bufio"
"bytes"
"encoding/base64"
"fmt"
"io"
"net"
"strconv"
"strings"
"sync/atomic"
"time"
"github.com/golang/protobuf/proto"
"golang.org/x/net/http2"
"golang.org/x/net/http2/hpack"
spb "google.golang.org/genproto/googleapis/rpc/status"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/grpclog"
"google.golang.org/grpc/status"
)
const (
// http2MaxFrameLen specifies the max length of a HTTP2 frame.
http2MaxFrameLen = 16384 // 16KB frame
// http://http2.github.io/http2-spec/#SettingValues
http2InitHeaderTableSize = 4096
// http2IOBufSize specifies the buffer size for sending frames.
http2IOBufSize = 32 * 1024
)
var (
clientPreface = []byte(http2.ClientPreface)
http2ErrConvTab = map[http2.ErrCode]codes.Code{
http2.ErrCodeNo: codes.Internal,
http2.ErrCodeProtocol: codes.Internal,
http2.ErrCodeInternal: codes.Internal,
http2.ErrCodeFlowControl: codes.ResourceExhausted,
http2.ErrCodeSettingsTimeout: codes.Internal,
http2.ErrCodeStreamClosed: codes.Internal,
http2.ErrCodeFrameSize: codes.Internal,
http2.ErrCodeRefusedStream: codes.Unavailable,
http2.ErrCodeCancel: codes.Canceled,
http2.ErrCodeCompression: codes.Internal,
http2.ErrCodeConnect: codes.Internal,
http2.ErrCodeEnhanceYourCalm: codes.ResourceExhausted,
http2.ErrCodeInadequateSecurity: codes.PermissionDenied,
http2.ErrCodeHTTP11Required: codes.FailedPrecondition,
}
statusCodeConvTab = map[codes.Code]http2.ErrCode{
codes.Internal: http2.ErrCodeInternal,
codes.Canceled: http2.ErrCodeCancel,
codes.Unavailable: http2.ErrCodeRefusedStream,
codes.ResourceExhausted: http2.ErrCodeEnhanceYourCalm,
codes.PermissionDenied: http2.ErrCodeInadequateSecurity,
}
)
// Records the states during HPACK decoding. Must be reset once the
// decoding of the entire headers are finished.
type decodeState struct {
encoding string
// statusGen caches the stream status received from the trailer the server
// sent. Client side only. Do not access directly. After all trailers are
// parsed, use the status method to retrieve the status.
statusGen *status.Status
// rawStatusCode and rawStatusMsg are set from the raw trailer fields and are not
// intended for direct access outside of parsing.
rawStatusCode int32
rawStatusMsg string
// Server side only fields.
timeoutSet bool
timeout time.Duration
method string
// key-value metadata map from the peer.
mdata map[string][]string
}
// isReservedHeader checks whether hdr belongs to HTTP2 headers
// reserved by gRPC protocol. Any other headers are classified as the
// user-specified metadata.
func isReservedHeader(hdr string) bool {
if hdr != "" && hdr[0] == ':' {
return true
}
switch hdr {
case "content-type",
"grpc-message-type",
"grpc-encoding",
"grpc-message",
"grpc-status",
"grpc-timeout",
"grpc-status-details-bin",
"te":
return true
default:
return false
}
}
// isWhitelistedPseudoHeader checks whether hdr belongs to HTTP2 pseudoheaders
// that should be propagated into metadata visible to users.
func isWhitelistedPseudoHeader(hdr string) bool {
switch hdr {
case ":authority":
return true
default:
return false
}
}
func validContentType(t string) bool {
e := "application/grpc"
if !strings.HasPrefix(t, e) {
return false
}
// Support variations on the content-type
// (e.g. "application/grpc+blah", "application/grpc;blah").
if len(t) > len(e) && t[len(e)] != '+' && t[len(e)] != ';' {
return false
}
return true
}
func (d *decodeState) status() *status.Status {
if d.statusGen == nil {
// No status-details were provided; generate status using code/msg.
d.statusGen = status.New(codes.Code(d.rawStatusCode), d.rawStatusMsg)
}
return d.statusGen
}
const binHdrSuffix = "-bin"
func encodeBinHeader(v []byte) string {
return base64.RawStdEncoding.EncodeToString(v)
}
func decodeBinHeader(v string) ([]byte, error) {
if len(v)%4 == 0 {
// Input was padded, or padding was not necessary.
return base64.StdEncoding.DecodeString(v)
}
return base64.RawStdEncoding.DecodeString(v)
}
func encodeMetadataHeader(k, v string) string {
if strings.HasSuffix(k, binHdrSuffix) {
return encodeBinHeader(([]byte)(v))
}
return v
}
func decodeMetadataHeader(k, v string) (string, error) {
if strings.HasSuffix(k, binHdrSuffix) {
b, err := decodeBinHeader(v)
return string(b), err
}
return v, nil
}
func (d *decodeState) processHeaderField(f hpack.HeaderField) error {
switch f.Name {
case "content-type":
if !validContentType(f.Value) {
return streamErrorf(codes.FailedPrecondition, "transport: received the unexpected content-type %q", f.Value)
}
case "grpc-encoding":
d.encoding = f.Value
case "grpc-status":
code, err := strconv.Atoi(f.Value)
if err != nil {
return streamErrorf(codes.Internal, "transport: malformed grpc-status: %v", err)
}
d.rawStatusCode = int32(code)
case "grpc-message":
d.rawStatusMsg = decodeGrpcMessage(f.Value)
case "grpc-status-details-bin":
v, err := decodeBinHeader(f.Value)
if err != nil {
return streamErrorf(codes.Internal, "transport: malformed grpc-status-details-bin: %v", err)
}
s := &spb.Status{}
if err := proto.Unmarshal(v, s); err != nil {
return streamErrorf(codes.Internal, "transport: malformed grpc-status-details-bin: %v", err)
}
d.statusGen = status.FromProto(s)
case "grpc-timeout":
d.timeoutSet = true
var err error
if d.timeout, err = decodeTimeout(f.Value); err != nil {
return streamErrorf(codes.Internal, "transport: malformed time-out: %v", err)
}
case ":path":
d.method = f.Value
default:
if !isReservedHeader(f.Name) || isWhitelistedPseudoHeader(f.Name) {
if d.mdata == nil {
d.mdata = make(map[string][]string)
}
v, err := decodeMetadataHeader(f.Name, f.Value)
if err != nil {
grpclog.Printf("Failed to decode (%q, %q): %v", f.Name, f.Value, err)
return nil
}
d.mdata[f.Name] = append(d.mdata[f.Name], v)
}
}
return nil
}
type timeoutUnit uint8
const (
hour timeoutUnit = 'H'
minute timeoutUnit = 'M'
second timeoutUnit = 'S'
millisecond timeoutUnit = 'm'
microsecond timeoutUnit = 'u'
nanosecond timeoutUnit = 'n'
)
func timeoutUnitToDuration(u timeoutUnit) (d time.Duration, ok bool) {
switch u {
case hour:
return time.Hour, true
case minute:
return time.Minute, true
case second:
return time.Second, true
case millisecond:
return time.Millisecond, true
case microsecond:
return time.Microsecond, true
case nanosecond:
return time.Nanosecond, true
default:
}
return
}
const maxTimeoutValue int64 = 100000000 - 1
// div does integer division and round-up the result. Note that this is
// equivalent to (d+r-1)/r but has less chance to overflow.
func div(d, r time.Duration) int64 {
if m := d % r; m > 0 {
return int64(d/r + 1)
}
return int64(d / r)
}
// TODO(zhaoq): It is the simplistic and not bandwidth efficient. Improve it.
func encodeTimeout(t time.Duration) string {
if t <= 0 {
return "0n"
}
if d := div(t, time.Nanosecond); d <= maxTimeoutValue {
return strconv.FormatInt(d, 10) + "n"
}
if d := div(t, time.Microsecond); d <= maxTimeoutValue {
return strconv.FormatInt(d, 10) + "u"
}
if d := div(t, time.Millisecond); d <= maxTimeoutValue {
return strconv.FormatInt(d, 10) + "m"
}
if d := div(t, time.Second); d <= maxTimeoutValue {
return strconv.FormatInt(d, 10) + "S"
}
if d := div(t, time.Minute); d <= maxTimeoutValue {
return strconv.FormatInt(d, 10) + "M"
}
// Note that maxTimeoutValue * time.Hour > MaxInt64.
return strconv.FormatInt(div(t, time.Hour), 10) + "H"
}
func decodeTimeout(s string) (time.Duration, error) {
size := len(s)
if size < 2 {
return 0, fmt.Errorf("transport: timeout string is too short: %q", s)
}
unit := timeoutUnit(s[size-1])
d, ok := timeoutUnitToDuration(unit)
if !ok {
return 0, fmt.Errorf("transport: timeout unit is not recognized: %q", s)
}
t, err := strconv.ParseInt(s[:size-1], 10, 64)
if err != nil {
return 0, err
}
return d * time.Duration(t), nil
}
const (
spaceByte = ' '
tildaByte = '~'
percentByte = '%'
)
// encodeGrpcMessage is used to encode status code in header field
// "grpc-message".
// It checks to see if each individual byte in msg is an
// allowable byte, and then either percent encoding or passing it through.
// When percent encoding, the byte is converted into hexadecimal notation
// with a '%' prepended.
func encodeGrpcMessage(msg string) string {
if msg == "" {
return ""
}
lenMsg := len(msg)
for i := 0; i < lenMsg; i++ {
c := msg[i]
if !(c >= spaceByte && c < tildaByte && c != percentByte) {
return encodeGrpcMessageUnchecked(msg)
}
}
return msg
}
func encodeGrpcMessageUnchecked(msg string) string {
var buf bytes.Buffer
lenMsg := len(msg)
for i := 0; i < lenMsg; i++ {
c := msg[i]
if c >= spaceByte && c < tildaByte && c != percentByte {
buf.WriteByte(c)
} else {
buf.WriteString(fmt.Sprintf("%%%02X", c))
}
}
return buf.String()
}
// decodeGrpcMessage decodes the msg encoded by encodeGrpcMessage.
func decodeGrpcMessage(msg string) string {
if msg == "" {
return ""
}
lenMsg := len(msg)
for i := 0; i < lenMsg; i++ {
if msg[i] == percentByte && i+2 < lenMsg {
return decodeGrpcMessageUnchecked(msg)
}
}
return msg
}
func decodeGrpcMessageUnchecked(msg string) string {
var buf bytes.Buffer
lenMsg := len(msg)
for i := 0; i < lenMsg; i++ {
c := msg[i]
if c == percentByte && i+2 < lenMsg {
parsed, err := strconv.ParseUint(msg[i+1:i+3], 16, 8)
if err != nil {
buf.WriteByte(c)
} else {
buf.WriteByte(byte(parsed))
i += 2
}
} else {
buf.WriteByte(c)
}
}
return buf.String()
}
type framer struct {
numWriters int32
reader io.Reader
writer *bufio.Writer
fr *http2.Framer
}
func newFramer(conn net.Conn) *framer {
f := &framer{
reader: bufio.NewReaderSize(conn, http2IOBufSize),
writer: bufio.NewWriterSize(conn, http2IOBufSize),
}
f.fr = http2.NewFramer(f.writer, f.reader)
// Opt-in to Frame reuse API on framer to reduce garbage.
// Frames aren't safe to read from after a subsequent call to ReadFrame.
f.fr.SetReuseFrames()
f.fr.ReadMetaHeaders = hpack.NewDecoder(http2InitHeaderTableSize, nil)
return f
}
func (f *framer) adjustNumWriters(i int32) int32 {
return atomic.AddInt32(&f.numWriters, i)
}
// The following writeXXX functions can only be called when the caller gets
// unblocked from writableChan channel (i.e., owns the privilege to write).
func (f *framer) writeContinuation(forceFlush bool, streamID uint32, endHeaders bool, headerBlockFragment []byte) error {
if err := f.fr.WriteContinuation(streamID, endHeaders, headerBlockFragment); err != nil {
return err
}
if forceFlush {
return f.writer.Flush()
}
return nil
}
func (f *framer) writeData(forceFlush bool, streamID uint32, endStream bool, data []byte) error {
if err := f.fr.WriteData(streamID, endStream, data); err != nil {
return err
}
if forceFlush {
return f.writer.Flush()
}
return nil
}
func (f *framer) writeGoAway(forceFlush bool, maxStreamID uint32, code http2.ErrCode, debugData []byte) error {
if err := f.fr.WriteGoAway(maxStreamID, code, debugData); err != nil {
return err
}
if forceFlush {
return f.writer.Flush()
}
return nil
}
func (f *framer) writeHeaders(forceFlush bool, p http2.HeadersFrameParam) error {
if err := f.fr.WriteHeaders(p); err != nil {
return err
}
if forceFlush {
return f.writer.Flush()
}
return nil
}
func (f *framer) writePing(forceFlush, ack bool, data [8]byte) error {
if err := f.fr.WritePing(ack, data); err != nil {
return err
}
if forceFlush {
return f.writer.Flush()
}
return nil
}
func (f *framer) writePriority(forceFlush bool, streamID uint32, p http2.PriorityParam) error {
if err := f.fr.WritePriority(streamID, p); err != nil {
return err
}
if forceFlush {
return f.writer.Flush()
}
return nil
}
func (f *framer) writePushPromise(forceFlush bool, p http2.PushPromiseParam) error {
if err := f.fr.WritePushPromise(p); err != nil {
return err
}
if forceFlush {
return f.writer.Flush()
}
return nil
}
func (f *framer) writeRSTStream(forceFlush bool, streamID uint32, code http2.ErrCode) error {
if err := f.fr.WriteRSTStream(streamID, code); err != nil {
return err
}
if forceFlush {
return f.writer.Flush()
}
return nil
}
func (f *framer) writeSettings(forceFlush bool, settings ...http2.Setting) error {
if err := f.fr.WriteSettings(settings...); err != nil {
return err
}
if forceFlush {
return f.writer.Flush()
}
return nil
}
func (f *framer) writeSettingsAck(forceFlush bool) error {
if err := f.fr.WriteSettingsAck(); err != nil {
return err
}
if forceFlush {
return f.writer.Flush()
}
return nil
}
func (f *framer) writeWindowUpdate(forceFlush bool, streamID, incr uint32) error {
if err := f.fr.WriteWindowUpdate(streamID, incr); err != nil {
return err
}
if forceFlush {
return f.writer.Flush()
}
return nil
}
func (f *framer) flushWrite() error {
return f.writer.Flush()
}
func (f *framer) readFrame() (http2.Frame, error) {
return f.fr.ReadFrame()
}
func (f *framer) errorDetail() error {
return f.fr.ErrorDetail()
}