tusd/vendor/google.golang.org/grpc/transport/http_util.go

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/*
*
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* Copyright 2014 gRPC authors.
*
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* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
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* http://www.apache.org/licenses/LICENSE-2.0
*
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* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package transport
import (
"bufio"
"bytes"
"encoding/base64"
"fmt"
"io"
"net"
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"net/http"
"strconv"
"strings"
"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/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.
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defaultWriteBufSize = 32 * 1024
defaultReadBufSize = 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,
}
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httpStatusConvTab = map[int]codes.Code{
// 400 Bad Request - INTERNAL.
http.StatusBadRequest: codes.Internal,
// 401 Unauthorized - UNAUTHENTICATED.
http.StatusUnauthorized: codes.Unauthenticated,
// 403 Forbidden - PERMISSION_DENIED.
http.StatusForbidden: codes.PermissionDenied,
// 404 Not Found - UNIMPLEMENTED.
http.StatusNotFound: codes.Unimplemented,
// 429 Too Many Requests - UNAVAILABLE.
http.StatusTooManyRequests: codes.Unavailable,
// 502 Bad Gateway - UNAVAILABLE.
http.StatusBadGateway: codes.Unavailable,
// 503 Service Unavailable - UNAVAILABLE.
http.StatusServiceUnavailable: codes.Unavailable,
// 504 Gateway timeout - UNAVAILABLE.
http.StatusGatewayTimeout: codes.Unavailable,
}
)
// 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.
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rawStatusCode *int
rawStatusMsg string
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httpStatus *int
// Server side only fields.
timeoutSet bool
timeout time.Duration
method string
// key-value metadata map from the peer.
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mdata map[string][]string
statsTags []byte
statsTrace []byte
}
// 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.
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d.statusGen = status.New(codes.Code(int32(*(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
}
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func (d *decodeState) decodeResponseHeader(frame *http2.MetaHeadersFrame) error {
for _, hf := range frame.Fields {
if err := d.processHeaderField(hf); err != nil {
return err
}
}
// If grpc status exists, no need to check further.
if d.rawStatusCode != nil || d.statusGen != nil {
return nil
}
// If grpc status doesn't exist and http status doesn't exist,
// then it's a malformed header.
if d.httpStatus == nil {
return streamErrorf(codes.Internal, "malformed header: doesn't contain status(gRPC or HTTP)")
}
if *(d.httpStatus) != http.StatusOK {
code, ok := httpStatusConvTab[*(d.httpStatus)]
if !ok {
code = codes.Unknown
}
return streamErrorf(code, http.StatusText(*(d.httpStatus)))
}
// gRPC status doesn't exist and http status is OK.
// Set rawStatusCode to be unknown and return nil error.
// So that, if the stream has ended this Unknown status
// will be propogated to the user.
// Otherwise, it will be ignored. In which case, status from
// a later trailer, that has StreamEnded flag set, is propogated.
code := int(codes.Unknown)
d.rawStatusCode = &code
return nil
}
func (d *decodeState) addMetadata(k, v string) {
if d.mdata == nil {
d.mdata = make(map[string][]string)
}
d.mdata[k] = append(d.mdata[k], v)
}
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)
}
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d.rawStatusCode = &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
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case ":status":
code, err := strconv.Atoi(f.Value)
if err != nil {
return streamErrorf(codes.Internal, "transport: malformed http-status: %v", err)
}
d.httpStatus = &code
case "grpc-tags-bin":
v, err := decodeBinHeader(f.Value)
if err != nil {
return streamErrorf(codes.Internal, "transport: malformed grpc-tags-bin: %v", err)
}
d.statsTags = v
d.addMetadata(f.Name, string(v))
case "grpc-trace-bin":
v, err := decodeBinHeader(f.Value)
if err != nil {
return streamErrorf(codes.Internal, "transport: malformed grpc-trace-bin: %v", err)
}
d.statsTrace = v
d.addMetadata(f.Name, string(v))
default:
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if isReservedHeader(f.Name) && !isWhitelistedPseudoHeader(f.Name) {
break
}
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v, err := decodeMetadataHeader(f.Name, f.Value)
if err != nil {
errorf("Failed to decode metadata header (%q, %q): %v", f.Name, f.Value, err)
return nil
}
d.addMetadata(f.Name, string(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
}
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func newFramer(conn net.Conn, writeBufferSize, readBufferSize int) *framer {
f := &framer{
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reader: bufio.NewReaderSize(conn, readBufferSize),
writer: bufio.NewWriterSize(conn, writeBufferSize),
}
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
}