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/*
*
* Copyright 2014 gRPC authors.
*
* 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
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* 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"
"math"
"net"
"net/http"
"strconv"
"strings"
"time"
"unicode/utf8"
"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
// baseContentType is the base content-type for gRPC. This is a valid
// content-type on it's own, but can also include a content-subtype such as
// "proto" as a suffix after "+" or ";". See
// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests
// for more details.
baseContentType = "application/grpc"
)
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.Internal,
}
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,
}
// HTTPStatusConvTab is the HTTP status code to gRPC error code conversion table.
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,
}
)
type parsedHeaderData 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 *int
rawStatusMsg string
httpStatus *int
// Server side only fields.
timeoutSet bool
timeout time.Duration
method string
// key-value metadata map from the peer.
mdata map[string][]string
statsTags []byte
statsTrace []byte
contentSubtype string
// isGRPC field indicates whether the peer is speaking gRPC (otherwise HTTP).
//
// We are in gRPC mode (peer speaking gRPC) if:
// * We are client side and have already received a HEADER frame that indicates gRPC peer.
// * The header contains valid a content-type, i.e. a string starts with "application/grpc"
// And we should handle error specific to gRPC.
//
// Otherwise (i.e. a content-type string starts without "application/grpc", or does not exist), we
// are in HTTP fallback mode, and should handle error specific to HTTP.
isGRPC bool
grpcErr error
httpErr error
contentTypeErr string
}
// decodeState configures decoding criteria and records the decoded data.
type decodeState struct {
// whether decoding on server side or not
serverSide bool
// Records the states during HPACK decoding. It will be filled with info parsed from HTTP HEADERS
// frame once decodeHeader function has been invoked and returned.
data parsedHeaderData
}
// 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",
"user-agent",
"grpc-message-type",
"grpc-encoding",
"grpc-message",
"grpc-status",
"grpc-timeout",
"grpc-status-details-bin",
// Intentionally exclude grpc-previous-rpc-attempts and
// grpc-retry-pushback-ms, which are "reserved", but their API
// intentionally works via metadata.
"te":
return true
default:
return false
}
}
// isWhitelistedHeader checks whether hdr should be propagated into metadata
// visible to users, even though it is classified as "reserved", above.
func isWhitelistedHeader(hdr string) bool {
switch hdr {
case ":authority", "user-agent":
return true
default:
return false
}
}
// contentSubtype returns the content-subtype for the given content-type. The
// given content-type must be a valid content-type that starts with
// "application/grpc". A content-subtype will follow "application/grpc" after a
// "+" or ";". See
// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests for
// more details.
//
// If contentType is not a valid content-type for gRPC, the boolean
// will be false, otherwise true. If content-type == "application/grpc",
// "application/grpc+", or "application/grpc;", the boolean will be true,
// but no content-subtype will be returned.
//
// contentType is assumed to be lowercase already.
func contentSubtype(contentType string) (string, bool) {
if contentType == baseContentType {
return "", true
}
if !strings.HasPrefix(contentType, baseContentType) {
return "", false
}
// guaranteed since != baseContentType and has baseContentType prefix
switch contentType[len(baseContentType)] {
case '+', ';':
// this will return true for "application/grpc+" or "application/grpc;"
// which the previous validContentType function tested to be valid, so we
// just say that no content-subtype is specified in this case
return contentType[len(baseContentType)+1:], true
default:
return "", false
}
}
// contentSubtype is assumed to be lowercase
func contentType(contentSubtype string) string {
if contentSubtype == "" {
return baseContentType
}
return baseContentType + "+" + contentSubtype
}
func (d *decodeState) status() *status.Status {
if d.data.statusGen == nil {
// No status-details were provided; generate status using code/msg.
d.data.statusGen = status.New(codes.Code(int32(*(d.data.rawStatusCode))), d.data.rawStatusMsg)
}
return d.data.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) decodeHeader(frame *http2.MetaHeadersFrame) error {
// frame.Truncated is set to true when framer detects that the current header
// list size hits MaxHeaderListSize limit.
if frame.Truncated {
return status.Error(codes.Internal, "peer header list size exceeded limit")
}
for _, hf := range frame.Fields {
d.processHeaderField(hf)
}
if d.data.isGRPC {
if d.data.grpcErr != nil {
return d.data.grpcErr
}
if d.serverSide {
return nil
}
if d.data.rawStatusCode == nil && d.data.statusGen == nil {
// gRPC status doesn't exist.
// Set rawStatusCode to be unknown and return nil error.
// So that, if the stream has ended this Unknown status
// will be propagated to the user.
// Otherwise, it will be ignored. In which case, status from
// a later trailer, that has StreamEnded flag set, is propagated.
code := int(codes.Unknown)
d.data.rawStatusCode = &code
}
return nil
}
// HTTP fallback mode
if d.data.httpErr != nil {
return d.data.httpErr
}
var (
code = codes.Internal // when header does not include HTTP status, return INTERNAL
ok bool
)
if d.data.httpStatus != nil {
code, ok = HTTPStatusConvTab[*(d.data.httpStatus)]
if !ok {
code = codes.Unknown
}
}
return status.Error(code, d.constructHTTPErrMsg())
}
// constructErrMsg constructs error message to be returned in HTTP fallback mode.
// Format: HTTP status code and its corresponding message + content-type error message.
func (d *decodeState) constructHTTPErrMsg() string {
var errMsgs []string
if d.data.httpStatus == nil {
errMsgs = append(errMsgs, "malformed header: missing HTTP status")
} else {
errMsgs = append(errMsgs, fmt.Sprintf("%s: HTTP status code %d", http.StatusText(*(d.data.httpStatus)), *d.data.httpStatus))
}
if d.data.contentTypeErr == "" {
errMsgs = append(errMsgs, "transport: missing content-type field")
} else {
errMsgs = append(errMsgs, d.data.contentTypeErr)
}
return strings.Join(errMsgs, "; ")
}
func (d *decodeState) addMetadata(k, v string) {
if d.data.mdata == nil {
d.data.mdata = make(map[string][]string)
}
d.data.mdata[k] = append(d.data.mdata[k], v)
}
func (d *decodeState) processHeaderField(f hpack.HeaderField) {
switch f.Name {
case "content-type":
contentSubtype, validContentType := contentSubtype(f.Value)
if !validContentType {
d.data.contentTypeErr = fmt.Sprintf("transport: received the unexpected content-type %q", f.Value)
return
}
d.data.contentSubtype = contentSubtype
// TODO: do we want to propagate the whole content-type in the metadata,
// or come up with a way to just propagate the content-subtype if it was set?
// ie {"content-type": "application/grpc+proto"} or {"content-subtype": "proto"}
// in the metadata?
d.addMetadata(f.Name, f.Value)
d.data.isGRPC = true
case "grpc-encoding":
d.data.encoding = f.Value
case "grpc-status":
code, err := strconv.Atoi(f.Value)
if err != nil {
d.data.grpcErr = status.Errorf(codes.Internal, "transport: malformed grpc-status: %v", err)
return
}
d.data.rawStatusCode = &code
case "grpc-message":
d.data.rawStatusMsg = decodeGrpcMessage(f.Value)
case "grpc-status-details-bin":
v, err := decodeBinHeader(f.Value)
if err != nil {
d.data.grpcErr = status.Errorf(codes.Internal, "transport: malformed grpc-status-details-bin: %v", err)
return
}
s := &spb.Status{}
if err := proto.Unmarshal(v, s); err != nil {
d.data.grpcErr = status.Errorf(codes.Internal, "transport: malformed grpc-status-details-bin: %v", err)
return
}
d.data.statusGen = status.FromProto(s)
case "grpc-timeout":
d.data.timeoutSet = true
var err error
if d.data.timeout, err = decodeTimeout(f.Value); err != nil {
d.data.grpcErr = status.Errorf(codes.Internal, "transport: malformed time-out: %v", err)
}
case ":path":
d.data.method = f.Value
case ":status":
code, err := strconv.Atoi(f.Value)
if err != nil {
d.data.httpErr = status.Errorf(codes.Internal, "transport: malformed http-status: %v", err)
return
}
d.data.httpStatus = &code
case "grpc-tags-bin":
v, err := decodeBinHeader(f.Value)
if err != nil {
d.data.grpcErr = status.Errorf(codes.Internal, "transport: malformed grpc-tags-bin: %v", err)
return
}
d.data.statsTags = v
d.addMetadata(f.Name, string(v))
case "grpc-trace-bin":
v, err := decodeBinHeader(f.Value)
if err != nil {
d.data.grpcErr = status.Errorf(codes.Internal, "transport: malformed grpc-trace-bin: %v", err)
return
}
d.data.statsTrace = v
d.addMetadata(f.Name, string(v))
default:
if isReservedHeader(f.Name) && !isWhitelistedHeader(f.Name) {
break
}
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
}
d.addMetadata(f.Name, v)
}
}
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)
}
if size > 9 {
// Spec allows for 8 digits plus the unit.
return 0, fmt.Errorf("transport: timeout string is too long: %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
}
const maxHours = math.MaxInt64 / int64(time.Hour)
if d == time.Hour && t > maxHours {
// This timeout would overflow math.MaxInt64; clamp it.
return time.Duration(math.MaxInt64), nil
}
return d * time.Duration(t), nil
}
const (
spaceByte = ' '
tildeByte = '~'
percentByte = '%'
)
// encodeGrpcMessage is used to encode status code in header field
// "grpc-message". It does percent encoding and also replaces invalid utf-8
// characters with Unicode replacement character.
//
// 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 <= tildeByte && c != percentByte) {
return encodeGrpcMessageUnchecked(msg)
}
}
return msg
}
func encodeGrpcMessageUnchecked(msg string) string {
var buf bytes.Buffer
for len(msg) > 0 {
r, size := utf8.DecodeRuneInString(msg)
for _, b := range []byte(string(r)) {
if size > 1 {
// If size > 1, r is not ascii. Always do percent encoding.
buf.WriteString(fmt.Sprintf("%%%02X", b))
continue
}
// The for loop is necessary even if size == 1. r could be
// utf8.RuneError.
//
// fmt.Sprintf("%%%02X", utf8.RuneError) gives "%FFFD".
if b >= spaceByte && b <= tildeByte && b != percentByte {
buf.WriteByte(b)
} else {
buf.WriteString(fmt.Sprintf("%%%02X", b))
}
}
msg = msg[size:]
}
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 bufWriter struct {
buf []byte
offset int
batchSize int
conn net.Conn
err error
onFlush func()
}
func newBufWriter(conn net.Conn, batchSize int) *bufWriter {
return &bufWriter{
buf: make([]byte, batchSize*2),
batchSize: batchSize,
conn: conn,
}
}
func (w *bufWriter) Write(b []byte) (n int, err error) {
if w.err != nil {
return 0, w.err
}
if w.batchSize == 0 { // Buffer has been disabled.
return w.conn.Write(b)
}
for len(b) > 0 {
nn := copy(w.buf[w.offset:], b)
b = b[nn:]
w.offset += nn
n += nn
if w.offset >= w.batchSize {
err = w.Flush()
}
}
return n, err
}
func (w *bufWriter) Flush() error {
if w.err != nil {
return w.err
}
if w.offset == 0 {
return nil
}
if w.onFlush != nil {
w.onFlush()
}
_, w.err = w.conn.Write(w.buf[:w.offset])
w.offset = 0
return w.err
}
type framer struct {
writer *bufWriter
fr *http2.Framer
}
func newFramer(conn net.Conn, writeBufferSize, readBufferSize int, maxHeaderListSize uint32) *framer {
if writeBufferSize < 0 {
writeBufferSize = 0
}
var r io.Reader = conn
if readBufferSize > 0 {
r = bufio.NewReaderSize(r, readBufferSize)
}
w := newBufWriter(conn, writeBufferSize)
f := &framer{
writer: w,
fr: http2.NewFramer(w, r),
}
f.fr.SetMaxReadFrameSize(http2MaxFrameLen)
// 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.MaxHeaderListSize = maxHeaderListSize
f.fr.ReadMetaHeaders = hpack.NewDecoder(http2InitHeaderTableSize, nil)
return f
}
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