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path: root/src/pkg/net/http/transfer.go
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Diffstat (limited to 'src/pkg/net/http/transfer.go')
-rw-r--r--src/pkg/net/http/transfer.go730
1 files changed, 0 insertions, 730 deletions
diff --git a/src/pkg/net/http/transfer.go b/src/pkg/net/http/transfer.go
deleted file mode 100644
index 7f6368652..000000000
--- a/src/pkg/net/http/transfer.go
+++ /dev/null
@@ -1,730 +0,0 @@
-// Copyright 2009 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 http
-
-import (
- "bufio"
- "bytes"
- "errors"
- "fmt"
- "io"
- "io/ioutil"
- "net/textproto"
- "sort"
- "strconv"
- "strings"
- "sync"
-)
-
-type errorReader struct {
- err error
-}
-
-func (r *errorReader) Read(p []byte) (n int, err error) {
- return 0, r.err
-}
-
-// transferWriter inspects the fields of a user-supplied Request or Response,
-// sanitizes them without changing the user object and provides methods for
-// writing the respective header, body and trailer in wire format.
-type transferWriter struct {
- Method string
- Body io.Reader
- BodyCloser io.Closer
- ResponseToHEAD bool
- ContentLength int64 // -1 means unknown, 0 means exactly none
- Close bool
- TransferEncoding []string
- Trailer Header
-}
-
-func newTransferWriter(r interface{}) (t *transferWriter, err error) {
- t = &transferWriter{}
-
- // Extract relevant fields
- atLeastHTTP11 := false
- switch rr := r.(type) {
- case *Request:
- if rr.ContentLength != 0 && rr.Body == nil {
- return nil, fmt.Errorf("http: Request.ContentLength=%d with nil Body", rr.ContentLength)
- }
- t.Method = rr.Method
- t.Body = rr.Body
- t.BodyCloser = rr.Body
- t.ContentLength = rr.ContentLength
- t.Close = rr.Close
- t.TransferEncoding = rr.TransferEncoding
- t.Trailer = rr.Trailer
- atLeastHTTP11 = rr.ProtoAtLeast(1, 1)
- if t.Body != nil && len(t.TransferEncoding) == 0 && atLeastHTTP11 {
- if t.ContentLength == 0 {
- // Test to see if it's actually zero or just unset.
- var buf [1]byte
- n, rerr := io.ReadFull(t.Body, buf[:])
- if rerr != nil && rerr != io.EOF {
- t.ContentLength = -1
- t.Body = &errorReader{rerr}
- } else if n == 1 {
- // Oh, guess there is data in this Body Reader after all.
- // The ContentLength field just wasn't set.
- // Stich the Body back together again, re-attaching our
- // consumed byte.
- t.ContentLength = -1
- t.Body = io.MultiReader(bytes.NewReader(buf[:]), t.Body)
- } else {
- // Body is actually empty.
- t.Body = nil
- t.BodyCloser = nil
- }
- }
- if t.ContentLength < 0 {
- t.TransferEncoding = []string{"chunked"}
- }
- }
- case *Response:
- if rr.Request != nil {
- t.Method = rr.Request.Method
- }
- t.Body = rr.Body
- t.BodyCloser = rr.Body
- t.ContentLength = rr.ContentLength
- t.Close = rr.Close
- t.TransferEncoding = rr.TransferEncoding
- t.Trailer = rr.Trailer
- atLeastHTTP11 = rr.ProtoAtLeast(1, 1)
- t.ResponseToHEAD = noBodyExpected(t.Method)
- }
-
- // Sanitize Body,ContentLength,TransferEncoding
- if t.ResponseToHEAD {
- t.Body = nil
- if chunked(t.TransferEncoding) {
- t.ContentLength = -1
- }
- } else {
- if !atLeastHTTP11 || t.Body == nil {
- t.TransferEncoding = nil
- }
- if chunked(t.TransferEncoding) {
- t.ContentLength = -1
- } else if t.Body == nil { // no chunking, no body
- t.ContentLength = 0
- }
- }
-
- // Sanitize Trailer
- if !chunked(t.TransferEncoding) {
- t.Trailer = nil
- }
-
- return t, nil
-}
-
-func noBodyExpected(requestMethod string) bool {
- return requestMethod == "HEAD"
-}
-
-func (t *transferWriter) shouldSendContentLength() bool {
- if chunked(t.TransferEncoding) {
- return false
- }
- if t.ContentLength > 0 {
- return true
- }
- // Many servers expect a Content-Length for these methods
- if t.Method == "POST" || t.Method == "PUT" {
- return true
- }
- if t.ContentLength == 0 && isIdentity(t.TransferEncoding) {
- return true
- }
-
- return false
-}
-
-func (t *transferWriter) WriteHeader(w io.Writer) error {
- if t.Close {
- if _, err := io.WriteString(w, "Connection: close\r\n"); err != nil {
- return err
- }
- }
-
- // Write Content-Length and/or Transfer-Encoding whose values are a
- // function of the sanitized field triple (Body, ContentLength,
- // TransferEncoding)
- if t.shouldSendContentLength() {
- if _, err := io.WriteString(w, "Content-Length: "); err != nil {
- return err
- }
- if _, err := io.WriteString(w, strconv.FormatInt(t.ContentLength, 10)+"\r\n"); err != nil {
- return err
- }
- } else if chunked(t.TransferEncoding) {
- if _, err := io.WriteString(w, "Transfer-Encoding: chunked\r\n"); err != nil {
- return err
- }
- }
-
- // Write Trailer header
- if t.Trailer != nil {
- keys := make([]string, 0, len(t.Trailer))
- for k := range t.Trailer {
- k = CanonicalHeaderKey(k)
- switch k {
- case "Transfer-Encoding", "Trailer", "Content-Length":
- return &badStringError{"invalid Trailer key", k}
- }
- keys = append(keys, k)
- }
- if len(keys) > 0 {
- sort.Strings(keys)
- // TODO: could do better allocation-wise here, but trailers are rare,
- // so being lazy for now.
- if _, err := io.WriteString(w, "Trailer: "+strings.Join(keys, ",")+"\r\n"); err != nil {
- return err
- }
- }
- }
-
- return nil
-}
-
-func (t *transferWriter) WriteBody(w io.Writer) error {
- var err error
- var ncopy int64
-
- // Write body
- if t.Body != nil {
- if chunked(t.TransferEncoding) {
- cw := newChunkedWriter(w)
- _, err = io.Copy(cw, t.Body)
- if err == nil {
- err = cw.Close()
- }
- } else if t.ContentLength == -1 {
- ncopy, err = io.Copy(w, t.Body)
- } else {
- ncopy, err = io.Copy(w, io.LimitReader(t.Body, t.ContentLength))
- if err != nil {
- return err
- }
- var nextra int64
- nextra, err = io.Copy(ioutil.Discard, t.Body)
- ncopy += nextra
- }
- if err != nil {
- return err
- }
- if err = t.BodyCloser.Close(); err != nil {
- return err
- }
- }
-
- if !t.ResponseToHEAD && t.ContentLength != -1 && t.ContentLength != ncopy {
- return fmt.Errorf("http: Request.ContentLength=%d with Body length %d",
- t.ContentLength, ncopy)
- }
-
- // TODO(petar): Place trailer writer code here.
- if chunked(t.TransferEncoding) {
- // Write Trailer header
- if t.Trailer != nil {
- if err := t.Trailer.Write(w); err != nil {
- return err
- }
- }
- // Last chunk, empty trailer
- _, err = io.WriteString(w, "\r\n")
- }
- return err
-}
-
-type transferReader struct {
- // Input
- Header Header
- StatusCode int
- RequestMethod string
- ProtoMajor int
- ProtoMinor int
- // Output
- Body io.ReadCloser
- ContentLength int64
- TransferEncoding []string
- Close bool
- Trailer Header
-}
-
-// bodyAllowedForStatus reports whether a given response status code
-// permits a body. See RFC2616, section 4.4.
-func bodyAllowedForStatus(status int) bool {
- switch {
- case status >= 100 && status <= 199:
- return false
- case status == 204:
- return false
- case status == 304:
- return false
- }
- return true
-}
-
-var (
- suppressedHeaders304 = []string{"Content-Type", "Content-Length", "Transfer-Encoding"}
- suppressedHeadersNoBody = []string{"Content-Length", "Transfer-Encoding"}
-)
-
-func suppressedHeaders(status int) []string {
- switch {
- case status == 304:
- // RFC 2616 section 10.3.5: "the response MUST NOT include other entity-headers"
- return suppressedHeaders304
- case !bodyAllowedForStatus(status):
- return suppressedHeadersNoBody
- }
- return nil
-}
-
-// msg is *Request or *Response.
-func readTransfer(msg interface{}, r *bufio.Reader) (err error) {
- t := &transferReader{RequestMethod: "GET"}
-
- // Unify input
- isResponse := false
- switch rr := msg.(type) {
- case *Response:
- t.Header = rr.Header
- t.StatusCode = rr.StatusCode
- t.ProtoMajor = rr.ProtoMajor
- t.ProtoMinor = rr.ProtoMinor
- t.Close = shouldClose(t.ProtoMajor, t.ProtoMinor, t.Header)
- isResponse = true
- if rr.Request != nil {
- t.RequestMethod = rr.Request.Method
- }
- case *Request:
- t.Header = rr.Header
- t.ProtoMajor = rr.ProtoMajor
- t.ProtoMinor = rr.ProtoMinor
- // Transfer semantics for Requests are exactly like those for
- // Responses with status code 200, responding to a GET method
- t.StatusCode = 200
- default:
- panic("unexpected type")
- }
-
- // Default to HTTP/1.1
- if t.ProtoMajor == 0 && t.ProtoMinor == 0 {
- t.ProtoMajor, t.ProtoMinor = 1, 1
- }
-
- // Transfer encoding, content length
- t.TransferEncoding, err = fixTransferEncoding(t.RequestMethod, t.Header)
- if err != nil {
- return err
- }
-
- realLength, err := fixLength(isResponse, t.StatusCode, t.RequestMethod, t.Header, t.TransferEncoding)
- if err != nil {
- return err
- }
- if isResponse && t.RequestMethod == "HEAD" {
- if n, err := parseContentLength(t.Header.get("Content-Length")); err != nil {
- return err
- } else {
- t.ContentLength = n
- }
- } else {
- t.ContentLength = realLength
- }
-
- // Trailer
- t.Trailer, err = fixTrailer(t.Header, t.TransferEncoding)
- if err != nil {
- return err
- }
-
- // If there is no Content-Length or chunked Transfer-Encoding on a *Response
- // and the status is not 1xx, 204 or 304, then the body is unbounded.
- // See RFC2616, section 4.4.
- switch msg.(type) {
- case *Response:
- if realLength == -1 &&
- !chunked(t.TransferEncoding) &&
- bodyAllowedForStatus(t.StatusCode) {
- // Unbounded body.
- t.Close = true
- }
- }
-
- // Prepare body reader. ContentLength < 0 means chunked encoding
- // or close connection when finished, since multipart is not supported yet
- switch {
- case chunked(t.TransferEncoding):
- if noBodyExpected(t.RequestMethod) {
- t.Body = eofReader
- } else {
- t.Body = &body{src: newChunkedReader(r), hdr: msg, r: r, closing: t.Close}
- }
- case realLength == 0:
- t.Body = eofReader
- case realLength > 0:
- t.Body = &body{src: io.LimitReader(r, realLength), closing: t.Close}
- default:
- // realLength < 0, i.e. "Content-Length" not mentioned in header
- if t.Close {
- // Close semantics (i.e. HTTP/1.0)
- t.Body = &body{src: r, closing: t.Close}
- } else {
- // Persistent connection (i.e. HTTP/1.1)
- t.Body = eofReader
- }
- }
-
- // Unify output
- switch rr := msg.(type) {
- case *Request:
- rr.Body = t.Body
- rr.ContentLength = t.ContentLength
- rr.TransferEncoding = t.TransferEncoding
- rr.Close = t.Close
- rr.Trailer = t.Trailer
- case *Response:
- rr.Body = t.Body
- rr.ContentLength = t.ContentLength
- rr.TransferEncoding = t.TransferEncoding
- rr.Close = t.Close
- rr.Trailer = t.Trailer
- }
-
- return nil
-}
-
-// Checks whether chunked is part of the encodings stack
-func chunked(te []string) bool { return len(te) > 0 && te[0] == "chunked" }
-
-// Checks whether the encoding is explicitly "identity".
-func isIdentity(te []string) bool { return len(te) == 1 && te[0] == "identity" }
-
-// Sanitize transfer encoding
-func fixTransferEncoding(requestMethod string, header Header) ([]string, error) {
- raw, present := header["Transfer-Encoding"]
- if !present {
- return nil, nil
- }
-
- delete(header, "Transfer-Encoding")
-
- encodings := strings.Split(raw[0], ",")
- te := make([]string, 0, len(encodings))
- // TODO: Even though we only support "identity" and "chunked"
- // encodings, the loop below is designed with foresight. One
- // invariant that must be maintained is that, if present,
- // chunked encoding must always come first.
- for _, encoding := range encodings {
- encoding = strings.ToLower(strings.TrimSpace(encoding))
- // "identity" encoding is not recorded
- if encoding == "identity" {
- break
- }
- if encoding != "chunked" {
- return nil, &badStringError{"unsupported transfer encoding", encoding}
- }
- te = te[0 : len(te)+1]
- te[len(te)-1] = encoding
- }
- if len(te) > 1 {
- return nil, &badStringError{"too many transfer encodings", strings.Join(te, ",")}
- }
- if len(te) > 0 {
- // Chunked encoding trumps Content-Length. See RFC 2616
- // Section 4.4. Currently len(te) > 0 implies chunked
- // encoding.
- delete(header, "Content-Length")
- return te, nil
- }
-
- return nil, nil
-}
-
-// Determine the expected body length, using RFC 2616 Section 4.4. This
-// function is not a method, because ultimately it should be shared by
-// ReadResponse and ReadRequest.
-func fixLength(isResponse bool, status int, requestMethod string, header Header, te []string) (int64, error) {
-
- // Logic based on response type or status
- if noBodyExpected(requestMethod) {
- return 0, nil
- }
- if status/100 == 1 {
- return 0, nil
- }
- switch status {
- case 204, 304:
- return 0, nil
- }
-
- // Logic based on Transfer-Encoding
- if chunked(te) {
- return -1, nil
- }
-
- // Logic based on Content-Length
- cl := strings.TrimSpace(header.get("Content-Length"))
- if cl != "" {
- n, err := parseContentLength(cl)
- if err != nil {
- return -1, err
- }
- return n, nil
- } else {
- header.Del("Content-Length")
- }
-
- if !isResponse && requestMethod == "GET" {
- // RFC 2616 doesn't explicitly permit nor forbid an
- // entity-body on a GET request so we permit one if
- // declared, but we default to 0 here (not -1 below)
- // if there's no mention of a body.
- return 0, nil
- }
-
- // Body-EOF logic based on other methods (like closing, or chunked coding)
- return -1, nil
-}
-
-// Determine whether to hang up after sending a request and body, or
-// receiving a response and body
-// 'header' is the request headers
-func shouldClose(major, minor int, header Header) bool {
- if major < 1 {
- return true
- } else if major == 1 && minor == 0 {
- if !strings.Contains(strings.ToLower(header.get("Connection")), "keep-alive") {
- return true
- }
- return false
- } else {
- // TODO: Should split on commas, toss surrounding white space,
- // and check each field.
- if strings.ToLower(header.get("Connection")) == "close" {
- header.Del("Connection")
- return true
- }
- }
- return false
-}
-
-// Parse the trailer header
-func fixTrailer(header Header, te []string) (Header, error) {
- raw := header.get("Trailer")
- if raw == "" {
- return nil, nil
- }
-
- header.Del("Trailer")
- trailer := make(Header)
- keys := strings.Split(raw, ",")
- for _, key := range keys {
- key = CanonicalHeaderKey(strings.TrimSpace(key))
- switch key {
- case "Transfer-Encoding", "Trailer", "Content-Length":
- return nil, &badStringError{"bad trailer key", key}
- }
- trailer[key] = nil
- }
- if len(trailer) == 0 {
- return nil, nil
- }
- if !chunked(te) {
- // Trailer and no chunking
- return nil, ErrUnexpectedTrailer
- }
- return trailer, nil
-}
-
-// body turns a Reader into a ReadCloser.
-// Close ensures that the body has been fully read
-// and then reads the trailer if necessary.
-type body struct {
- src io.Reader
- hdr interface{} // non-nil (Response or Request) value means read trailer
- r *bufio.Reader // underlying wire-format reader for the trailer
- closing bool // is the connection to be closed after reading body?
-
- mu sync.Mutex // guards closed, and calls to Read and Close
- closed bool
-}
-
-// ErrBodyReadAfterClose is returned when reading a Request or Response
-// Body after the body has been closed. This typically happens when the body is
-// read after an HTTP Handler calls WriteHeader or Write on its
-// ResponseWriter.
-var ErrBodyReadAfterClose = errors.New("http: invalid Read on closed Body")
-
-func (b *body) Read(p []byte) (n int, err error) {
- b.mu.Lock()
- defer b.mu.Unlock()
- if b.closed {
- return 0, ErrBodyReadAfterClose
- }
- return b.readLocked(p)
-}
-
-// Must hold b.mu.
-func (b *body) readLocked(p []byte) (n int, err error) {
- n, err = b.src.Read(p)
-
- if err == io.EOF {
- // Chunked case. Read the trailer.
- if b.hdr != nil {
- if e := b.readTrailer(); e != nil {
- err = e
- }
- b.hdr = nil
- } else {
- // If the server declared the Content-Length, our body is a LimitedReader
- // and we need to check whether this EOF arrived early.
- if lr, ok := b.src.(*io.LimitedReader); ok && lr.N > 0 {
- err = io.ErrUnexpectedEOF
- }
- }
- }
-
- // If we can return an EOF here along with the read data, do
- // so. This is optional per the io.Reader contract, but doing
- // so helps the HTTP transport code recycle its connection
- // earlier (since it will see this EOF itself), even if the
- // client doesn't do future reads or Close.
- if err == nil && n > 0 {
- if lr, ok := b.src.(*io.LimitedReader); ok && lr.N == 0 {
- err = io.EOF
- }
- }
-
- return n, err
-}
-
-var (
- singleCRLF = []byte("\r\n")
- doubleCRLF = []byte("\r\n\r\n")
-)
-
-func seeUpcomingDoubleCRLF(r *bufio.Reader) bool {
- for peekSize := 4; ; peekSize++ {
- // This loop stops when Peek returns an error,
- // which it does when r's buffer has been filled.
- buf, err := r.Peek(peekSize)
- if bytes.HasSuffix(buf, doubleCRLF) {
- return true
- }
- if err != nil {
- break
- }
- }
- return false
-}
-
-var errTrailerEOF = errors.New("http: unexpected EOF reading trailer")
-
-func (b *body) readTrailer() error {
- // The common case, since nobody uses trailers.
- buf, err := b.r.Peek(2)
- if bytes.Equal(buf, singleCRLF) {
- b.r.ReadByte()
- b.r.ReadByte()
- return nil
- }
- if len(buf) < 2 {
- return errTrailerEOF
- }
- if err != nil {
- return err
- }
-
- // Make sure there's a header terminator coming up, to prevent
- // a DoS with an unbounded size Trailer. It's not easy to
- // slip in a LimitReader here, as textproto.NewReader requires
- // a concrete *bufio.Reader. Also, we can't get all the way
- // back up to our conn's LimitedReader that *might* be backing
- // this bufio.Reader. Instead, a hack: we iteratively Peek up
- // to the bufio.Reader's max size, looking for a double CRLF.
- // This limits the trailer to the underlying buffer size, typically 4kB.
- if !seeUpcomingDoubleCRLF(b.r) {
- return errors.New("http: suspiciously long trailer after chunked body")
- }
-
- hdr, err := textproto.NewReader(b.r).ReadMIMEHeader()
- if err != nil {
- if err == io.EOF {
- return errTrailerEOF
- }
- return err
- }
- switch rr := b.hdr.(type) {
- case *Request:
- mergeSetHeader(&rr.Trailer, Header(hdr))
- case *Response:
- mergeSetHeader(&rr.Trailer, Header(hdr))
- }
- return nil
-}
-
-func mergeSetHeader(dst *Header, src Header) {
- if *dst == nil {
- *dst = src
- return
- }
- for k, vv := range src {
- (*dst)[k] = vv
- }
-}
-
-func (b *body) Close() error {
- b.mu.Lock()
- defer b.mu.Unlock()
- if b.closed {
- return nil
- }
- var err error
- switch {
- case b.hdr == nil && b.closing:
- // no trailer and closing the connection next.
- // no point in reading to EOF.
- default:
- // Fully consume the body, which will also lead to us reading
- // the trailer headers after the body, if present.
- _, err = io.Copy(ioutil.Discard, bodyLocked{b})
- }
- b.closed = true
- return err
-}
-
-// bodyLocked is a io.Reader reading from a *body when its mutex is
-// already held.
-type bodyLocked struct {
- b *body
-}
-
-func (bl bodyLocked) Read(p []byte) (n int, err error) {
- if bl.b.closed {
- return 0, ErrBodyReadAfterClose
- }
- return bl.b.readLocked(p)
-}
-
-// parseContentLength trims whitespace from s and returns -1 if no value
-// is set, or the value if it's >= 0.
-func parseContentLength(cl string) (int64, error) {
- cl = strings.TrimSpace(cl)
- if cl == "" {
- return -1, nil
- }
- n, err := strconv.ParseInt(cl, 10, 64)
- if err != nil || n < 0 {
- return 0, &badStringError{"bad Content-Length", cl}
- }
- return n, nil
-
-}
generated by cgit v1.2.3 (git 2.39.1) at 2025-04-29 07:17:48 +0000