Imported Upstream version 57upstream/57

2 files changed, 194 insertions, 128 deletions

diff --git a/src/pkg/mime/multipart/multipart.go b/src/pkg/mime/multipart/multipart.go
index e0b747c3f..60329fe17 100644
--- a/src/pkg/mime/multipart/multipart.go
+++ b/src/pkg/mime/multipart/multipart.go
@@ -15,13 +15,13 @@ package multipart
 import (
 	"bufio"
 	"bytes"
+	"fmt"
 	"io"
 	"io/ioutil"
 	"mime"
 	"net/textproto"
 	"os"
 	"regexp"
-	"strings"
 )
 
 var headerRegexp *regexp.Regexp = regexp.MustCompile("^([a-zA-Z0-9\\-]+): *([^\r\n]+)")
@@ -79,25 +79,28 @@ func (p *Part) FormName() string {
 // NewReader creates a new multipart Reader reading from r using the
 // given MIME boundary.
 func NewReader(reader io.Reader, boundary string) Reader {
+	b := []byte("\r\n--" + boundary + "--")
 	return &multiReader{
-		boundary:     boundary,
-		dashBoundary: "--" + boundary,
-		endLine:      "--" + boundary + "--",
-		bufReader:    bufio.NewReader(reader),
+		bufReader: bufio.NewReader(reader),
+
+		nlDashBoundary:   b[:len(b)-2],
+		dashBoundaryDash: b[2:],
+		dashBoundary:     b[2 : len(b)-2],
 	}
 }
 
 // Implementation ....
 
-func newPart(mr *multiReader) (bp *Part, err os.Error) {
-	bp = new(Part)
-	bp.Header = make(map[string][]string)
-	bp.mr = mr
-	bp.buffer = new(bytes.Buffer)
-	if err = bp.populateHeaders(); err != nil {
-		bp = nil
+func newPart(mr *multiReader) (*Part, os.Error) {
+	bp := &Part{
+		Header: make(map[string][]string),
+		mr:     mr,
+		buffer: new(bytes.Buffer),
 	}
-	return
+	if err := bp.populateHeaders(); err != nil {
+		return nil, err
+	}
+	return bp, nil
 }
 
 func (bp *Part) populateHeaders() os.Error {
@@ -122,44 +125,49 @@ func (bp *Part) populateHeaders() os.Error {
 // Read reads the body of a part, after its headers and before the
 // next part (if any) begins.
 func (bp *Part) Read(p []byte) (n int, err os.Error) {
-	for {
-		if bp.buffer.Len() >= len(p) {
-			// Internal buffer of unconsumed data is large enough for
-			// the read request.  No need to parse more at the moment.
-			break
-		}
-		if !bp.mr.ensureBufferedLine() {
-			return 0, io.ErrUnexpectedEOF
-		}
-		if bp.mr.bufferedLineIsBoundary() {
-			// Don't consume this line
-			break
-		}
+	if bp.buffer.Len() >= len(p) {
+		// Internal buffer of unconsumed data is large enough for
+		// the read request.  No need to parse more at the moment.
+		return bp.buffer.Read(p)
+	}
+	peek, err := bp.mr.bufReader.Peek(4096) // TODO(bradfitz): add buffer size accessor
+	unexpectedEof := err == os.EOF
+	if err != nil && !unexpectedEof {
+		return 0, fmt.Errorf("multipart: Part Read: %v", err)
+	}
+	if peek == nil {
+		panic("nil peek buf")
+	}
 
-		// Write all of this line, except the final CRLF
-		s := *bp.mr.bufferedLine
-		if strings.HasSuffix(s, "\r\n") {
-			bp.mr.consumeLine()
-			if !bp.mr.ensureBufferedLine() {
-				return 0, io.ErrUnexpectedEOF
-			}
-			if bp.mr.bufferedLineIsBoundary() {
-				// The final \r\n isn't ours.  It logically belongs
-				// to the boundary line which follows.
-				bp.buffer.WriteString(s[0 : len(s)-2])
-			} else {
-				bp.buffer.WriteString(s)
-			}
-			break
-		}
-		if strings.HasSuffix(s, "\n") {
-			bp.buffer.WriteString(s)
-			bp.mr.consumeLine()
-			continue
+	// Search the peek buffer for "\r\n--boundary". If found,
+	// consume everything up to the boundary. If not, consume only
+	// as much of the peek buffer as cannot hold the boundary
+	// string.
+	nCopy := 0
+	foundBoundary := false
+	if idx := bytes.Index(peek, bp.mr.nlDashBoundary); idx != -1 {
+		nCopy = idx
+		foundBoundary = true
+	} else if safeCount := len(peek) - len(bp.mr.nlDashBoundary); safeCount > 0 {
+		nCopy = safeCount
+	} else if unexpectedEof {
+		// If we've run out of peek buffer and the boundary
+		// wasn't found (and can't possibly fit), we must have
+		// hit the end of the file unexpectedly.
+		return 0, io.ErrUnexpectedEOF
+	}
+	if nCopy > 0 {
+		if _, err := io.Copyn(bp.buffer, bp.mr.bufReader, int64(nCopy)); err != nil {
+			return 0, err
 		}
-		return 0, os.NewError("multipart parse error during Read; unexpected line: " + s)
 	}
-	return bp.buffer.Read(p)
+	n, err = bp.buffer.Read(p)
+	if err == os.EOF && !foundBoundary {
+		// If the boundary hasn't been reached there's more to
+		// read, so don't pass through an EOF from the buffer
+		err = nil
+	}
+	return
 }
 
 func (bp *Part) Close() os.Error {
@@ -168,46 +176,12 @@ func (bp *Part) Close() os.Error {
 }
 
 type multiReader struct {
-	boundary     string
-	dashBoundary string // --boundary
-	endLine      string // --boundary--
+	bufReader *bufio.Reader
 
-	bufferedLine *string
-
-	bufReader   *bufio.Reader
 	currentPart *Part
 	partsRead   int
-}
 
-func (mr *multiReader) eof() bool {
-	return mr.bufferedLine == nil &&
-		!mr.readLine()
-}
-
-func (mr *multiReader) readLine() bool {
-	lineBytes, err := mr.bufReader.ReadSlice('\n')
-	if err != nil {
-		// TODO: care about err being EOF or not?
-		return false
-	}
-	line := string(lineBytes)
-	mr.bufferedLine = &line
-	return true
-}
-
-func (mr *multiReader) bufferedLineIsBoundary() bool {
-	return strings.HasPrefix(*mr.bufferedLine, mr.dashBoundary)
-}
-
-func (mr *multiReader) ensureBufferedLine() bool {
-	if mr.bufferedLine == nil {
-		return mr.readLine()
-	}
-	return true
-}
-
-func (mr *multiReader) consumeLine() {
-	mr.bufferedLine = nil
+	nlDashBoundary, dashBoundaryDash, dashBoundary []byte
 }
 
 func (mr *multiReader) NextPart() (*Part, os.Error) {
@@ -215,13 +189,14 @@ func (mr *multiReader) NextPart() (*Part, os.Error) {
 		mr.currentPart.Close()
 	}
 
+	expectNewPart := false
 	for {
-		if mr.eof() {
-			return nil, io.ErrUnexpectedEOF
+		line, err := mr.bufReader.ReadSlice('\n')
+		if err != nil {
+			return nil, fmt.Errorf("multipart: NextPart: %v", err)
 		}
 
-		if isBoundaryDelimiterLine(*mr.bufferedLine, mr.dashBoundary) {
-			mr.consumeLine()
+		if mr.isBoundaryDelimiterLine(line) {
 			mr.partsRead++
 			bp, err := newPart(mr)
 			if err != nil {
@@ -231,55 +206,67 @@ func (mr *multiReader) NextPart() (*Part, os.Error) {
 			return bp, nil
 		}
 
-		if hasPrefixThenNewline(*mr.bufferedLine, mr.endLine) {
-			mr.consumeLine()
+		if hasPrefixThenNewline(line, mr.dashBoundaryDash) {
 			// Expected EOF (no error)
+			// TODO(bradfitz): should return an os.EOF error here, not using nil for errors
 			return nil, nil
 		}
 
+		if expectNewPart {
+			return nil, fmt.Errorf("multipart: expecting a new Part; got line %q", string(line))
+		}
+
 		if mr.partsRead == 0 {
 			// skip line
-			mr.consumeLine()
 			continue
 		}
 
-		return nil, os.NewError("Unexpected line in Next().")
+		if bytes.Equal(line, []byte("\r\n")) {
+			// Consume the "\r\n" separator between the
+			// body of the previous part and the boundary
+			// line we now expect will follow. (either a
+			// new part or the end boundary)
+			expectNewPart = true
+			continue
+		}
+
+		return nil, fmt.Errorf("multipart: unexpected line in Next(): %q", line)
 	}
 	panic("unreachable")
 }
 
-func isBoundaryDelimiterLine(line, dashPrefix string) bool {
+func (mr *multiReader) isBoundaryDelimiterLine(line []byte) bool {
 	// http://tools.ietf.org/html/rfc2046#section-5.1
 	//   The boundary delimiter line is then defined as a line
 	//   consisting entirely of two hyphen characters ("-",
 	//   decimal value 45) followed by the boundary parameter
 	//   value from the Content-Type header field, optional linear
 	//   whitespace, and a terminating CRLF.
-	if !strings.HasPrefix(line, dashPrefix) {
+	if !bytes.HasPrefix(line, mr.dashBoundary) {
 		return false
 	}
-	if strings.HasSuffix(line, "\r\n") {
-		return onlyHorizontalWhitespace(line[len(dashPrefix) : len(line)-2])
+	if bytes.HasSuffix(line, []byte("\r\n")) {
+		return onlyHorizontalWhitespace(line[len(mr.dashBoundary) : len(line)-2])
 	}
 	// Violate the spec and also support newlines without the
 	// carriage return...
-	if strings.HasSuffix(line, "\n") {
-		return onlyHorizontalWhitespace(line[len(dashPrefix) : len(line)-1])
+	if bytes.HasSuffix(line, []byte("\n")) {
+		return onlyHorizontalWhitespace(line[len(mr.dashBoundary) : len(line)-1])
 	}
 	return false
 }
 
-func onlyHorizontalWhitespace(s string) bool {
-	for i := 0; i < len(s); i++ {
-		if s[i] != ' ' && s[i] != '\t' {
+func onlyHorizontalWhitespace(s []byte) bool {
+	for _, b := range s {
+		if b != ' ' && b != '\t' {
 			return false
 		}
 	}
 	return true
 }
 
-func hasPrefixThenNewline(s, prefix string) bool {
-	return strings.HasPrefix(s, prefix) &&
-		(len(s) == len(prefix)+1 && strings.HasSuffix(s, "\n") ||
-			len(s) == len(prefix)+2 && strings.HasSuffix(s, "\r\n"))
+func hasPrefixThenNewline(s, prefix []byte) bool {
+	return bytes.HasPrefix(s, prefix) &&
+		(len(s) == len(prefix)+1 && s[len(s)-1] == '\n' ||
+			len(s) == len(prefix)+2 && bytes.HasSuffix(s, []byte("\r\n")))
 }
diff --git a/src/pkg/mime/multipart/multipart_test.go b/src/pkg/mime/multipart/multipart_test.go
index f8f10f3e1..16249146c 100644
--- a/src/pkg/mime/multipart/multipart_test.go
+++ b/src/pkg/mime/multipart/multipart_test.go
@@ -8,38 +8,37 @@ import (
 	"bytes"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"json"
 	"os"
-	"regexp"
 	"strings"
 	"testing"
 )
 
 func TestHorizontalWhitespace(t *testing.T) {
-	if !onlyHorizontalWhitespace(" \t") {
+	if !onlyHorizontalWhitespace([]byte(" \t")) {
 		t.Error("expected pass")
 	}
-	if onlyHorizontalWhitespace("foo bar") {
+	if onlyHorizontalWhitespace([]byte("foo bar")) {
 		t.Error("expected failure")
 	}
 }
 
 func TestBoundaryLine(t *testing.T) {
-	boundary := "myBoundary"
-	prefix := "--" + boundary
-	if !isBoundaryDelimiterLine("--myBoundary\r\n", prefix) {
+	mr := NewReader(strings.NewReader(""), "myBoundary").(*multiReader)
+	if !mr.isBoundaryDelimiterLine([]byte("--myBoundary\r\n")) {
 		t.Error("expected")
 	}
-	if !isBoundaryDelimiterLine("--myBoundary \r\n", prefix) {
+	if !mr.isBoundaryDelimiterLine([]byte("--myBoundary \r\n")) {
 		t.Error("expected")
 	}
-	if !isBoundaryDelimiterLine("--myBoundary \n", prefix) {
+	if !mr.isBoundaryDelimiterLine([]byte("--myBoundary \n")) {
 		t.Error("expected")
 	}
-	if isBoundaryDelimiterLine("--myBoundary bogus \n", prefix) {
+	if mr.isBoundaryDelimiterLine([]byte("--myBoundary bogus \n")) {
 		t.Error("expected fail")
 	}
-	if isBoundaryDelimiterLine("--myBoundary bogus--", prefix) {
+	if mr.isBoundaryDelimiterLine([]byte("--myBoundary bogus--")) {
 		t.Error("expected fail")
 	}
 }
@@ -79,7 +78,9 @@ func TestFormName(t *testing.T) {
 	}
 }
 
-func TestMultipart(t *testing.T) {
+var longLine = strings.Repeat("\n\n\r\r\r\n\r\000", (1<<20)/8)
+
+func testMultipartBody() string {
 	testBody := `
 This is a multi-part message.  This line is ignored.
 --MyBoundary
@@ -90,6 +91,10 @@ foo-bar: baz
 My value
 The end.
 --MyBoundary
+name: bigsection
+
+[longline]
+--MyBoundary
 Header1: value1b
 HEADER2: value2b
 foo-bar: bazb
@@ -102,11 +107,26 @@ Line 3 ends in a newline, but just one.
 
 never read data
 --MyBoundary--
+
+
+useless trailer
 `
-	testBody = regexp.MustCompile("\n").ReplaceAllString(testBody, "\r\n")
-	bodyReader := strings.NewReader(testBody)
+	testBody = strings.Replace(testBody, "\n", "\r\n", -1)
+	return strings.Replace(testBody, "[longline]", longLine, 1)
+}
+
+func TestMultipart(t *testing.T) {
+	bodyReader := strings.NewReader(testMultipartBody())
+	testMultipart(t, bodyReader)
+}
+
+func TestMultipartSlowInput(t *testing.T) {
+	bodyReader := strings.NewReader(testMultipartBody())
+	testMultipart(t, &slowReader{bodyReader})
+}
 
-	reader := NewReader(bodyReader, "MyBoundary")
+func testMultipart(t *testing.T, r io.Reader) {
+	reader := NewReader(r, "MyBoundary")
 	buf := new(bytes.Buffer)
 
 	// Part1
@@ -125,38 +145,64 @@ never read data
 		t.Error("Expected Foo-Bar: baz")
 	}
 	buf.Reset()
-	io.Copy(buf, part)
+	if _, err := io.Copy(buf, part); err != nil {
+		t.Errorf("part 1 copy: %v", err)
+	}
 	expectEq(t, "My value\r\nThe end.",
 		buf.String(), "Value of first part")
 
 	// Part2
 	part, err = reader.NextPart()
+	if err != nil {
+		t.Fatalf("Expected part2; got: %v", err)
+		return
+	}
+	if e, g := "bigsection", part.Header.Get("name"); e != g {
+		t.Errorf("part2's name header: expected %q, got %q", e, g)
+	}
+	buf.Reset()
+	if _, err := io.Copy(buf, part); err != nil {
+		t.Errorf("part 2 copy: %v", err)
+	}
+	s := buf.String()
+	if len(s) != len(longLine) {
+		t.Errorf("part2 body expected long line of length %d; got length %d",
+			len(longLine), len(s))
+	}
+	if s != longLine {
+		t.Errorf("part2 long body didn't match")
+	}
+
+	// Part3
+	part, err = reader.NextPart()
 	if part == nil || err != nil {
-		t.Error("Expected part2")
+		t.Error("Expected part3")
 		return
 	}
 	if part.Header.Get("foo-bar") != "bazb" {
 		t.Error("Expected foo-bar: bazb")
 	}
 	buf.Reset()
-	io.Copy(buf, part)
+	if _, err := io.Copy(buf, part); err != nil {
+		t.Errorf("part 3 copy: %v", err)
+	}
 	expectEq(t, "Line 1\r\nLine 2\r\nLine 3 ends in a newline, but just one.\r\n",
-		buf.String(), "Value of second part")
+		buf.String(), "body of part 3")
 
-	// Part3
+	// Part4
 	part, err = reader.NextPart()
 	if part == nil || err != nil {
-		t.Error("Expected part3 without errors")
+		t.Error("Expected part 4 without errors")
 		return
 	}
 
-	// Non-existent part4
+	// Non-existent part5
 	part, err = reader.NextPart()
 	if part != nil {
-		t.Error("Didn't expect a third part.")
+		t.Error("Didn't expect a fifth part.")
 	}
 	if err != nil {
-		t.Errorf("Unexpected error getting third part: %v", err)
+		t.Errorf("Unexpected error getting fifth part: %v", err)
 	}
 }
 
@@ -237,3 +283,36 @@ func TestLineLimit(t *testing.T) {
 		t.Errorf("expected to read < %d bytes; read %d", maxReadThreshold, mr.n)
 	}
 }
+
+func TestMultipartTruncated(t *testing.T) {
+	testBody := `
+This is a multi-part message.  This line is ignored.
+--MyBoundary
+foo-bar: baz
+
+Oh no, premature EOF!
+`
+	body := strings.Replace(testBody, "\n", "\r\n", -1)
+	bodyReader := strings.NewReader(body)
+	r := NewReader(bodyReader, "MyBoundary")
+
+	part, err := r.NextPart()
+	if err != nil {
+		t.Fatalf("didn't get a part")
+	}
+	_, err = io.Copy(ioutil.Discard, part)
+	if err != io.ErrUnexpectedEOF {
+		t.Fatalf("expected error io.ErrUnexpectedEOF; got %v", err)
+	}
+}
+
+type slowReader struct {
+	r io.Reader
+}
+
+func (s *slowReader) Read(p []byte) (int, os.Error) {
+	if len(p) == 0 {
+		return s.r.Read(p)
+	}
+	return s.r.Read(p[:1])
+}