--- /dev/null
+// Copyright 2011 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 multipart
+
+import (
+ "bytes"
+ "io"
+ "io/ioutil"
+ "net/textproto"
+ "os"
+)
+
+// TODO(adg,bradfitz): find a way to unify the DoS-prevention strategy here
+// with that of the http package's ParseForm.
+
+// ReadForm parses an entire multipart message whose parts have
+// a Content-Disposition of "form-data".
+// It stores up to maxMemory bytes of the file parts in memory
+// and the remainder on disk in temporary files.
+func (r *multiReader) ReadForm(maxMemory int64) (f *Form, err os.Error) {
+ form := &Form{make(map[string][]string), make(map[string][]*FileHeader)}
+ defer func() {
+ if err != nil {
+ form.RemoveAll()
+ }
+ }()
+
+ maxValueBytes := int64(10 << 20) // 10 MB is a lot of text.
+ for {
+ p, err := r.NextPart()
+ if err != nil {
+ return nil, err
+ }
+ if p == nil {
+ break
+ }
+
+ name := p.FormName()
+ if name == "" {
+ continue
+ }
+ var filename string
+ if p.dispositionParams != nil {
+ filename = p.dispositionParams["filename"]
+ }
+
+ var b bytes.Buffer
+
+ if filename == "" {
+ // value, store as string in memory
+ n, err := io.Copyn(&b, p, maxValueBytes)
+ if err != nil && err != os.EOF {
+ return nil, err
+ }
+ maxValueBytes -= n
+ if maxValueBytes == 0 {
+ return nil, os.NewError("multipart: message too large")
+ }
+ form.Value[name] = append(form.Value[name], b.String())
+ continue
+ }
+
+ // file, store in memory or on disk
+ fh := &FileHeader{
+ Filename: filename,
+ Header: p.Header,
+ }
+ n, err := io.Copyn(&b, p, maxMemory+1)
+ if err != nil && err != os.EOF {
+ return nil, err
+ }
+ if n > maxMemory {
+ // too big, write to disk and flush buffer
+ file, err := ioutil.TempFile("", "multipart-")
+ if err != nil {
+ return nil, err
+ }
+ defer file.Close()
+ _, err = io.Copy(file, io.MultiReader(&b, p))
+ if err != nil {
+ os.Remove(file.Name())
+ return nil, err
+ }
+ fh.tmpfile = file.Name()
+ } else {
+ fh.content = b.Bytes()
+ maxMemory -= n
+ }
+ form.File[name] = append(form.File[name], fh)
+ }
+
+ return form, nil
+}
+
+// Form is a parsed multipart form.
+// Its File parts are stored either in memory or on disk,
+// and are accessible via the *FileHeader's Open method.
+// Its Value parts are stored as strings.
+// Both are keyed by field name.
+type Form struct {
+ Value map[string][]string
+ File map[string][]*FileHeader
+}
+
+// RemoveAll removes any temporary files associated with a Form.
+func (f *Form) RemoveAll() os.Error {
+ var err os.Error
+ for _, fhs := range f.File {
+ for _, fh := range fhs {
+ if fh.tmpfile != "" {
+ e := os.Remove(fh.tmpfile)
+ if e != nil && err == nil {
+ err = e
+ }
+ }
+ }
+ }
+ return err
+}
+
+// A FileHeader describes a file part of a multipart request.
+type FileHeader struct {
+ Filename string
+ Header textproto.MIMEHeader
+
+ content []byte
+ tmpfile string
+}
+
+// Open opens and returns the FileHeader's associated File.
+func (fh *FileHeader) Open() (File, os.Error) {
+ if b := fh.content; b != nil {
+ r := io.NewSectionReader(sliceReaderAt(b), 0, int64(len(b)))
+ return sectionReadCloser{r}, nil
+ }
+ return os.Open(fh.tmpfile)
+}
+
+// File is an interface to access the file part of a multipart message.
+// Its contents may be either stored in memory or on disk.
+// If stored on disk, the File's underlying concrete type will be an *os.File.
+type File interface {
+ io.Reader
+ io.ReaderAt
+ io.Seeker
+ io.Closer
+}
+
+// helper types to turn a []byte into a File
+
+type sectionReadCloser struct {
+ *io.SectionReader
+}
+
+func (rc sectionReadCloser) Close() os.Error {
+ return nil
+}
+
+type sliceReaderAt []byte
+
+func (r sliceReaderAt) ReadAt(b []byte, off int64) (int, os.Error) {
+ if int(off) >= len(r) || off < 0 {
+ return 0, os.EINVAL
+ }
+ n := copy(b, r[int(off):])
+ return n, nil
+}
--- /dev/null
+// Copyright 2011 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 multipart
+
+import (
+ "bytes"
+ "io"
+ "os"
+ "regexp"
+ "testing"
+)
+
+func TestReadForm(t *testing.T) {
+ testBody := regexp.MustCompile("\n").ReplaceAllString(message, "\r\n")
+ b := bytes.NewBufferString(testBody)
+ r := NewReader(b, boundary)
+ f, err := r.ReadForm(25)
+ if err != nil {
+ t.Fatal("ReadForm:", err)
+ }
+ defer f.RemoveAll()
+ if g, e := f.Value["texta"][0], textaValue; g != e {
+ t.Errorf("texta value = %q, want %q", g, e)
+ }
+ if g, e := f.Value["textb"][0], textbValue; g != e {
+ t.Errorf("texta value = %q, want %q", g, e)
+ }
+ fd := testFile(t, f.File["filea"][0], "filea.txt", fileaContents)
+ if _, ok := fd.(*os.File); ok {
+ t.Error("file is *os.File, should not be")
+ }
+ fd = testFile(t, f.File["fileb"][0], "fileb.txt", filebContents)
+ if _, ok := fd.(*os.File); !ok {
+ t.Error("file has unexpected underlying type %T", fd)
+ }
+}
+
+func testFile(t *testing.T, fh *FileHeader, efn, econtent string) File {
+ if fh.Filename != efn {
+ t.Errorf("filename = %q, want %q", fh.Filename, efn)
+ }
+ f, err := fh.Open()
+ if err != nil {
+ t.Fatal("opening file:", err)
+ }
+ b := new(bytes.Buffer)
+ _, err = io.Copy(b, f)
+ if err != nil {
+ t.Fatal("copying contents:", err)
+ }
+ if g := b.String(); g != econtent {
+ t.Errorf("contents = %q, want %q", g, econtent)
+ }
+ return f
+}
+
+const (
+ fileaContents = "This is a test file."
+ filebContents = "Another test file."
+ textaValue = "foo"
+ textbValue = "bar"
+ boundary = `MyBoundary`
+)
+
+const message = `
+--MyBoundary
+Content-Disposition: form-data; name="filea"; filename="filea.txt"
+Content-Type: text/plain
+
+` + fileaContents + `
+--MyBoundary
+Content-Disposition: form-data; name="fileb"; filename="fileb.txt"
+Content-Type: text/plain
+
+` + filebContents + `
+--MyBoundary
+Content-Disposition: form-data; name="texta"
+
+` + textaValue + `
+--MyBoundary
+Content-Disposition: form-data; name="textb"
+
+` + textbValue + `
+--MyBoundary--
+`
// reports errors, or on truncated or otherwise malformed
// input.
NextPart() (*Part, os.Error)
+
+ // ReadForm parses an entire multipart message whose parts have
+ // a Content-Disposition of "form-data".
+ // It stores up to maxMemory bytes of the file parts in memory
+ // and the remainder on disk in temporary files.
+ ReadForm(maxMemory int64) (*Form, os.Error)
}
// A Part represents a single part in a multipart body.
buffer *bytes.Buffer
mr *multiReader
+
+ dispositionParams map[string]string
}
// FormName returns the name parameter if p has a Content-Disposition
func (p *Part) FormName() string {
// See http://tools.ietf.org/html/rfc2183 section 2 for EBNF
// of Content-Disposition value format.
+ if p.dispositionParams != nil {
+ return p.dispositionParams["name"]
+ }
v := p.Header.Get("Content-Disposition")
if v == "" {
return ""
}
- d, params := mime.ParseMediaType(v)
- if d != "form-data" {
+ if d, params := mime.ParseMediaType(v); d != "form-data" {
return ""
+ } else {
+ p.dispositionParams = params
}
- return params["name"]
+ return p.dispositionParams["name"]
}
// NewReader creates a new multipart Reader reading from r using the