fix: reduce using memory and temporary files. (#17206)

cmd/api-errors.go

@@ -2189,10 +2189,10 @@ func toAPIErrorCode(ctx context.Context, err error) (apiErr APIErrorCode) {
 		apiErr = ErrContentSHA256Mismatch
 	case hash.ChecksumMismatch:
 		apiErr = ErrContentChecksumMismatch
-	case ObjectTooLarge:
-		apiErr = ErrEntityTooLarge
-	case ObjectTooSmall:
+	case hash.SizeTooSmall:
 		apiErr = ErrEntityTooSmall
+	case hash.SizeTooLarge:
+		apiErr = ErrEntityTooLarge
 	case NotImplemented:
 		apiErr = ErrNotImplemented
 	case PartTooBig:

cmd/bucket-handlers.go

@@ -22,8 +22,10 @@ import (
 	"context"
 	"encoding/base64"
 	"encoding/xml"
+	"errors"
 	"fmt"
 	"io"
+	"mime/multipart"
 	"net/http"
 	"net/textproto"
 	"net/url"
@@ -912,41 +914,111 @@ func (api objectAPIHandlers) PostPolicyBucketHandler(w http.ResponseWriter, r *h
 	reader, err := r.MultipartReader()
 	if err != nil {
 		apiErr := errorCodes.ToAPIErr(ErrMalformedPOSTRequest)
-		apiErr.Description = fmt.Sprintf("%s (%s)", apiErr.Description, err)
+		apiErr.Description = fmt.Sprintf("%s (%v)", apiErr.Description, err)
 		writeErrorResponse(ctx, w, apiErr, r.URL)
 		return
 	}
 
-	// Read multipart data and save in memory and in the disk if needed
-	form, err := reader.ReadForm(maxFormMemory)
-	if err != nil {
+	var (
+		fileBody io.ReadCloser
+		fileName string
+	)
+
+	maxParts := 1000
+	// Canonicalize the form values into http.Header.
+	formValues := make(http.Header)
+	for {
+		part, err := reader.NextRawPart()
+		if errors.Is(err, io.EOF) {
+			break
+		}
+		if err != nil {
+			apiErr := errorCodes.ToAPIErr(ErrMalformedPOSTRequest)
+			apiErr.Description = fmt.Sprintf("%s (%v)", apiErr.Description, err)
+			writeErrorResponse(ctx, w, apiErr, r.URL)
+			return
+		}
+		if maxParts <= 0 {
+			apiErr := errorCodes.ToAPIErr(ErrMalformedPOSTRequest)
+			apiErr.Description = fmt.Sprintf("%s (%v)", apiErr.Description, multipart.ErrMessageTooLarge)
+			writeErrorResponse(ctx, w, apiErr, r.URL)
+			return
+		}
+		maxParts--
+
+		name := part.FormName()
+		if name == "" {
+			continue
+		}
+
+		fileName = part.FileName()
+
+		// Multiple values for the same key (one map entry, longer slice) are cheaper
+		// than the same number of values for different keys (many map entries), but
+		// using a consistent per-value cost for overhead is simpler.
+		const mapEntryOverhead = 200
+		maxMemoryBytes := 2 * int64(10<<20)
+		maxMemoryBytes -= int64(len(name))
+		maxMemoryBytes -= mapEntryOverhead
+		if maxMemoryBytes < 0 {
+			// We can't actually take this path, since nextPart would already have
+			// rejected the MIME headers for being too large. Check anyway.
+			apiErr := errorCodes.ToAPIErr(ErrMalformedPOSTRequest)
+			apiErr.Description = fmt.Sprintf("%s (%v)", apiErr.Description, multipart.ErrMessageTooLarge)
+			writeErrorResponse(ctx, w, apiErr, r.URL)
+			return
+		}
+
+		var b bytes.Buffer
+		if fileName == "" {
+			// value, store as string in memory
+			n, err := io.CopyN(&b, part, maxMemoryBytes+1)
+			part.Close()
+			if err != nil && err != io.EOF {
+				apiErr := errorCodes.ToAPIErr(ErrMalformedPOSTRequest)
+				apiErr.Description = fmt.Sprintf("%s (%v)", apiErr.Description, err)
+				writeErrorResponse(ctx, w, apiErr, r.URL)
+				return
+			}
+			maxMemoryBytes -= n
+			if maxMemoryBytes < 0 {
+				apiErr := errorCodes.ToAPIErr(ErrMalformedPOSTRequest)
+				apiErr.Description = fmt.Sprintf("%s (%v)", apiErr.Description, multipart.ErrMessageTooLarge)
+				writeErrorResponse(ctx, w, apiErr, r.URL)
+				return
+			}
+			if n > maxFormFieldSize {
+				apiErr := errorCodes.ToAPIErr(ErrMalformedPOSTRequest)
+				apiErr.Description = fmt.Sprintf("%s (%v)", apiErr.Description, multipart.ErrMessageTooLarge)
+				writeErrorResponse(ctx, w, apiErr, r.URL)
+				return
+			}
+			formValues[http.CanonicalHeaderKey(name)] = append(formValues[http.CanonicalHeaderKey(name)], b.String())
+			continue
+		}
+
+		// In accordance with https://docs.aws.amazon.com/AmazonS3/latest/API/RESTObjectPOST.html
+		// The file or text content.
+		// The file or text content must be the last field in the form.
+		// You cannot upload more than one file at a time.
+		fileBody = part // we have found the File part of the request breakout
+		defer part.Close()
+		break
+	}
+
+	if _, ok := formValues["Key"]; !ok {
 		apiErr := errorCodes.ToAPIErr(ErrMalformedPOSTRequest)
-		apiErr.Description = fmt.Sprintf("%s (%s)", apiErr.Description, err)
+		apiErr.Description = fmt.Sprintf("%s (%v)", apiErr.Description, errors.New("The name of the uploaded key is missing"))
 		writeErrorResponse(ctx, w, apiErr, r.URL)
 		return
 	}
-
-	// Remove all tmp files created during multipart upload
-	defer form.RemoveAll()
-
-	// Extract all form fields
-	fileBody, fileName, fileSize, formValues, err := extractPostPolicyFormValues(ctx, form)
-	if err != nil {
+	if fileName == "" {
 		apiErr := errorCodes.ToAPIErr(ErrMalformedPOSTRequest)
-		apiErr.Description = fmt.Sprintf("%s (%s)", apiErr.Description, err)
+		apiErr.Description = fmt.Sprintf("%s (%v)", apiErr.Description, errors.New("The file or text content is missing"))
 		writeErrorResponse(ctx, w, apiErr, r.URL)
 		return
 	}
 
-	// Check if file is provided, error out otherwise.
-	if fileBody == nil {
-		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrPOSTFileRequired), r.URL)
-		return
-	}
-
-	// Close multipart file
-	defer fileBody.Close()
-
 	formValues.Set("Bucket", bucket)
 	if fileName != "" && strings.Contains(formValues.Get("Key"), "${filename}") {
 		// S3 feature to replace ${filename} found in Key form field
@@ -995,6 +1067,13 @@ func (api objectAPIHandlers) PostPolicyBucketHandler(w http.ResponseWriter, r *h
 		return
 	}
 
+	hashReader, err := hash.NewReader(fileBody, -1, "", "", -1)
+	if err != nil {
+		logger.LogIf(ctx, err)
+		writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
+		return
+	}
+
 	// Handle policy if it is set.
 	if len(policyBytes) > 0 {
 		postPolicyForm, err := parsePostPolicyForm(bytes.NewReader(policyBytes))
@@ -1015,15 +1094,8 @@ func (api objectAPIHandlers) PostPolicyBucketHandler(w http.ResponseWriter, r *h
 		// should not exceed the maximum single Put size (5 GiB)
 		lengthRange := postPolicyForm.Conditions.ContentLengthRange
 		if lengthRange.Valid {
-			if fileSize < lengthRange.Min {
-				writeErrorResponse(ctx, w, toAPIError(ctx, errDataTooSmall), r.URL)
-				return
-			}
-
-			if fileSize > lengthRange.Max || isMaxObjectSize(fileSize) {
-				writeErrorResponse(ctx, w, toAPIError(ctx, errDataTooLarge), r.URL)
-				return
-			}
+			hashReader.SetExpectedMin(lengthRange.Min)
+			hashReader.SetExpectedMax(lengthRange.Max)
 		}
 	}
 
@@ -1035,12 +1107,6 @@ func (api objectAPIHandlers) PostPolicyBucketHandler(w http.ResponseWriter, r *h
 		return
 	}
 
-	hashReader, err := hash.NewReader(fileBody, fileSize, "", "", fileSize)
-	if err != nil {
-		logger.LogIf(ctx, err)
-		writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
-		return
-	}
 	rawReader := hashReader
 	pReader := NewPutObjReader(rawReader)
 	var objectEncryptionKey crypto.ObjectKey
@@ -1095,9 +1161,8 @@ func (api objectAPIHandlers) PostPolicyBucketHandler(w http.ResponseWriter, r *h
 			writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
 			return
 		}
-		info := ObjectInfo{Size: fileSize}
-		// do not try to verify encrypted content
-		hashReader, err = hash.NewReader(reader, info.EncryptedSize(), "", "", fileSize)
+		// do not try to verify encrypted content/
+		hashReader, err = hash.NewReader(reader, -1, "", "", -1)
 		if err != nil {
 			writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
 			return

cmd/globals.go

@@ -89,9 +89,6 @@ const (
 	// can reach that size according to https://aws.amazon.com/articles/1434
 	maxFormFieldSize = int64(1 * humanize.MiByte)
 
-	// Limit memory allocation to store multipart data
-	maxFormMemory = int64(5 * humanize.MiByte)
-
 	// The maximum allowed time difference between the incoming request
 	// date and server date during signature verification.
 	globalMaxSkewTime = 15 * time.Minute // 15 minutes skew allowed.

cmd/handler-utils.go

@@ -18,12 +18,9 @@
 package cmd
 
 import (
-	"bytes"
 	"context"
 	"errors"
 	"fmt"
-	"io"
-	"mime/multipart"
 	"net/http"
 	"net/textproto"
 	"regexp"
@@ -270,87 +267,6 @@ func trimAwsChunkedContentEncoding(contentEnc string) (trimmedContentEnc string)
 	return strings.Join(newEncs, ",")
 }
 
-// Validate form field size for s3 specification requirement.
-func validateFormFieldSize(ctx context.Context, formValues http.Header) error {
-	// Iterate over form values
-	for k := range formValues {
-		// Check if value's field exceeds S3 limit
-		if int64(len(formValues.Get(k))) > maxFormFieldSize {
-			logger.LogIf(ctx, errSizeUnexpected)
-			return errSizeUnexpected
-		}
-	}
-
-	// Success.
-	return nil
-}
-
-// Extract form fields and file data from a HTTP POST Policy
-func extractPostPolicyFormValues(ctx context.Context, form *multipart.Form) (filePart io.ReadCloser, fileName string, fileSize int64, formValues http.Header, err error) {
-	// HTML Form values
-	fileName = ""
-
-	// Canonicalize the form values into http.Header.
-	formValues = make(http.Header)
-	for k, v := range form.Value {
-		formValues[http.CanonicalHeaderKey(k)] = v
-	}
-
-	// Validate form values.
-	if err = validateFormFieldSize(ctx, formValues); err != nil {
-		return nil, "", 0, nil, err
-	}
-
-	// this means that filename="" was not specified for file key and Go has
-	// an ugly way of handling this situation. Refer here
-	// https://golang.org/src/mime/multipart/formdata.go#L61
-	if len(form.File) == 0 {
-		b := &bytes.Buffer{}
-		for _, v := range formValues["File"] {
-			b.WriteString(v)
-		}
-		fileSize = int64(b.Len())
-		filePart = io.NopCloser(b)
-		return filePart, fileName, fileSize, formValues, nil
-	}
-
-	// Iterator until we find a valid File field and break
-	for k, v := range form.File {
-		canonicalFormName := http.CanonicalHeaderKey(k)
-		if canonicalFormName == "File" {
-			if len(v) == 0 {
-				logger.LogIf(ctx, errInvalidArgument)
-				return nil, "", 0, nil, errInvalidArgument
-			}
-			// Fetch fileHeader which has the uploaded file information
-			fileHeader := v[0]
-			// Set filename
-			fileName = fileHeader.Filename
-			// Open the uploaded part
-			filePart, err = fileHeader.Open()
-			if err != nil {
-				logger.LogIf(ctx, err)
-				return nil, "", 0, nil, err
-			}
-			// Compute file size
-			fileSize, err = filePart.(io.Seeker).Seek(0, 2)
-			if err != nil {
-				logger.LogIf(ctx, err)
-				return nil, "", 0, nil, err
-			}
-			// Reset Seek to the beginning
-			_, err = filePart.(io.Seeker).Seek(0, 0)
-			if err != nil {
-				logger.LogIf(ctx, err)
-				return nil, "", 0, nil, err
-			}
-			// File found and ready for reading
-			break
-		}
-	}
-	return filePart, fileName, fileSize, formValues, nil
-}
-
 func collectAPIStats(api string, f http.HandlerFunc) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		globalHTTPStats.currentS3Requests.Inc(api)

cmd/handler-utils_test.go

@@ -26,7 +26,6 @@ import (
 	"net/textproto"
 	"os"
 	"reflect"
-	"strings"
 	"testing"
 
 	"github.com/minio/minio/internal/config"
@@ -96,44 +95,6 @@ func TestIsValidLocationContraint(t *testing.T) {
 	}
 }
 
-// Test validate form field size.
-func TestValidateFormFieldSize(t *testing.T) {
-	testCases := []struct {
-		header http.Header
-		err    error
-	}{
-		// Empty header returns error as nil,
-		{
-			header: nil,
-			err:    nil,
-		},
-		// Valid header returns error as nil.
-		{
-			header: http.Header{
-				"Content-Type": []string{"image/png"},
-			},
-			err: nil,
-		},
-		// Invalid header value > maxFormFieldSize+1
-		{
-			header: http.Header{
-				"Garbage": []string{strings.Repeat("a", int(maxFormFieldSize)+1)},
-			},
-			err: errSizeUnexpected,
-		},
-	}
-
-	// Run validate form field size check under all test cases.
-	for i, testCase := range testCases {
-		err := validateFormFieldSize(context.Background(), testCase.header)
-		if err != nil {
-			if err.Error() != testCase.err.Error() {
-				t.Errorf("Test %d: Expected error %s, got %s", i+1, testCase.err, err)
-			}
-		}
-	}
-}
-
 // Tests validate metadata extraction from http headers.
 func TestExtractMetadataHeaders(t *testing.T) {
 	testCases := []struct {

cmd/typed-errors.go

@@ -30,9 +30,6 @@ var errMethodNotAllowed = errors.New("Method not allowed")
 // errSignatureMismatch means signature did not match.
 var errSignatureMismatch = errors.New("Signature does not match")
 
-// used when we deal with data larger than expected
-var errSizeUnexpected = errors.New("Data size larger than expected")
-
 // When upload object size is greater than 5G in a single PUT/POST operation.
 var errDataTooLarge = errors.New("Object size larger than allowed limit")