server: Move all the top level files into cmd folder. (#2490)

This change brings a change which was done for the 'mc'
package to allow for clean repo and have a cleaner
github drop in experience.

cmd/object-handlers.go

@@ -0,0 +1,867 @@
+/*
+ * Minio Cloud Storage, (C) 2015 Minio, Inc.
+ *
+ * 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 cmd
+
+import (
+	"encoding/hex"
+	"encoding/xml"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"path"
+	"sort"
+	"strconv"
+	"strings"
+
+	mux "github.com/gorilla/mux"
+)
+
+// supportedGetReqParams - supported request parameters for GET presigned request.
+var supportedGetReqParams = map[string]string{
+	"response-expires":             "Expires",
+	"response-content-type":        "Content-Type",
+	"response-cache-control":       "Cache-Control",
+	"response-content-encoding":    "Content-Encoding",
+	"response-content-language":    "Content-Language",
+	"response-content-disposition": "Content-Disposition",
+}
+
+// setGetRespHeaders - set any requested parameters as response headers.
+func setGetRespHeaders(w http.ResponseWriter, reqParams url.Values) {
+	for k, v := range reqParams {
+		if header, ok := supportedGetReqParams[k]; ok {
+			w.Header()[header] = v
+		}
+	}
+}
+
+// errAllowableNotFound - For an anon user, return 404 if have ListBucket, 403 otherwise
+// this is in keeping with the permissions sections of the docs of both:
+//   HEAD Object: http://docs.aws.amazon.com/AmazonS3/latest/API/RESTObjectHEAD.html
+//   GET Object: http://docs.aws.amazon.com/AmazonS3/latest/API/RESTObjectGET.html
+func errAllowableObjectNotFound(bucket string, r *http.Request) APIErrorCode {
+	if getRequestAuthType(r) == authTypeAnonymous {
+		//we care about the bucket as a whole, not a particular resource
+		url := *r.URL
+		url.Path = "/" + bucket
+
+		if s3Error := enforceBucketPolicy(bucket, "s3:ListBucket", &url); s3Error != ErrNone {
+			return ErrAccessDenied
+		}
+	}
+	return ErrNoSuchKey
+}
+
+// Simple way to convert a func to io.Writer type.
+type funcToWriter func([]byte) (int, error)
+
+func (f funcToWriter) Write(p []byte) (int, error) {
+	return f(p)
+}
+
+// GetObjectHandler - GET Object
+// ----------
+// This implementation of the GET operation retrieves object. To use GET,
+// you must have READ access to the object.
+func (api objectAPIHandlers) GetObjectHandler(w http.ResponseWriter, r *http.Request) {
+	var object, bucket string
+	vars := mux.Vars(r)
+	bucket = vars["bucket"]
+	object = vars["object"]
+
+	switch getRequestAuthType(r) {
+	default:
+		// For all unknown auth types return error.
+		writeErrorResponse(w, r, ErrAccessDenied, r.URL.Path)
+		return
+	case authTypeAnonymous:
+		// http://docs.aws.amazon.com/AmazonS3/latest/dev/using-with-s3-actions.html
+		if s3Error := enforceBucketPolicy(bucket, "s3:GetObject", r.URL); s3Error != ErrNone {
+			writeErrorResponse(w, r, s3Error, r.URL.Path)
+			return
+		}
+	case authTypePresigned, authTypeSigned:
+		if s3Error := isReqAuthenticated(r); s3Error != ErrNone {
+			writeErrorResponse(w, r, s3Error, r.URL.Path)
+			return
+		}
+	}
+	// Fetch object stat info.
+	objInfo, err := api.ObjectAPI.GetObjectInfo(bucket, object)
+	if err != nil {
+		errorIf(err, "Unable to fetch object info.")
+		apiErr := toAPIErrorCode(err)
+		if apiErr == ErrNoSuchKey {
+			apiErr = errAllowableObjectNotFound(bucket, r)
+		}
+		writeErrorResponse(w, r, apiErr, r.URL.Path)
+		return
+	}
+
+	// Get request range.
+	var hrange *httpRange
+	rangeHeader := r.Header.Get("Range")
+	if rangeHeader != "" {
+		if hrange, err = parseRequestRange(rangeHeader, objInfo.Size); err != nil {
+			// Handle only errInvalidRange
+			// Ignore other parse error and treat it as regular Get request like Amazon S3.
+			if err == errInvalidRange {
+				writeErrorResponse(w, r, ErrInvalidRange, r.URL.Path)
+				return
+			}
+
+			// log the error.
+			errorIf(err, "Invalid request range")
+		}
+
+	}
+
+	// Validate pre-conditions if any.
+	if checkPreconditions(w, r, objInfo) {
+		return
+	}
+
+	// Get the object.
+	startOffset := int64(0)
+	length := objInfo.Size
+	if hrange != nil {
+		startOffset = hrange.offsetBegin
+		length = hrange.getLength()
+	}
+	// Indicates if any data was written to the http.ResponseWriter
+	dataWritten := false
+	// io.Writer type which keeps track if any data was written.
+	writer := funcToWriter(func(p []byte) (int, error) {
+		if !dataWritten {
+			// Set headers on the first write.
+			// Set standard object headers.
+			setObjectHeaders(w, objInfo, hrange)
+
+			// Set any additional requested response headers.
+			setGetRespHeaders(w, r.URL.Query())
+
+			dataWritten = true
+		}
+		return w.Write(p)
+	})
+
+	// Reads the object at startOffset and writes to mw.
+	if err := api.ObjectAPI.GetObject(bucket, object, startOffset, length, writer); err != nil {
+		errorIf(err, "Unable to write to client.")
+		if !dataWritten {
+			// Error response only if no data has been written to client yet. i.e if
+			// partial data has already been written before an error
+			// occurred then no point in setting StatusCode and
+			// sending error XML.
+			apiErr := toAPIErrorCode(err)
+			writeErrorResponse(w, r, apiErr, r.URL.Path)
+		}
+		return
+	}
+	if !dataWritten {
+		// If ObjectAPI.GetObject did not return error and no data has
+		// been written it would mean that it is a 0-byte object.
+		// call wrter.Write(nil) to set appropriate headers.
+		writer.Write(nil)
+	}
+}
+
+// HeadObjectHandler - HEAD Object
+// -----------
+// The HEAD operation retrieves metadata from an object without returning the object itself.
+func (api objectAPIHandlers) HeadObjectHandler(w http.ResponseWriter, r *http.Request) {
+	var object, bucket string
+	vars := mux.Vars(r)
+	bucket = vars["bucket"]
+	object = vars["object"]
+
+	switch getRequestAuthType(r) {
+	default:
+		// For all unknown auth types return error.
+		writeErrorResponse(w, r, ErrAccessDenied, r.URL.Path)
+		return
+	case authTypeAnonymous:
+		// http://docs.aws.amazon.com/AmazonS3/latest/dev/using-with-s3-actions.html
+		if s3Error := enforceBucketPolicy(bucket, "s3:GetObject", r.URL); s3Error != ErrNone {
+			writeErrorResponse(w, r, s3Error, r.URL.Path)
+			return
+		}
+	case authTypePresigned, authTypeSigned:
+		if s3Error := isReqAuthenticated(r); s3Error != ErrNone {
+			writeErrorResponse(w, r, s3Error, r.URL.Path)
+			return
+		}
+	}
+
+	objInfo, err := api.ObjectAPI.GetObjectInfo(bucket, object)
+	if err != nil {
+		errorIf(err, "Unable to fetch object info.")
+		apiErr := toAPIErrorCode(err)
+		if apiErr == ErrNoSuchKey {
+			apiErr = errAllowableObjectNotFound(bucket, r)
+		}
+		writeErrorResponse(w, r, apiErr, r.URL.Path)
+		return
+	}
+
+	// Validate pre-conditions if any.
+	if checkPreconditions(w, r, objInfo) {
+		return
+	}
+
+	// Set standard object headers.
+	setObjectHeaders(w, objInfo, nil)
+
+	// Successful response.
+	w.WriteHeader(http.StatusOK)
+}
+
+// CopyObjectHandler - Copy Object
+// ----------
+// This implementation of the PUT operation adds an object to a bucket
+// while reading the object from another source.
+func (api objectAPIHandlers) CopyObjectHandler(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	bucket := vars["bucket"]
+	object := vars["object"]
+
+	switch getRequestAuthType(r) {
+	default:
+		// For all unknown auth types return error.
+		writeErrorResponse(w, r, ErrAccessDenied, r.URL.Path)
+		return
+	case authTypeAnonymous:
+		// http://docs.aws.amazon.com/AmazonS3/latest/dev/using-with-s3-actions.html
+		if s3Error := enforceBucketPolicy(bucket, "s3:PutObject", r.URL); s3Error != ErrNone {
+			writeErrorResponse(w, r, s3Error, r.URL.Path)
+			return
+		}
+	case authTypePresigned, authTypeSigned:
+		if s3Error := isReqAuthenticated(r); s3Error != ErrNone {
+			writeErrorResponse(w, r, s3Error, r.URL.Path)
+			return
+		}
+	}
+
+	// TODO: Reject requests where body/payload is present, for now we don't even read it.
+
+	// objectSource
+	objectSource, err := url.QueryUnescape(r.Header.Get("X-Amz-Copy-Source"))
+	if err != nil {
+		// Save unescaped string as is.
+		objectSource = r.Header.Get("X-Amz-Copy-Source")
+	}
+
+	// Skip the first element if it is '/', split the rest.
+	if strings.HasPrefix(objectSource, "/") {
+		objectSource = objectSource[1:]
+	}
+	splits := strings.SplitN(objectSource, "/", 2)
+
+	// Save sourceBucket and sourceObject extracted from url Path.
+	var sourceBucket, sourceObject string
+	if len(splits) == 2 {
+		sourceBucket = splits[0]
+		sourceObject = splits[1]
+	}
+	// If source object is empty, reply back error.
+	if sourceObject == "" {
+		writeErrorResponse(w, r, ErrInvalidCopySource, r.URL.Path)
+		return
+	}
+
+	// Source and destination objects cannot be same, reply back error.
+	if sourceObject == object && sourceBucket == bucket {
+		writeErrorResponse(w, r, ErrInvalidCopyDest, r.URL.Path)
+		return
+	}
+
+	objInfo, err := api.ObjectAPI.GetObjectInfo(sourceBucket, sourceObject)
+	if err != nil {
+		errorIf(err, "Unable to fetch object info.")
+		writeErrorResponse(w, r, toAPIErrorCode(err), objectSource)
+		return
+	}
+
+	// Verify before x-amz-copy-source preconditions before continuing with CopyObject.
+	if checkCopyObjectPreconditions(w, r, objInfo) {
+		return
+	}
+
+	/// maximum Upload size for object in a single CopyObject operation.
+	if isMaxObjectSize(objInfo.Size) {
+		writeErrorResponse(w, r, ErrEntityTooLarge, objectSource)
+		return
+	}
+
+	pipeReader, pipeWriter := io.Pipe()
+	go func() {
+		startOffset := int64(0) // Read the whole file.
+		// Get the object.
+		gErr := api.ObjectAPI.GetObject(sourceBucket, sourceObject, startOffset, objInfo.Size, pipeWriter)
+		if gErr != nil {
+			errorIf(gErr, "Unable to read an object.")
+			pipeWriter.CloseWithError(gErr)
+			return
+		}
+		pipeWriter.Close() // Close.
+	}()
+
+	// Size of object.
+	size := objInfo.Size
+
+	// Save metadata.
+	metadata := make(map[string]string)
+	// Save other metadata if available.
+	metadata = objInfo.UserDefined
+
+	// Do not set `md5sum` as CopyObject will not keep the
+	// same md5sum as the source.
+
+	// Create the object.
+	md5Sum, err := api.ObjectAPI.PutObject(bucket, object, size, pipeReader, metadata)
+	if err != nil {
+		errorIf(err, "Unable to create an object.")
+		writeErrorResponse(w, r, toAPIErrorCode(err), r.URL.Path)
+		return
+	}
+
+	objInfo, err = api.ObjectAPI.GetObjectInfo(bucket, object)
+	if err != nil {
+		errorIf(err, "Unable to fetch object info.")
+		writeErrorResponse(w, r, toAPIErrorCode(err), r.URL.Path)
+		return
+	}
+
+	response := generateCopyObjectResponse(md5Sum, objInfo.ModTime)
+	encodedSuccessResponse := encodeResponse(response)
+	// write headers
+	setCommonHeaders(w)
+	// write success response.
+	writeSuccessResponse(w, encodedSuccessResponse)
+	// Explicitly close the reader, to avoid fd leaks.
+	pipeReader.Close()
+
+	if eventN.IsBucketNotificationSet(bucket) {
+		// Notify object created event.
+		eventNotify(eventData{
+			Type:    ObjectCreatedCopy,
+			Bucket:  bucket,
+			ObjInfo: objInfo,
+			ReqParams: map[string]string{
+				"sourceIPAddress": r.RemoteAddr,
+			},
+		})
+	}
+}
+
+// PutObjectHandler - PUT Object
+// ----------
+// This implementation of the PUT operation adds an object to a bucket.
+func (api objectAPIHandlers) PutObjectHandler(w http.ResponseWriter, r *http.Request) {
+	// If the matching failed, it means that the X-Amz-Copy-Source was
+	// wrong, fail right here.
+	if _, ok := r.Header["X-Amz-Copy-Source"]; ok {
+		writeErrorResponse(w, r, ErrInvalidCopySource, r.URL.Path)
+		return
+	}
+	vars := mux.Vars(r)
+	bucket := vars["bucket"]
+	object := vars["object"]
+
+	// Get Content-Md5 sent by client and verify if valid
+	md5Bytes, err := checkValidMD5(r.Header.Get("Content-Md5"))
+	if err != nil {
+		errorIf(err, "Unable to validate content-md5 format.")
+		writeErrorResponse(w, r, ErrInvalidDigest, r.URL.Path)
+		return
+	}
+	/// if Content-Length is unknown/missing, deny the request
+	size := r.ContentLength
+	rAuthType := getRequestAuthType(r)
+	if rAuthType == authTypeStreamingSigned {
+		sizeStr := r.Header.Get("x-amz-decoded-content-length")
+		size, err = strconv.ParseInt(sizeStr, 10, 64)
+		if err != nil {
+			errorIf(err, "Unable to parse `x-amz-decoded-content-length` into its integer value", sizeStr)
+			writeErrorResponse(w, r, toAPIErrorCode(err), r.URL.Path)
+			return
+		}
+	}
+	if size == -1 && !contains(r.TransferEncoding, "chunked") {
+		writeErrorResponse(w, r, ErrMissingContentLength, r.URL.Path)
+		return
+	}
+	/// maximum Upload size for objects in a single operation
+	if isMaxObjectSize(size) {
+		writeErrorResponse(w, r, ErrEntityTooLarge, r.URL.Path)
+		return
+	}
+
+	// Extract metadata to be saved from incoming HTTP header.
+	metadata := extractMetadataFromHeader(r.Header)
+	// Make sure we hex encode md5sum here.
+	metadata["md5Sum"] = hex.EncodeToString(md5Bytes)
+
+	var md5Sum string
+	switch rAuthType {
+	default:
+		// For all unknown auth types return error.
+		writeErrorResponse(w, r, ErrAccessDenied, r.URL.Path)
+		return
+	case authTypeAnonymous:
+		// http://docs.aws.amazon.com/AmazonS3/latest/dev/using-with-s3-actions.html
+		if s3Error := enforceBucketPolicy(bucket, "s3:PutObject", r.URL); s3Error != ErrNone {
+			writeErrorResponse(w, r, s3Error, r.URL.Path)
+			return
+		}
+		// Create anonymous object.
+		md5Sum, err = api.ObjectAPI.PutObject(bucket, object, size, r.Body, metadata)
+	case authTypeStreamingSigned:
+		// Initialize stream signature verifier.
+		reader, s3Error := newSignV4ChunkedReader(r)
+		if s3Error != ErrNone {
+			writeErrorResponse(w, r, s3Error, r.URL.Path)
+			return
+		}
+		md5Sum, err = api.ObjectAPI.PutObject(bucket, object, size, reader, metadata)
+	case authTypePresigned, authTypeSigned:
+		// Initialize signature verifier.
+		reader := newSignVerify(r)
+		// Create object.
+		md5Sum, err = api.ObjectAPI.PutObject(bucket, object, size, reader, metadata)
+	}
+	if err != nil {
+		errorIf(err, "Unable to create an object.")
+		writeErrorResponse(w, r, toAPIErrorCode(err), r.URL.Path)
+		return
+	}
+	if md5Sum != "" {
+		w.Header().Set("ETag", "\""+md5Sum+"\"")
+	}
+	writeSuccessResponse(w, nil)
+
+	// Fetch object info for notifications.
+	objInfo, err := api.ObjectAPI.GetObjectInfo(bucket, object)
+	if err != nil {
+		errorIf(err, "Unable to fetch object info for \"%s\"", path.Join(bucket, object))
+		return
+	}
+
+	if eventN.IsBucketNotificationSet(bucket) {
+		// Notify object created event.
+		eventNotify(eventData{
+			Type:    ObjectCreatedPut,
+			Bucket:  bucket,
+			ObjInfo: objInfo,
+			ReqParams: map[string]string{
+				"sourceIPAddress": r.RemoteAddr,
+			},
+		})
+	}
+}
+
+/// Multipart objectAPIHandlers
+
+// NewMultipartUploadHandler - New multipart upload
+func (api objectAPIHandlers) NewMultipartUploadHandler(w http.ResponseWriter, r *http.Request) {
+	var object, bucket string
+	vars := mux.Vars(r)
+	bucket = vars["bucket"]
+	object = vars["object"]
+
+	switch getRequestAuthType(r) {
+	default:
+		// For all unknown auth types return error.
+		writeErrorResponse(w, r, ErrAccessDenied, r.URL.Path)
+		return
+	case authTypeAnonymous:
+		// http://docs.aws.amazon.com/AmazonS3/latest/dev/mpuAndPermissions.html
+		if s3Error := enforceBucketPolicy(bucket, "s3:PutObject", r.URL); s3Error != ErrNone {
+			writeErrorResponse(w, r, s3Error, r.URL.Path)
+			return
+		}
+	case authTypePresigned, authTypeSigned:
+		if s3Error := isReqAuthenticated(r); s3Error != ErrNone {
+			writeErrorResponse(w, r, s3Error, r.URL.Path)
+			return
+		}
+	}
+
+	// Extract metadata that needs to be saved.
+	metadata := extractMetadataFromHeader(r.Header)
+
+	uploadID, err := api.ObjectAPI.NewMultipartUpload(bucket, object, metadata)
+	if err != nil {
+		errorIf(err, "Unable to initiate new multipart upload id.")
+		writeErrorResponse(w, r, toAPIErrorCode(err), r.URL.Path)
+		return
+	}
+
+	response := generateInitiateMultipartUploadResponse(bucket, object, uploadID)
+	encodedSuccessResponse := encodeResponse(response)
+	// write headers
+	setCommonHeaders(w)
+	// write success response.
+	writeSuccessResponse(w, encodedSuccessResponse)
+}
+
+// PutObjectPartHandler - Upload part
+func (api objectAPIHandlers) PutObjectPartHandler(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	bucket := vars["bucket"]
+	object := vars["object"]
+
+	// get Content-Md5 sent by client and verify if valid
+	md5Bytes, err := checkValidMD5(r.Header.Get("Content-Md5"))
+	if err != nil {
+		writeErrorResponse(w, r, ErrInvalidDigest, r.URL.Path)
+		return
+	}
+
+	/// if Content-Length is unknown/missing, throw away
+	size := r.ContentLength
+
+	rAuthType := getRequestAuthType(r)
+	// For auth type streaming signature, we need to gather a different content length.
+	if rAuthType == authTypeStreamingSigned {
+		sizeStr := r.Header.Get("x-amz-decoded-content-length")
+		size, err = strconv.ParseInt(sizeStr, 10, 64)
+		if err != nil {
+			errorIf(err, "Unable to parse `x-amz-decoded-content-length` into its integer value", sizeStr)
+			writeErrorResponse(w, r, toAPIErrorCode(err), r.URL.Path)
+			return
+		}
+	}
+	if size == -1 {
+		writeErrorResponse(w, r, ErrMissingContentLength, r.URL.Path)
+		return
+	}
+
+	/// maximum Upload size for multipart objects in a single operation
+	if isMaxObjectSize(size) {
+		writeErrorResponse(w, r, ErrEntityTooLarge, r.URL.Path)
+		return
+	}
+
+	uploadID := r.URL.Query().Get("uploadId")
+	partIDString := r.URL.Query().Get("partNumber")
+
+	partID, err := strconv.Atoi(partIDString)
+	if err != nil {
+		writeErrorResponse(w, r, ErrInvalidPart, r.URL.Path)
+		return
+	}
+
+	// check partID with maximum part ID for multipart objects
+	if isMaxPartID(partID) {
+		writeErrorResponse(w, r, ErrInvalidMaxParts, r.URL.Path)
+		return
+	}
+
+	var partMD5 string
+	incomingMD5 := hex.EncodeToString(md5Bytes)
+	switch rAuthType {
+	default:
+		// For all unknown auth types return error.
+		writeErrorResponse(w, r, ErrAccessDenied, r.URL.Path)
+		return
+	case authTypeAnonymous:
+		// http://docs.aws.amazon.com/AmazonS3/latest/dev/mpuAndPermissions.html
+		if s3Error := enforceBucketPolicy(bucket, "s3:PutObject", r.URL); s3Error != ErrNone {
+			writeErrorResponse(w, r, s3Error, r.URL.Path)
+			return
+		}
+		// No need to verify signature, anonymous request access is already allowed.
+		partMD5, err = api.ObjectAPI.PutObjectPart(bucket, object, uploadID, partID, size, r.Body, incomingMD5)
+	case authTypeStreamingSigned:
+		// Initialize stream signature verifier.
+		reader, s3Error := newSignV4ChunkedReader(r)
+		if s3Error != ErrNone {
+			writeErrorResponse(w, r, s3Error, r.URL.Path)
+			return
+		}
+		partMD5, err = api.ObjectAPI.PutObjectPart(bucket, object, uploadID, partID, size, reader, incomingMD5)
+	case authTypePresigned, authTypeSigned:
+		// Initialize signature verifier.
+		reader := newSignVerify(r)
+		partMD5, err = api.ObjectAPI.PutObjectPart(bucket, object, uploadID, partID, size, reader, incomingMD5)
+	}
+	if err != nil {
+		errorIf(err, "Unable to create object part.")
+		// Verify if the underlying error is signature mismatch.
+		writeErrorResponse(w, r, toAPIErrorCode(err), r.URL.Path)
+		return
+	}
+	if partMD5 != "" {
+		w.Header().Set("ETag", "\""+partMD5+"\"")
+	}
+	writeSuccessResponse(w, nil)
+}
+
+// AbortMultipartUploadHandler - Abort multipart upload
+func (api objectAPIHandlers) AbortMultipartUploadHandler(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	bucket := vars["bucket"]
+	object := vars["object"]
+
+	switch getRequestAuthType(r) {
+	default:
+		// For all unknown auth types return error.
+		writeErrorResponse(w, r, ErrAccessDenied, r.URL.Path)
+		return
+	case authTypeAnonymous:
+		// http://docs.aws.amazon.com/AmazonS3/latest/dev/mpuAndPermissions.html
+		if s3Error := enforceBucketPolicy(bucket, "s3:AbortMultipartUpload", r.URL); s3Error != ErrNone {
+			writeErrorResponse(w, r, s3Error, r.URL.Path)
+			return
+		}
+	case authTypePresigned, authTypeSigned:
+		if s3Error := isReqAuthenticated(r); s3Error != ErrNone {
+			writeErrorResponse(w, r, s3Error, r.URL.Path)
+			return
+		}
+	}
+
+	uploadID, _, _, _ := getObjectResources(r.URL.Query())
+	if err := api.ObjectAPI.AbortMultipartUpload(bucket, object, uploadID); err != nil {
+		errorIf(err, "Unable to abort multipart upload.")
+		writeErrorResponse(w, r, toAPIErrorCode(err), r.URL.Path)
+		return
+	}
+	writeSuccessNoContent(w)
+}
+
+// ListObjectPartsHandler - List object parts
+func (api objectAPIHandlers) ListObjectPartsHandler(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	bucket := vars["bucket"]
+	object := vars["object"]
+
+	switch getRequestAuthType(r) {
+	default:
+		// For all unknown auth types return error.
+		writeErrorResponse(w, r, ErrAccessDenied, r.URL.Path)
+		return
+	case authTypeAnonymous:
+		// http://docs.aws.amazon.com/AmazonS3/latest/dev/mpuAndPermissions.html
+		if s3Error := enforceBucketPolicy(bucket, "s3:ListMultipartUploadParts", r.URL); s3Error != ErrNone {
+			writeErrorResponse(w, r, s3Error, r.URL.Path)
+			return
+		}
+	case authTypePresigned, authTypeSigned:
+		if s3Error := isReqAuthenticated(r); s3Error != ErrNone {
+			writeErrorResponse(w, r, s3Error, r.URL.Path)
+			return
+		}
+	}
+
+	uploadID, partNumberMarker, maxParts, _ := getObjectResources(r.URL.Query())
+	if partNumberMarker < 0 {
+		writeErrorResponse(w, r, ErrInvalidPartNumberMarker, r.URL.Path)
+		return
+	}
+	if maxParts < 0 {
+		writeErrorResponse(w, r, ErrInvalidMaxParts, r.URL.Path)
+		return
+	}
+	listPartsInfo, err := api.ObjectAPI.ListObjectParts(bucket, object, uploadID, partNumberMarker, maxParts)
+	if err != nil {
+		errorIf(err, "Unable to list uploaded parts.")
+		writeErrorResponse(w, r, toAPIErrorCode(err), r.URL.Path)
+		return
+	}
+	response := generateListPartsResponse(listPartsInfo)
+	encodedSuccessResponse := encodeResponse(response)
+	// Write headers.
+	setCommonHeaders(w)
+	// Write success response.
+	writeSuccessResponse(w, encodedSuccessResponse)
+}
+
+// CompleteMultipartUploadHandler - Complete multipart upload
+func (api objectAPIHandlers) CompleteMultipartUploadHandler(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	bucket := vars["bucket"]
+	object := vars["object"]
+
+	// Get upload id.
+	uploadID, _, _, _ := getObjectResources(r.URL.Query())
+
+	var md5Sum string
+	switch getRequestAuthType(r) {
+	default:
+		// For all unknown auth types return error.
+		writeErrorResponse(w, r, ErrAccessDenied, r.URL.Path)
+		return
+	case authTypeAnonymous:
+		// http://docs.aws.amazon.com/AmazonS3/latest/dev/mpuAndPermissions.html
+		if s3Error := enforceBucketPolicy(bucket, "s3:PutObject", r.URL); s3Error != ErrNone {
+			writeErrorResponse(w, r, s3Error, r.URL.Path)
+			return
+		}
+	case authTypePresigned, authTypeSigned:
+		if s3Error := isReqAuthenticated(r); s3Error != ErrNone {
+			writeErrorResponse(w, r, s3Error, r.URL.Path)
+			return
+		}
+	}
+	completeMultipartBytes, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		errorIf(err, "Unable to complete multipart upload.")
+		writeErrorResponse(w, r, ErrInternalError, r.URL.Path)
+		return
+	}
+	complMultipartUpload := &completeMultipartUpload{}
+	if err = xml.Unmarshal(completeMultipartBytes, complMultipartUpload); err != nil {
+		errorIf(err, "Unable to parse complete multipart upload XML.")
+		writeErrorResponse(w, r, ErrMalformedXML, r.URL.Path)
+		return
+	}
+	if len(complMultipartUpload.Parts) == 0 {
+		writeErrorResponse(w, r, ErrMalformedXML, r.URL.Path)
+		return
+	}
+	if !sort.IsSorted(completedParts(complMultipartUpload.Parts)) {
+		writeErrorResponse(w, r, ErrInvalidPartOrder, r.URL.Path)
+		return
+	}
+	// Complete parts.
+	var completeParts []completePart
+	for _, part := range complMultipartUpload.Parts {
+		part.ETag = strings.TrimPrefix(part.ETag, "\"")
+		part.ETag = strings.TrimSuffix(part.ETag, "\"")
+		completeParts = append(completeParts, part)
+	}
+	// Complete multipart upload.
+	// Send 200 OK
+	setCommonHeaders(w)
+	w.WriteHeader(http.StatusOK)
+	// Xml headers need to be sent before we possibly send whitespace characters
+	// to the client.
+	_, err = w.Write([]byte(xml.Header))
+	if err != nil {
+		errorIf(err, "Unable to write XML header for complete multipart upload")
+		writeErrorResponseNoHeader(w, r, ErrInternalError, r.URL.Path)
+		return
+	}
+
+	doneCh := make(chan struct{})
+	// Signal that completeMultipartUpload is over via doneCh
+	go func(doneCh chan<- struct{}) {
+		md5Sum, err = api.ObjectAPI.CompleteMultipartUpload(bucket, object, uploadID, completeParts)
+		doneCh <- struct{}{}
+	}(doneCh)
+
+	sendWhiteSpaceChars(w, doneCh)
+	if err != nil {
+		errorIf(err, "Unable to complete multipart upload.")
+		switch oErr := err.(type) {
+		case PartTooSmall:
+			// Write part too small error.
+			writePartSmallErrorResponse(w, r, oErr)
+		default:
+			// Handle all other generic issues.
+			writeErrorResponseNoHeader(w, r, toAPIErrorCode(err), r.URL.Path)
+		}
+		return
+	}
+
+	// Get object location.
+	location := getLocation(r)
+	// Generate complete multipart response.
+	response := generateCompleteMultpartUploadResponse(bucket, object, location, md5Sum)
+	encodedSuccessResponse, err := xml.Marshal(response)
+	if err != nil {
+		errorIf(err, "Unable to parse CompleteMultipartUpload response")
+		writeErrorResponseNoHeader(w, r, ErrInternalError, r.URL.Path)
+		return
+	}
+
+	// Write success response.
+	w.Write(encodedSuccessResponse)
+	w.(http.Flusher).Flush()
+
+	// Fetch object info for notifications.
+	objInfo, err := api.ObjectAPI.GetObjectInfo(bucket, object)
+	if err != nil {
+		errorIf(err, "Unable to fetch object info for \"%s\"", path.Join(bucket, object))
+		return
+	}
+
+	if eventN.IsBucketNotificationSet(bucket) {
+		// Notify object created event.
+		eventNotify(eventData{
+			Type:    ObjectCreatedCompleteMultipartUpload,
+			Bucket:  bucket,
+			ObjInfo: objInfo,
+			ReqParams: map[string]string{
+				"sourceIPAddress": r.RemoteAddr,
+			},
+		})
+	}
+}
+
+/// Delete objectAPIHandlers
+
+// DeleteObjectHandler - delete an object
+func (api objectAPIHandlers) DeleteObjectHandler(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	bucket := vars["bucket"]
+	object := vars["object"]
+
+	switch getRequestAuthType(r) {
+	default:
+		// For all unknown auth types return error.
+		writeErrorResponse(w, r, ErrAccessDenied, r.URL.Path)
+		return
+	case authTypeAnonymous:
+		// http://docs.aws.amazon.com/AmazonS3/latest/dev/using-with-s3-actions.html
+		if s3Error := enforceBucketPolicy(bucket, "s3:DeleteObject", r.URL); s3Error != ErrNone {
+			writeErrorResponse(w, r, s3Error, r.URL.Path)
+			return
+		}
+	case authTypeSigned, authTypePresigned:
+		if s3Error := isReqAuthenticated(r); s3Error != ErrNone {
+			writeErrorResponse(w, r, s3Error, r.URL.Path)
+			return
+		}
+	}
+	/// http://docs.aws.amazon.com/AmazonS3/latest/API/RESTObjectDELETE.html
+	/// Ignore delete object errors, since we are suppposed to reply
+	/// only 204.
+	if err := api.ObjectAPI.DeleteObject(bucket, object); err != nil {
+		writeSuccessNoContent(w)
+		return
+	}
+	writeSuccessNoContent(w)
+
+	if eventN.IsBucketNotificationSet(bucket) {
+		// Notify object deleted event.
+		eventNotify(eventData{
+			Type:   ObjectRemovedDelete,
+			Bucket: bucket,
+			ObjInfo: ObjectInfo{
+				Name: object,
+			},
+			ReqParams: map[string]string{
+				"sourceIPAddress": r.RemoteAddr,
+			},
+		})
+	}
+}