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/handler-utils.go

@@ -0,0 +1,145 @@
+/*
+ * Minio Cloud Storage, (C) 2015, 2016 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 (
+	"io"
+	"io/ioutil"
+	"mime/multipart"
+	"net/http"
+	"strings"
+	"time"
+)
+
+// Validates location constraint in PutBucket request body.
+// The location value in the request body should match the
+// region configured at serverConfig, otherwise error is returned.
+func isValidLocationConstraint(r *http.Request) (s3Error APIErrorCode) {
+	serverRegion := serverConfig.GetRegion()
+	// If the request has no body with content-length set to 0,
+	// we do not have to validate location constraint. Bucket will
+	// be created at default region.
+	if r.ContentLength == 0 {
+		return ErrNone
+	}
+	locationConstraint := createBucketLocationConfiguration{}
+	if err := xmlDecoder(r.Body, &locationConstraint, r.ContentLength); err != nil {
+		if err == io.EOF && r.ContentLength == -1 {
+			// EOF is a valid condition here when ContentLength is -1.
+			return ErrNone
+		}
+		errorIf(err, "Unable to xml decode location constraint")
+		// Treat all other failures as XML parsing errors.
+		return ErrMalformedXML
+	} // Successfully decoded, proceed to verify the region.
+
+	// Once region has been obtained we proceed to verify it.
+	incomingRegion := locationConstraint.Location
+	if incomingRegion == "" {
+		// Location constraint is empty for region "us-east-1",
+		// in accordance with protocol.
+		incomingRegion = "us-east-1"
+	}
+	// Return errInvalidRegion if location constraint does not match
+	// with configured region.
+	s3Error = ErrNone
+	if serverRegion != incomingRegion {
+		s3Error = ErrInvalidRegion
+	}
+	return s3Error
+}
+
+// Supported headers that needs to be extracted.
+var supportedHeaders = []string{
+	"content-type",
+	"cache-control",
+	"content-encoding",
+	"content-disposition",
+	// Add more supported headers here.
+}
+
+// extractMetadataFromHeader extracts metadata from HTTP header.
+func extractMetadataFromHeader(header http.Header) map[string]string {
+	metadata := make(map[string]string)
+	// Save standard supported headers.
+	for _, supportedHeader := range supportedHeaders {
+		canonicalHeader := http.CanonicalHeaderKey(supportedHeader)
+		// HTTP headers are case insensitive, look for both canonical
+		// and non canonical entries.
+		if _, ok := header[canonicalHeader]; ok {
+			metadata[supportedHeader] = header.Get(canonicalHeader)
+		} else if _, ok := header[supportedHeader]; ok {
+			metadata[supportedHeader] = header.Get(supportedHeader)
+		}
+	}
+	// Go through all other headers for any additional headers that needs to be saved.
+	for key := range header {
+		cKey := http.CanonicalHeaderKey(key)
+		if strings.HasPrefix(cKey, "X-Amz-Meta-") {
+			metadata[cKey] = header.Get(cKey)
+		} else if strings.HasPrefix(key, "X-Minio-Meta-") {
+			metadata[cKey] = header.Get(cKey)
+		}
+	}
+	// Return.
+	return metadata
+}
+
+// Extract form fields and file data from a HTTP POST Policy
+func extractPostPolicyFormValues(reader *multipart.Reader) (filePart io.Reader, fileName string, formValues map[string]string, err error) {
+	/// HTML Form values
+	formValues = make(map[string]string)
+	fileName = ""
+	for err == nil {
+		var part *multipart.Part
+		part, err = reader.NextPart()
+		if part != nil {
+			canonicalFormName := http.CanonicalHeaderKey(part.FormName())
+			if canonicalFormName != "File" {
+				var buffer []byte
+				limitReader := io.LimitReader(part, maxFormFieldSize+1)
+				buffer, err = ioutil.ReadAll(limitReader)
+				if err != nil {
+					return nil, "", nil, err
+				}
+				if int64(len(buffer)) > maxFormFieldSize {
+					return nil, "", nil, errSizeUnexpected
+				}
+				formValues[canonicalFormName] = string(buffer)
+			} else {
+				filePart = io.LimitReader(part, maxObjectSize)
+				fileName = part.FileName()
+				// As described in S3 spec, we expect file to be the last form field
+				break
+			}
+		}
+	}
+	return filePart, fileName, formValues, nil
+}
+
+// Send whitespace character, once every 5secs, until CompleteMultipartUpload is done.
+// CompleteMultipartUpload method of the object layer indicates that it's done via doneCh
+func sendWhiteSpaceChars(w http.ResponseWriter, doneCh <-chan struct{}) {
+	for {
+		select {
+		case <-time.After(5 * time.Second):
+			w.Write([]byte(" "))
+		case <-doneCh:
+			return
+		}
+	}
+}