API/CopyObject: If-None-Match should return Precondition failed. (#2164)

object-handlers-common.go

@@ -0,0 +1,223 @@
+/*
+ * Minio Cloud Storage, (C) 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 main
+
+import (
+	"net/http"
+	"strings"
+	"time"
+)
+
+// Validates the preconditions. Returns true if object content need not be written to http.ResponseWriter.
+func checkPreconditions(r *http.Request, w http.ResponseWriter, objInfo ObjectInfo) bool {
+	// Return false for methods other than GET and HEAD.
+	if r.Method != "GET" && r.Method != "HEAD" {
+		return false
+	}
+
+	// Headers to be set of object content is not going to be written to the client.
+	writeHeaders := func() {
+		// set common headers
+		setCommonHeaders(w)
+
+		// set object-related metadata headers
+		w.Header().Set("Last-Modified", objInfo.ModTime.UTC().Format(http.TimeFormat))
+
+		if objInfo.MD5Sum != "" {
+			w.Header().Set("ETag", "\""+objInfo.MD5Sum+"\"")
+		}
+	}
+	// If-Modified-Since : Return the object only if it has been modified since the specified time,
+	// otherwise return a 304 (not modified).
+	ifModifiedSinceHeader := r.Header.Get("If-Modified-Since")
+	if ifModifiedSinceHeader != "" {
+		if !ifModifiedSince(objInfo.ModTime, ifModifiedSinceHeader) {
+			// If the object is not modified since the specified time.
+			writeHeaders()
+			w.WriteHeader(http.StatusNotModified)
+			return true
+		}
+	}
+
+	// If-Unmodified-Since : Return the object only if it has not been modified since the specified
+	// time, otherwise return a 412 (precondition failed).
+	ifUnmodifiedSinceHeader := r.Header.Get("If-Unmodified-Since")
+	if ifUnmodifiedSinceHeader != "" {
+		if ifModifiedSince(objInfo.ModTime, ifUnmodifiedSinceHeader) {
+			// If the object is modified since the specified time.
+			writeHeaders()
+			writeErrorResponse(w, r, ErrPreconditionFailed, r.URL.Path)
+			return true
+		}
+	}
+
+	// If-Match : Return the object only if its entity tag (ETag) is the same as the one specified;
+	// otherwise return a 412 (precondition failed).
+	ifMatchETagHeader := r.Header.Get("If-Match")
+	if ifMatchETagHeader != "" {
+		if !isETagEqual(objInfo.MD5Sum, ifMatchETagHeader) {
+			// If the object ETag does not match with the specified ETag.
+			writeHeaders()
+			writeErrorResponse(w, r, ErrPreconditionFailed, r.URL.Path)
+			return true
+		}
+	}
+
+	// If-None-Match : Return the object only if its entity tag (ETag) is different from the
+	// one specified otherwise, return a 304 (not modified).
+	ifNoneMatchETagHeader := r.Header.Get("If-None-Match")
+	if ifNoneMatchETagHeader != "" {
+		if isETagEqual(objInfo.MD5Sum, ifNoneMatchETagHeader) {
+			// If the object ETag matches with the specified ETag.
+			writeHeaders()
+			w.WriteHeader(http.StatusNotModified)
+			return true
+		}
+	}
+	// Object content should be written to http.ResponseWriter
+	return false
+}
+
+// returns true if object was modified after givenTime.
+func ifModifiedSince(objTime time.Time, givenTimeStr string) bool {
+	if objTime.IsZero() || objTime.Equal(time.Unix(0, 0)) {
+		// If the object doesn't have a modtime (IsZero), or the modtime
+		// is obviously garbage (Unix time == 0), then ignore modtimes
+		// and don't process the If-Modified-Since header.
+		return false
+	}
+	givenTime, err := time.Parse(http.TimeFormat, givenTimeStr)
+	if err != nil {
+		return true
+	}
+	// The Date-Modified header truncates sub-second precision, so
+	// use mtime < t+1s instead of mtime <= t to check for unmodified.
+	if objTime.After(givenTime.Add(1 * time.Second)) {
+		return true
+	}
+	return false
+}
+
+// canonicalizeETag returns ETag with leading and trailing double-quotes removed,
+// if any present
+func canonicalizeETag(etag string) string {
+	canonicalETag := strings.TrimPrefix(etag, "\"")
+	return strings.TrimSuffix(canonicalETag, "\"")
+}
+
+// isETagEqual return true if the canonical representations of two ETag strings
+// are equal, false otherwise
+func isETagEqual(left, right string) bool {
+	return canonicalizeETag(left) == canonicalizeETag(right)
+}
+
+// checkCopySource implements x-amz-copy-source-if-modified-since and
+// x-amz-copy-source-if-unmodified-since checks.
+//
+// modtime is the modification time of the resource to be served, or
+// IsZero(). return value is whether this request is now complete.
+func checkCopySourceLastModified(w http.ResponseWriter, r *http.Request, modtime time.Time) bool {
+	// writer always has quoted string
+	// transform reader's etag to
+	if r.Method != "PUT" {
+		return false
+	}
+	if modtime.IsZero() || modtime.Equal(time.Unix(0, 0)) {
+		// If the object doesn't have a modtime (IsZero), or the modtime
+		// is obviously garbage (Unix time == 0), then ignore modtimes
+		// and don't process the If-Modified-Since header.
+		return false
+	}
+	// The Date-Modified header truncates sub-second precision, so
+	// use mtime < t+1s instead of mtime <= t to check for unmodified.
+	if _, ok := r.Header["x-amz-copy-source-if-modified-since"]; ok {
+		// Return the object only if it has been modified since the
+		// specified time, otherwise return a 304 error (not modified).
+		t, err := time.Parse(http.TimeFormat, r.Header.Get("x-amz-copy-source-if-modified-since"))
+		if err == nil && modtime.Before(t.Add(1*time.Second)) {
+			h := w.Header()
+			// Remove Content headers if set
+			delete(h, "Content-Type")
+			delete(h, "Content-Length")
+			delete(h, "Content-Range")
+			w.WriteHeader(http.StatusNotModified)
+			return true
+		}
+	} else if _, ok := r.Header["x-amz-copy-source-if-unmodified-since"]; ok {
+		// Return the object only if it has not been modified since the
+		// specified time, otherwise return a 412 error (precondition failed).
+		t, err := time.Parse(http.TimeFormat, r.Header.Get("x-amz-copy-source-if-unmodified-since"))
+		if err == nil && modtime.After(t.Add(1*time.Second)) {
+			h := w.Header()
+			// Remove Content headers if set
+			delete(h, "Content-Type")
+			delete(h, "Content-Length")
+			delete(h, "Content-Range")
+			writeErrorResponse(w, r, ErrPreconditionFailed, r.URL.Path)
+			return true
+		}
+	}
+	w.Header().Set("Last-Modified", modtime.UTC().Format(http.TimeFormat))
+	return false
+}
+
+// checkCopySourceETag implements x-amz-copy-source-if-match and
+// x-amz-copy-source-if-none-match checks.
+//
+// The ETag must have been previously set in the ResponseWriter's
+// headers. The return value is whether this request is now considered
+// complete.
+func checkCopySourceETag(w http.ResponseWriter, r *http.Request) bool {
+	// writer always has quoted string
+	// transform reader's etag to
+	if r.Method != "PUT" {
+		return false
+	}
+	etag := w.Header().Get("ETag")
+	// Tag must be provided...
+	if etag == "" {
+		return false
+	}
+	if inm := r.Header.Get("x-amz-copy-source-if-none-match"); inm != "" {
+		// Return the object only if its entity tag (ETag) is
+		// different from the one specified; otherwise, the
+		// request returns a 412 HTTP status code error (failed precondition).
+		if isETagEqual(inm, etag) || isETagEqual(inm, "*") {
+			h := w.Header()
+			// Remove Content headers if set
+			delete(h, "Content-Type")
+			delete(h, "Content-Length")
+			delete(h, "Content-Range")
+			writeErrorResponse(w, r, ErrPreconditionFailed, r.URL.Path)
+			return true
+		}
+	} else if inm := r.Header.Get("x-amz-copy-source-if-match"); !isETagEqual(inm, "") {
+		// Return the object only if its entity tag (ETag) is the same
+		// as the one specified; otherwise, return a 412 (precondition failed).
+		if !isETagEqual(inm, etag) {
+			h := w.Header()
+			// Remove Content headers if set
+			delete(h, "Content-Type")
+			delete(h, "Content-Length")
+			delete(h, "Content-Range")
+			writeErrorResponse(w, r, ErrPreconditionFailed, r.URL.Path)
+			return true
+		}
+	}
+	return false
+
+}

object-handlers.go

@@ -163,7 +163,7 @@ func (api objectAPIHandlers) GetObjectHandler(w http.ResponseWriter, r *http.Req
 		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
-			// occured then no point in setting StatusCode and
+			// occurred then no point in setting StatusCode and
 			// sending error XML.
 			apiErr := toAPIErrorCode(err)
 			writeErrorResponse(w, r, apiErr, r.URL.Path)
@@ -178,96 +178,6 @@ func (api objectAPIHandlers) GetObjectHandler(w http.ResponseWriter, r *http.Req
 	}
 }
 
-// Validates the preconditions. Returns true if object content need not be written to http.ResponseWriter.
-func checkPreconditions(r *http.Request, w http.ResponseWriter, objInfo ObjectInfo) bool {
-	// Headers to be set of object content is not going to be written to the client.
-	writeHeaders := func() {
-		// set common headers
-		setCommonHeaders(w)
-
-		// set object-related metadata headers
-		w.Header().Set("Last-Modified", objInfo.ModTime.UTC().Format(http.TimeFormat))
-
-		if objInfo.MD5Sum != "" {
-			w.Header().Set("ETag", "\""+objInfo.MD5Sum+"\"")
-		}
-	}
-	// If-Modified-Since : Return the object only if it has been modified since the specified time,
-	// otherwise return a 304 (not modified).
-	ifModifiedSinceHeader := r.Header.Get("If-Modified-Since")
-	if ifModifiedSinceHeader != "" {
-		if !ifModifiedSince(objInfo.ModTime, ifModifiedSinceHeader) {
-			// If the object is not modified since the specified time.
-			writeHeaders()
-			w.WriteHeader(http.StatusNotModified)
-			return true
-		}
-	}
-
-	// If-Unmodified-Since : Return the object only if it has not been modified since the specified
-	// time, otherwise return a 412 (precondition failed).
-	ifUnmodifiedSinceHeader := r.Header.Get("If-Unmodified-Since")
-	if ifUnmodifiedSinceHeader != "" {
-		if ifModifiedSince(objInfo.ModTime, ifUnmodifiedSinceHeader) {
-			// If the object is modified since the specified time.
-			writeHeaders()
-			writeErrorResponse(w, r, ErrPreconditionFailed, r.URL.Path)
-			return true
-		}
-	}
-
-	// If-Match : Return the object only if its entity tag (ETag) is the same as the one specified;
-	// otherwise return a 412 (precondition failed).
-	ifMatchETagHeader := r.Header.Get("If-Match")
-	if ifMatchETagHeader != "" {
-		if !isETagEqual(objInfo.MD5Sum, ifMatchETagHeader) {
-			// If the object ETag does not match with the specified ETag.
-			writeHeaders()
-			writeErrorResponse(w, r, ErrPreconditionFailed, r.URL.Path)
-			return true
-		}
-	}
-
-	// If-None-Match : Return the object only if its entity tag (ETag) is different from the
-	// one specified otherwise, return a 304 (not modified).
-	ifNoneMatchETagHeader := r.Header.Get("If-None-Match")
-	if ifNoneMatchETagHeader != "" {
-		if isETagEqual(objInfo.MD5Sum, ifNoneMatchETagHeader) {
-			// If the object ETag matches with the specified ETag.
-			writeHeaders()
-			w.WriteHeader(http.StatusNotModified)
-			return true
-		}
-	}
-	// Object content should be written to http.ResponseWriter
-	return false
-}
-
-// returns true if object was modified after givenTime.
-func ifModifiedSince(objTime time.Time, givenTimeStr string) bool {
-	givenTime, err := time.Parse(http.TimeFormat, givenTimeStr)
-	if err != nil {
-		return true
-	}
-	if objTime.After(givenTime) {
-		return true
-	}
-	return false
-}
-
-// canonicalizeETag returns ETag with leading and trailing double-quotes removed,
-// if any present
-func canonicalizeETag(etag string) string {
-	canonicalETag := strings.TrimPrefix(etag, "\"")
-	return strings.TrimSuffix(canonicalETag, "\"")
-}
-
-// isETagEqual return true if the canonical representations of two ETag strings
-// are equal, false otherwise
-func isETagEqual(left, right string) bool {
-	return canonicalizeETag(left) == canonicalizeETag(right)
-}
-
 // HeadObjectHandler - HEAD Object
 // -----------
 // The HEAD operation retrieves metadata from an object without returning the object itself.
@@ -458,103 +368,6 @@ func (api objectAPIHandlers) CopyObjectHandler(w http.ResponseWriter, r *http.Re
 	pipeReader.Close()
 }
 
-// checkCopySource implements x-amz-copy-source-if-modified-since and
-// x-amz-copy-source-if-unmodified-since checks.
-//
-// modtime is the modification time of the resource to be served, or
-// IsZero(). return value is whether this request is now complete.
-func checkCopySourceLastModified(w http.ResponseWriter, r *http.Request, modtime time.Time) bool {
-	// writer always has quoted string
-	// transform reader's etag to
-	if r.Method != "PUT" {
-		return false
-	}
-	if modtime.IsZero() || modtime.Equal(time.Unix(0, 0)) {
-		// If the object doesn't have a modtime (IsZero), or the modtime
-		// is obviously garbage (Unix time == 0), then ignore modtimes
-		// and don't process the If-Modified-Since header.
-		return false
-	}
-	// The Date-Modified header truncates sub-second precision, so
-	// use mtime < t+1s instead of mtime <= t to check for unmodified.
-	if _, ok := r.Header["x-amz-copy-source-if-modified-since"]; ok {
-		// Return the object only if it has been modified since the
-		// specified time, otherwise return a 304 error (not modified).
-		t, err := time.Parse(http.TimeFormat, r.Header.Get("x-amz-copy-source-if-modified-since"))
-		if err == nil && modtime.Before(t.Add(1*time.Second)) {
-			h := w.Header()
-			// Remove Content headers if set
-			delete(h, "Content-Type")
-			delete(h, "Content-Length")
-			delete(h, "Content-Range")
-			w.WriteHeader(http.StatusNotModified)
-			return true
-		}
-	} else if _, ok := r.Header["x-amz-copy-source-if-unmodified-since"]; ok {
-		// Return the object only if it has not been modified since the
-		// specified time, otherwise return a 412 error (precondition failed).
-		t, err := time.Parse(http.TimeFormat, r.Header.Get("x-amz-copy-source-if-unmodified-since"))
-		if err == nil && modtime.After(t.Add(1*time.Second)) {
-			h := w.Header()
-			// Remove Content headers if set
-			delete(h, "Content-Type")
-			delete(h, "Content-Length")
-			delete(h, "Content-Range")
-			writeErrorResponse(w, r, ErrPreconditionFailed, r.URL.Path)
-			return true
-		}
-	}
-	w.Header().Set("Last-Modified", modtime.UTC().Format(http.TimeFormat))
-	return false
-}
-
-// checkCopySourceETag implements x-amz-copy-source-if-match and
-// x-amz-copy-source-if-none-match checks.
-//
-// The ETag must have been previously set in the ResponseWriter's
-// headers. The return value is whether this request is now considered
-// complete.
-func checkCopySourceETag(w http.ResponseWriter, r *http.Request) bool {
-	// writer always has quoted string
-	// transform reader's etag to
-	if r.Method != "PUT" {
-		return false
-	}
-	etag := w.Header().Get("ETag")
-	// Tag must be provided...
-	if etag == "" {
-		return false
-	}
-	if inm := r.Header.Get("x-amz-copy-source-if-none-match"); inm != "" {
-		// Return the object only if its entity tag (ETag) is
-		// different from the one specified; otherwise, return a 304
-		// (not modified).
-		if isETagEqual(inm, etag) || isETagEqual(inm, "*") {
-			h := w.Header()
-			// Remove Content headers if set
-			delete(h, "Content-Type")
-			delete(h, "Content-Length")
-			delete(h, "Content-Range")
-			w.WriteHeader(http.StatusNotModified)
-			return true
-		}
-	} else if inm := r.Header.Get("x-amz-copy-source-if-match"); !isETagEqual(inm, "") {
-		// Return the object only if its entity tag (ETag) is the same
-		// as the one specified; otherwise, return a 412 (precondition failed).
-		if !isETagEqual(inm, etag) {
-			h := w.Header()
-			// Remove Content headers if set
-			delete(h, "Content-Type")
-			delete(h, "Content-Length")
-			delete(h, "Content-Range")
-			writeErrorResponse(w, r, ErrPreconditionFailed, r.URL.Path)
-			return true
-		}
-	}
-	return false
-
-}
-
 // PutObjectHandler - PUT Object
 // ----------
 // This implementation of the PUT operation adds an object to a bucket.