minio/cmd/object-handlers-common.go
2020-10-02 13:36:13 -07:00

319 lines
12 KiB
Go

/*
* MinIO Cloud Storage, (C) 2016, 2017, 2018 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 (
"context"
"fmt"
"net/http"
"regexp"
"strconv"
"time"
xhttp "github.com/minio/minio/cmd/http"
"github.com/minio/minio/pkg/bucket/lifecycle"
"github.com/minio/minio/pkg/event"
"github.com/minio/minio/pkg/handlers"
)
var (
etagRegex = regexp.MustCompile("\"*?([^\"]*?)\"*?$")
)
// Validates the preconditions for CopyObjectPart, returns true if CopyObjectPart
// operation should not proceed. Preconditions supported are:
// x-amz-copy-source-if-modified-since
// x-amz-copy-source-if-unmodified-since
// x-amz-copy-source-if-match
// x-amz-copy-source-if-none-match
func checkCopyObjectPartPreconditions(ctx context.Context, w http.ResponseWriter, r *http.Request, objInfo ObjectInfo) bool {
return checkCopyObjectPreconditions(ctx, w, r, objInfo)
}
// Validates the preconditions for CopyObject, returns true if CopyObject operation should not proceed.
// Preconditions supported are:
// x-amz-copy-source-if-modified-since
// x-amz-copy-source-if-unmodified-since
// x-amz-copy-source-if-match
// x-amz-copy-source-if-none-match
func checkCopyObjectPreconditions(ctx context.Context, w http.ResponseWriter, r *http.Request, objInfo ObjectInfo) bool {
// Return false for methods other than GET and HEAD.
if r.Method != http.MethodPut {
return false
}
// 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.
if objInfo.ModTime.IsZero() || objInfo.ModTime.Equal(time.Unix(0, 0)) {
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(xhttp.LastModified, objInfo.ModTime.UTC().Format(http.TimeFormat))
if objInfo.ETag != "" {
w.Header()[xhttp.ETag] = []string{"\"" + objInfo.ETag + "\""}
}
}
// x-amz-copy-source-if-modified-since: Return the object only if it has been modified
// since the specified time otherwise return 412 (precondition failed).
ifModifiedSinceHeader := r.Header.Get(xhttp.AmzCopySourceIfModifiedSince)
if ifModifiedSinceHeader != "" {
if givenTime, err := time.Parse(http.TimeFormat, ifModifiedSinceHeader); err == nil {
if !ifModifiedSince(objInfo.ModTime, givenTime) {
// If the object is not modified since the specified time.
writeHeaders()
writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrPreconditionFailed), r.URL, guessIsBrowserReq(r))
return true
}
}
}
// x-amz-copy-source-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(xhttp.AmzCopySourceIfUnmodifiedSince)
if ifUnmodifiedSinceHeader != "" {
if givenTime, err := time.Parse(http.TimeFormat, ifUnmodifiedSinceHeader); err == nil {
if ifModifiedSince(objInfo.ModTime, givenTime) {
// If the object is modified since the specified time.
writeHeaders()
writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrPreconditionFailed), r.URL, guessIsBrowserReq(r))
return true
}
}
}
// x-amz-copy-source-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(xhttp.AmzCopySourceIfMatch)
if ifMatchETagHeader != "" {
if !isETagEqual(objInfo.ETag, ifMatchETagHeader) {
// If the object ETag does not match with the specified ETag.
writeHeaders()
writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrPreconditionFailed), r.URL, guessIsBrowserReq(r))
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(xhttp.AmzCopySourceIfNoneMatch)
if ifNoneMatchETagHeader != "" {
if isETagEqual(objInfo.ETag, ifNoneMatchETagHeader) {
// If the object ETag matches with the specified ETag.
writeHeaders()
writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrPreconditionFailed), r.URL, guessIsBrowserReq(r))
return true
}
}
// Object content should be written to http.ResponseWriter
return false
}
// Validates the preconditions. Returns true if GET/HEAD operation should not proceed.
// Preconditions supported are:
// If-Modified-Since
// If-Unmodified-Since
// If-Match
// If-None-Match
func checkPreconditions(ctx context.Context, w http.ResponseWriter, r *http.Request, objInfo ObjectInfo, opts ObjectOptions) bool {
// Return false for methods other than GET and HEAD.
if r.Method != http.MethodGet && r.Method != http.MethodHead {
return false
}
// 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.
if objInfo.ModTime.IsZero() || objInfo.ModTime.Equal(time.Unix(0, 0)) {
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(xhttp.LastModified, objInfo.ModTime.UTC().Format(http.TimeFormat))
if objInfo.ETag != "" {
w.Header()[xhttp.ETag] = []string{"\"" + objInfo.ETag + "\""}
}
}
// Check if the part number is correct.
if opts.PartNumber > 1 && opts.PartNumber > len(objInfo.Parts) {
writeHeaders()
w.WriteHeader(http.StatusRequestedRangeNotSatisfiable)
return true
}
// 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(xhttp.IfModifiedSince)
if ifModifiedSinceHeader != "" {
if givenTime, err := time.Parse(http.TimeFormat, ifModifiedSinceHeader); err == nil {
if !ifModifiedSince(objInfo.ModTime, givenTime) {
// 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(xhttp.IfUnmodifiedSince)
if ifUnmodifiedSinceHeader != "" {
if givenTime, err := time.Parse(http.TimeFormat, ifUnmodifiedSinceHeader); err == nil {
if ifModifiedSince(objInfo.ModTime, givenTime) {
// If the object is modified since the specified time.
writeHeaders()
writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrPreconditionFailed), r.URL, guessIsBrowserReq(r))
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(xhttp.IfMatch)
if ifMatchETagHeader != "" {
if !isETagEqual(objInfo.ETag, ifMatchETagHeader) {
// If the object ETag does not match with the specified ETag.
writeHeaders()
writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrPreconditionFailed), r.URL, guessIsBrowserReq(r))
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(xhttp.IfNoneMatch)
if ifNoneMatchETagHeader != "" {
if isETagEqual(objInfo.ETag, 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, givenTime time.Time) bool {
// The Date-Modified header truncates sub-second precision, so
// use mtime < t+1s instead of mtime <= t to check for unmodified.
return objTime.After(givenTime.Add(1 * time.Second))
}
// canonicalizeETag returns ETag with leading and trailing double-quotes removed,
// if any present
func canonicalizeETag(etag string) string {
return etagRegex.ReplaceAllString(etag, "$1")
}
// 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)
}
// setPutObjHeaders sets all the necessary headers returned back
// upon a success Put/Copy/CompleteMultipart/Delete requests
// to activate delete only headers set delete as true
func setPutObjHeaders(w http.ResponseWriter, objInfo ObjectInfo, delete bool) {
// We must not use the http.Header().Set method here because some (broken)
// clients expect the ETag header key to be literally "ETag" - not "Etag" (case-sensitive).
// Therefore, we have to set the ETag directly as map entry.
if objInfo.ETag != "" && !delete {
w.Header()[xhttp.ETag] = []string{`"` + objInfo.ETag + `"`}
}
// Set the relevant version ID as part of the response header.
if objInfo.VersionID != "" {
w.Header()[xhttp.AmzVersionID] = []string{objInfo.VersionID}
// If version is a deleted marker, set this header as well
if objInfo.DeleteMarker && delete { // only returned during delete object
w.Header()[xhttp.AmzDeleteMarker] = []string{strconv.FormatBool(objInfo.DeleteMarker)}
}
}
if lc, err := globalLifecycleSys.Get(objInfo.Bucket); err == nil && !delete {
ruleID, expiryTime := lc.PredictExpiryTime(lifecycle.ObjectOpts{
Name: objInfo.Name,
UserTags: objInfo.UserTags,
VersionID: objInfo.VersionID,
ModTime: objInfo.ModTime,
IsLatest: objInfo.IsLatest,
DeleteMarker: objInfo.DeleteMarker,
})
if !expiryTime.IsZero() {
w.Header()[xhttp.AmzExpiration] = []string{
fmt.Sprintf(`expiry-date="%s", rule-id="%s"`, expiryTime.Format(http.TimeFormat), ruleID),
}
}
}
}
// deleteObject is a convenient wrapper to delete an object, this
// is a common function to be called from object handlers and
// web handlers.
func deleteObject(ctx context.Context, obj ObjectLayer, cache CacheObjectLayer, bucket, object string, w http.ResponseWriter, r *http.Request, opts ObjectOptions) (objInfo ObjectInfo, err error) {
deleteObject := obj.DeleteObject
if cache != nil {
deleteObject = cache.DeleteObject
}
// Proceed to delete the object.
objInfo, err = deleteObject(ctx, bucket, object, opts)
if objInfo.Name != "" {
// Requesting only a delete marker which was successfully attempted.
if objInfo.DeleteMarker {
// Notify object deleted marker event.
sendEvent(eventArgs{
EventName: event.ObjectRemovedDeleteMarkerCreated,
BucketName: bucket,
Object: objInfo,
ReqParams: extractReqParams(r),
RespElements: extractRespElements(w),
UserAgent: r.UserAgent(),
Host: handlers.GetSourceIP(r),
})
} else {
// Notify object deleted event.
sendEvent(eventArgs{
EventName: event.ObjectRemovedDelete,
BucketName: bucket,
Object: objInfo,
ReqParams: extractReqParams(r),
RespElements: extractRespElements(w),
UserAgent: r.UserAgent(),
Host: handlers.GetSourceIP(r),
})
}
}
return objInfo, err
}