mirror of
https://github.com/alist-org/gofakes3.git
synced 2025-12-24 12:58:04 +08:00
d11e83aaf8
Why: Incorrect range handling cases causes s3manager downloads to fail. * When end extends beyond available data it should return data from "start" to the end of the available data. Currently it returns invalid range error. From RFC-7233: > If the last-byte-pos value is.. greater than or equal to the current > length of the representation data, the byte range is interpreted as > the remainder of the representation (i.e., the server replaces the > value of last-byte-pos with a value that is one less than the current > length of the selected representation). * A "-0" suffix byte range is "not satisfiable" according to RFC and should return an invalid range error. Currently it just returns an empty data set. Also from RFC-7233: > If a valid byte-range-set includes ... or at least one > suffix-byte-range-spec with a non-zero suffix-length, then the > byte-range-set is satisfiable. Otherwise, the byte-range-set is > unsatisfiable.
127 lines
2.5 KiB
Go
127 lines
2.5 KiB
Go
package gofakes3
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import (
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"fmt"
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"net/http"
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"strconv"
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"strings"
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)
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type ObjectRange struct {
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Start, Length int64
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}
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func (o *ObjectRange) writeHeader(sz int64, w http.ResponseWriter) {
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if o != nil {
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w.Header().Set("Content-Range", fmt.Sprintf("bytes %d-%d/%d", o.Start, o.Start+o.Length-1, sz))
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w.Header().Set("Content-Length", fmt.Sprintf("%d", o.Length))
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} else {
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w.Header().Set("Content-Length", fmt.Sprintf("%d", sz))
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}
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}
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type ObjectRangeRequest struct {
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Start, End int64
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FromEnd bool
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}
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const RangeNoEnd = -1
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func (o *ObjectRangeRequest) Range(size int64) (*ObjectRange, error) {
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if o == nil {
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return nil, nil
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}
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var start, length int64
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if !o.FromEnd {
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start = o.Start
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end := o.End
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if o.End == RangeNoEnd {
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// If no end is specified, range extends to end of the file.
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length = size - start
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} else {
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length = end - start + 1
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}
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} else {
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// If no start is specified, end specifies the range start relative
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// to the end of the file.
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end := o.End
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start = size - end
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length = size - start
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}
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if start < 0 || length < 0 || start >= size {
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return nil, ErrInvalidRange
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}
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if start+length > size {
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return &ObjectRange{Start: start, Length: size - start}, nil
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}
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return &ObjectRange{Start: start, Length: length}, nil
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}
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// parseRangeHeader parses a single byte range from the Range header.
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//
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// Amazon S3 doesn't support retrieving multiple ranges of data per GET request:
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// https://docs.aws.amazon.com/AmazonS3/latest/API/RESTObjectGET.html
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func parseRangeHeader(s string) (*ObjectRangeRequest, error) {
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if s == "" {
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return nil, nil
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}
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const b = "bytes="
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if !strings.HasPrefix(s, b) {
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return nil, ErrInvalidRange
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}
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ranges := strings.Split(s[len(b):], ",")
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if len(ranges) > 1 {
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return nil, ErrorMessage(ErrNotImplemented, "multiple ranges not supported")
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}
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rnge := strings.TrimSpace(ranges[0])
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if len(rnge) == 0 {
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return nil, ErrInvalidRange
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}
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i := strings.Index(rnge, "-")
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if i < 0 {
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return nil, ErrInvalidRange
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}
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var o ObjectRangeRequest
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start, end := strings.TrimSpace(rnge[:i]), strings.TrimSpace(rnge[i+1:])
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if start == "" {
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o.FromEnd = true
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i, err := strconv.ParseInt(end, 10, 64)
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if err != nil {
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return nil, ErrInvalidRange
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}
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o.End = i
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} else {
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i, err := strconv.ParseInt(start, 10, 64)
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if err != nil || i < 0 {
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return nil, ErrInvalidRange
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}
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o.Start = i
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if end != "" {
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i, err := strconv.ParseInt(end, 10, 64)
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if err != nil || o.Start > i {
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return nil, ErrInvalidRange
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}
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o.End = i
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} else {
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o.End = RangeNoEnd
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}
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}
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return &o, nil
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}
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