mirror of
https://github.com/ceph/ceph-csi.git
synced 2025-03-09 17:09:29 +00:00
f87d06ed85
Several packages are only used while running the e2e suite. These packages are less important to update, as the they can not influence the final executable that is part of the Ceph-CSI container-image. By moving these dependencies out of the main Ceph-CSI go.mod, it is easier to identify if a reported CVE affects Ceph-CSI, or only the testing (like most of the Kubernetes CVEs). Signed-off-by: Niels de Vos <ndevos@ibm.com>
99 lines
2.9 KiB
Go
99 lines
2.9 KiB
Go
/*
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Copyright 2017 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package io
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import (
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"bytes"
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"errors"
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"fmt"
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"io"
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"io/ioutil"
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)
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// ErrLimitReached means that the read limit is reached.
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var ErrLimitReached = errors.New("the read limit is reached")
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// ConsistentRead repeatedly reads a file until it gets the same content twice.
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// This is useful when reading files in /proc that are larger than page size
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// and kernel may modify them between individual read() syscalls.
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// It returns InconsistentReadError when it cannot get a consistent read in
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// given nr. of attempts. Caller should retry, kernel is probably under heavy
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// mount/unmount load.
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func ConsistentRead(filename string, attempts int) ([]byte, error) {
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return consistentReadSync(filename, attempts, nil)
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}
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// consistentReadSync is the main functionality of ConsistentRead but
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// introduces a sync callback that can be used by the tests to mutate the file
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// from which the test data is being read
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func consistentReadSync(filename string, attempts int, sync func(int)) ([]byte, error) {
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oldContent, err := ioutil.ReadFile(filename)
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if err != nil {
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return nil, err
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}
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for i := 0; i < attempts; i++ {
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if sync != nil {
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sync(i)
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}
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newContent, err := ioutil.ReadFile(filename)
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if err != nil {
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return nil, err
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}
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if bytes.Compare(oldContent, newContent) == 0 {
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return newContent, nil
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}
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// Files are different, continue reading
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oldContent = newContent
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}
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return nil, InconsistentReadError{filename, attempts}
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}
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// InconsistentReadError is returned from ConsistentRead when it cannot get
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// a consistent read in given nr. of attempts. Caller should retry, kernel is
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// probably under heavy mount/unmount load.
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type InconsistentReadError struct {
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filename string
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attempts int
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}
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func (i InconsistentReadError) Error() string {
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return fmt.Sprintf("could not get consistent content of %s after %d attempts", i.filename, i.attempts)
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}
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var _ error = InconsistentReadError{}
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func IsInconsistentReadError(err error) bool {
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if _, ok := err.(InconsistentReadError); ok {
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return true
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}
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return false
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}
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// ReadAtMost reads up to `limit` bytes from `r`, and reports an error
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// when `limit` bytes are read.
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func ReadAtMost(r io.Reader, limit int64) ([]byte, error) {
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limitedReader := &io.LimitedReader{R: r, N: limit}
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data, err := ioutil.ReadAll(limitedReader)
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if err != nil {
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return data, err
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}
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if limitedReader.N <= 0 {
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return data, ErrLimitReached
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}
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return data, nil
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}
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