prometheus/storage/local/chunk/delta_test.go
beorn7 485ac8dff7 storage: Verify validity of byte length when unmarshalling (double)delta chunks
This makes sure a division-by-zero crash cannot happen in the Len()
method.

Fixes #2773
2016-12-13 17:07:27 +01:00

117 lines
3.4 KiB
Go

// Copyright 2016 The Prometheus Authors
// 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.
// Note: this file has tests for code in both delta.go and doubledelta.go --
// it may make sense to split those out later, but given that the tests are
// near-identical and share a helper, this feels simpler for now.
package chunk
import (
"bytes"
"encoding/binary"
"strings"
"testing"
"github.com/prometheus/common/model"
)
func TestUnmarshalingCorruptedDeltaReturnsAnError(t *testing.T) {
var verifyUnmarshallingError = func(
err error,
chunkTypeName string,
unmarshalMethod string,
expectedStr string,
) {
if err == nil {
t.Errorf("Failed to obtain an error when unmarshalling corrupt %s (from %s)", chunkTypeName, unmarshalMethod)
return
}
if !strings.Contains(err.Error(), expectedStr) {
t.Errorf(
"'%s' not present in error when unmarshalling corrupt %s (from %s): '%s'",
expectedStr,
chunkTypeName,
unmarshalMethod,
err.Error())
}
}
cases := []struct {
chunkTypeName string
chunkConstructor func(deltaBytes, deltaBytes, bool, int) Chunk
minHeaderLen int
chunkLenPos int
timeBytesPos int
}{
{
chunkTypeName: "deltaEncodedChunk",
chunkConstructor: func(a, b deltaBytes, c bool, d int) Chunk {
return newDeltaEncodedChunk(a, b, c, d)
},
minHeaderLen: deltaHeaderBytes,
chunkLenPos: deltaHeaderBufLenOffset,
timeBytesPos: deltaHeaderTimeBytesOffset,
},
{
chunkTypeName: "doubleDeltaEncodedChunk",
chunkConstructor: func(a, b deltaBytes, c bool, d int) Chunk {
return newDoubleDeltaEncodedChunk(a, b, c, d)
},
minHeaderLen: doubleDeltaHeaderMinBytes,
chunkLenPos: doubleDeltaHeaderBufLenOffset,
timeBytesPos: doubleDeltaHeaderTimeBytesOffset,
},
}
for _, c := range cases {
chunk := c.chunkConstructor(d1, d4, false, ChunkLen)
cs, err := chunk.Add(model.SamplePair{
Timestamp: model.Now(),
Value: model.SampleValue(100),
})
if err != nil {
t.Fatalf("Couldn't add sample to empty %s: %s", c.chunkTypeName, err)
}
buf := make([]byte, ChunkLen)
cs[0].MarshalToBuf(buf)
// Corrupt time byte to 0, which is illegal.
buf[c.timeBytesPos] = 0
err = cs[0].UnmarshalFromBuf(buf)
verifyUnmarshallingError(err, c.chunkTypeName, "buf", "invalid number of time bytes")
err = cs[0].Unmarshal(bytes.NewBuffer(buf))
verifyUnmarshallingError(err, c.chunkTypeName, "Reader", "invalid number of time bytes")
// Fix the corruption to go on.
buf[c.timeBytesPos] = byte(d1)
// Corrupt the length to be every possible too-small value
for i := 0; i < c.minHeaderLen; i++ {
binary.LittleEndian.PutUint16(buf[c.chunkLenPos:], uint16(i))
err = cs[0].UnmarshalFromBuf(buf)
verifyUnmarshallingError(err, c.chunkTypeName, "buf", "header size")
err = cs[0].Unmarshal(bytes.NewBuffer(buf))
verifyUnmarshallingError(err, c.chunkTypeName, "Reader", "header size")
}
}
}