mirror of
https://codeberg.org/forgejo/forgejo.git
synced 2024-08-28 15:37:55 +02:00
162 lines
5.1 KiB
Go
162 lines
5.1 KiB
Go
|
// Copyright (c) 2016 Marty Schoch
|
||
|
|
||
|
// 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 smat
|
||
|
|
||
|
import (
|
||
|
"bufio"
|
||
|
"bytes"
|
||
|
"fmt"
|
||
|
"io"
|
||
|
"io/ioutil"
|
||
|
"log"
|
||
|
"math/rand"
|
||
|
)
|
||
|
|
||
|
// Logger is a configurable logger used by this package
|
||
|
// by default output is discarded
|
||
|
var Logger = log.New(ioutil.Discard, "smat ", log.LstdFlags)
|
||
|
|
||
|
// Context is a container for any user state
|
||
|
type Context interface{}
|
||
|
|
||
|
// State is a function which describes which action to perform in the event
|
||
|
// that a particular byte is seen
|
||
|
type State func(next byte) ActionID
|
||
|
|
||
|
// PercentAction describes the frequency with which an action should occur
|
||
|
// for example: Action{Percent:10, Action:DonateMoney} means that 10% of
|
||
|
// the time you should donate money.
|
||
|
type PercentAction struct {
|
||
|
Percent int
|
||
|
Action ActionID
|
||
|
}
|
||
|
|
||
|
// Action is any function which returns the next state to transition to
|
||
|
// it can optionally mutate the provided context object
|
||
|
// if any error occurs, it may return an error which will abort execution
|
||
|
type Action func(Context) (State, error)
|
||
|
|
||
|
// ActionID is a unique identifier for an action
|
||
|
type ActionID int
|
||
|
|
||
|
// NopAction does nothing and simply continues to the next input
|
||
|
var NopAction ActionID = -1
|
||
|
|
||
|
// ActionMap is a mapping form ActionID to Action
|
||
|
type ActionMap map[ActionID]Action
|
||
|
|
||
|
func (a ActionMap) findSetupTeardown(setup, teardown ActionID) (Action, Action, error) {
|
||
|
setupFunc, ok := a[setup]
|
||
|
if !ok {
|
||
|
return nil, nil, ErrSetupMissing
|
||
|
}
|
||
|
teardownFunc, ok := a[teardown]
|
||
|
if !ok {
|
||
|
return nil, nil, ErrTeardownMissing
|
||
|
}
|
||
|
return setupFunc, teardownFunc, nil
|
||
|
}
|
||
|
|
||
|
// Fuzz runs the fuzzing state machine with the provided context
|
||
|
// first, the setup action is executed unconditionally
|
||
|
// the start state is determined by this action
|
||
|
// actionMap is a lookup table for all actions
|
||
|
// the data byte slice determines all future state transitions
|
||
|
// finally, the teardown action is executed unconditionally for cleanup
|
||
|
func Fuzz(ctx Context, setup, teardown ActionID, actionMap ActionMap, data []byte) int {
|
||
|
reader := bytes.NewReader(data)
|
||
|
err := runReader(ctx, setup, teardown, actionMap, reader, nil)
|
||
|
if err != nil {
|
||
|
panic(err)
|
||
|
}
|
||
|
return 1
|
||
|
}
|
||
|
|
||
|
// Longevity runs the state machine with the provided context
|
||
|
// first, the setup action is executed unconditionally
|
||
|
// the start state is determined by this action
|
||
|
// actionMap is a lookup table for all actions
|
||
|
// random bytes are generated to determine all future state transitions
|
||
|
// finally, the teardown action is executed unconditionally for cleanup
|
||
|
func Longevity(ctx Context, setup, teardown ActionID, actionMap ActionMap, seed int64, closeChan chan struct{}) error {
|
||
|
source := rand.NewSource(seed)
|
||
|
return runReader(ctx, setup, teardown, actionMap, rand.New(source), closeChan)
|
||
|
}
|
||
|
|
||
|
var (
|
||
|
// ErrSetupMissing is returned when the setup action cannot be found
|
||
|
ErrSetupMissing = fmt.Errorf("setup action missing")
|
||
|
// ErrTeardownMissing is returned when the teardown action cannot be found
|
||
|
ErrTeardownMissing = fmt.Errorf("teardown action missing")
|
||
|
// ErrClosed is returned when the closeChan was closed to cancel the op
|
||
|
ErrClosed = fmt.Errorf("closed")
|
||
|
// ErrActionNotPossible is returned when an action is encountered in a
|
||
|
// FuzzCase that is not possible in the current state
|
||
|
ErrActionNotPossible = fmt.Errorf("action not possible in state")
|
||
|
)
|
||
|
|
||
|
func runReader(ctx Context, setup, teardown ActionID, actionMap ActionMap, r io.Reader, closeChan chan struct{}) error {
|
||
|
setupFunc, teardownFunc, err := actionMap.findSetupTeardown(setup, teardown)
|
||
|
if err != nil {
|
||
|
return err
|
||
|
}
|
||
|
Logger.Printf("invoking setup action")
|
||
|
state, err := setupFunc(ctx)
|
||
|
if err != nil {
|
||
|
return err
|
||
|
}
|
||
|
defer func() {
|
||
|
Logger.Printf("invoking teardown action")
|
||
|
_, _ = teardownFunc(ctx)
|
||
|
}()
|
||
|
|
||
|
reader := bufio.NewReader(r)
|
||
|
for next, err := reader.ReadByte(); err == nil; next, err = reader.ReadByte() {
|
||
|
select {
|
||
|
case <-closeChan:
|
||
|
return ErrClosed
|
||
|
default:
|
||
|
actionID := state(next)
|
||
|
action, ok := actionMap[actionID]
|
||
|
if !ok {
|
||
|
Logger.Printf("no such action defined, continuing")
|
||
|
continue
|
||
|
}
|
||
|
Logger.Printf("invoking action - %d", actionID)
|
||
|
state, err = action(ctx)
|
||
|
if err != nil {
|
||
|
Logger.Printf("it was action %d that returned err %v", actionID, err)
|
||
|
return err
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
return err
|
||
|
}
|
||
|
|
||
|
// PercentExecute interprets the next byte as a random value and normalizes it
|
||
|
// to values 0-99, it then looks to see which action should be execued based
|
||
|
// on the action distributions
|
||
|
func PercentExecute(next byte, pas ...PercentAction) ActionID {
|
||
|
percent := int(99 * int(next) / 255)
|
||
|
|
||
|
sofar := 0
|
||
|
for _, pa := range pas {
|
||
|
sofar = sofar + pa.Percent
|
||
|
if percent < sofar {
|
||
|
return pa.Action
|
||
|
}
|
||
|
|
||
|
}
|
||
|
return NopAction
|
||
|
}
|