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109 lines
2.8 KiB
Go
109 lines
2.8 KiB
Go
package can
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import (
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"context"
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"fmt"
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"math/rand"
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"strconv"
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"strings"
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"time"
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"github.com/dustin/go-humanize"
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"go.einride.tech/can"
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)
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func (mod *CANModule) fuzzSelectFrame(id string, rng *rand.Rand) (uint64, error) {
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// let's try as an hex number first
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frameID, err := strconv.ParseUint(id, 16, 32)
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if err != nil {
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// not a number, use as node name if we have a dbc
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if mod.dbc.Loaded() {
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fromSender := mod.dbc.MessagesBySender(id)
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if len(fromSender) == 0 {
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return 0, fmt.Errorf("no messages defined in DBC file for node %s, available nodes: %s", id, mod.dbc.Senders())
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}
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idx := rng.Intn(len(fromSender))
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selected := fromSender[idx]
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mod.Info("selected %s > (%d) %s", id, selected.ID, selected.Name)
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frameID = uint64(selected.ID)
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} else {
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// no dbc, just return the error
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return 0, err
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}
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}
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return frameID, nil
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}
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func (mod *CANModule) fuzzGenerateFrame(frameID uint64, size int, rng *rand.Rand) (*can.Frame, error) {
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dataLen := 0
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frameData := ([]byte)(nil)
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// if we have a DBC
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if mod.dbc.Loaded() {
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if message := mod.dbc.MessageById(uint32(frameID)); message != nil {
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mod.Info("using message %s", message.Name)
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dataLen = int(message.Length)
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frameData = make([]byte, dataLen)
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if _, err := rand.Read(frameData); err != nil {
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return nil, err
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}
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} else {
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return nil, fmt.Errorf("message with id %d not found in DBC file, available ids: %v", frameID, strings.Join(mod.dbc.AvailableMessages(), ", "))
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}
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} else {
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if size <= 0 {
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// pick randomly
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dataLen = rng.Intn(int(can.MaxDataLength))
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} else {
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// user selected
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dataLen = size
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}
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frameData = make([]byte, dataLen)
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if _, err := rand.Read(frameData); err != nil {
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return nil, err
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}
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mod.Warning("no dbc loaded, creating frame with %d bytes of random data", dataLen)
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}
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frame := can.Frame{
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ID: uint32(frameID),
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Length: uint8(dataLen),
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IsRemote: false,
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IsExtended: false,
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}
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copy(frame.Data[:], frameData)
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return &frame, nil
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}
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func (mod *CANModule) Fuzz(id string, optSize string) error {
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rncSource := rand.NewSource(time.Now().Unix())
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rng := rand.New(rncSource)
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fuzzSize := 0
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if optSize != "" {
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if num, err := strconv.Atoi(optSize); err != nil {
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return fmt.Errorf("could not parse numeric size from '%s': %v", optSize, err)
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} else if num > 8 {
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return fmt.Errorf("max can frame size is 8, %d given", num)
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} else {
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fuzzSize = num
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}
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}
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if frameID, err := mod.fuzzSelectFrame(id, rng); err != nil {
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return err
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} else if frame, err := mod.fuzzGenerateFrame(frameID, fuzzSize, rng); err != nil {
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return err
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} else {
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mod.Info("injecting %s of CAN frame %d ...",
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humanize.Bytes(uint64(frame.Length)), frame.ID)
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if err := mod.send.TransmitFrame(context.Background(), *frame); err != nil {
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return err
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}
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}
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return nil
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}
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