bettercap/modules/can/can_fuzz.go
2024-08-16 13:30:26 +02:00

93 lines
2.1 KiB
Go

package can
import (
"context"
"fmt"
"math/rand"
"strconv"
"strings"
"time"
"github.com/dustin/go-humanize"
"go.einride.tech/can"
"go.einride.tech/can/pkg/descriptor"
)
func (mod *CANModule) Fuzz(id string) error {
rncSource := rand.NewSource(time.Now().Unix())
rng := rand.New(rncSource)
// let's try as number first
frameID, err := strconv.Atoi(id)
dataLen := 0
frameData := ([]byte)(nil)
if err != nil {
if mod.dbc != nil {
// not a number, use as node name
fromSender := make([]*descriptor.Message, 0)
for _, msg := range mod.dbc.Messages {
if msg.SenderNode == id {
fromSender = append(fromSender, msg)
}
}
if len(fromSender) == 0 {
return fmt.Errorf("no messages defined in DBC file for node %s", id)
}
idx := rng.Intn(len(fromSender))
selected := fromSender[idx]
mod.Info("selected %s > (%d) %s", id, selected.ID, selected.Name)
frameID = int(selected.ID)
} else {
return err
}
}
// if we have a DBC
if mod.dbc != nil {
if message, found := mod.dbc.Message(uint32(frameID)); found {
mod.Info("found as %s", message.Name)
dataLen = int(message.Length)
frameData = make([]byte, dataLen)
if _, err := rand.Read(frameData); err != nil {
return err
}
} else {
avail := []string{}
for _, msg := range mod.dbc.Messages {
avail = append(avail, fmt.Sprintf("%d (%s)", msg.ID, msg.Name))
}
return fmt.Errorf("message with id %d not found in DBC file, available ids: %v", frameID, strings.Join(avail, ", "))
}
} else {
dataLen = rng.Intn(int(can.MaxDataLength))
frameData = make([]byte, dataLen)
if _, err := rand.Read(frameData); err != nil {
return err
}
mod.Warning("no can.dbc_path is set, creating frame with %d bytes of random data", dataLen)
}
frame := can.Frame{
ID: uint32(frameID),
Length: uint8(dataLen),
IsRemote: false,
IsExtended: false,
}
copy(frame.Data[:], frameData)
mod.Info("injecting %s of CAN frame %d ...",
humanize.Bytes(uint64(frame.Length)), frame.ID)
if err := mod.send.TransmitFrame(context.Background(), frame); err != nil {
return err
}
return nil
}