Add TargetBytesConverter to allow Nautilus for ForkserverExecutor (#2630)

* Add TargetBytesConverter to allow Nautilus for ForkserverExecutor

* ci

* ci

* More

* fmt

.github/workflows/build_and_test.yml

@@ -272,6 +272,7 @@ jobs:
           - ./fuzzers/structure_aware/baby_fuzzer_multi
           - ./fuzzers/structure_aware/baby_fuzzer_custom_input
           - ./fuzzers/structure_aware/baby_fuzzer_nautilus
+          - ./fuzzers/structure_aware/forkserver_simple_nautilus
 
           # In-process
           - ./fuzzers/fuzz_anything/cargo_fuzz

.gitignore

@@ -6,6 +6,7 @@ vendor
 
 .DS_Store
 .env
+.vscode
 
 *.test
 *.tmp

fuzzers/structure_aware/baby_fuzzer_nautilus/src/main.rs

@@ -76,13 +76,9 @@ pub fn main() {
     )
     .unwrap();
 
-    if state
-        .metadata_map()
-        .get::<NautilusChunksMetadata>()
-        .is_none()
-    {
-        state.add_metadata(NautilusChunksMetadata::new("/tmp/".into()));
-    }
+    let _ = state.metadata_or_insert_with::<NautilusChunksMetadata>(|| {
+        NautilusChunksMetadata::new("/tmp/".into())
+    });
 
     // The Monitor trait define how the fuzzer stats are reported to the user
     let monitor = SimpleMonitor::new(|s| println!("{s}"));
@@ -139,9 +135,11 @@ pub fn main() {
     */
 
     // Generate 8 initial inputs
-    state
-        .generate_initial_inputs_forced(&mut fuzzer, &mut executor, &mut generator, &mut mgr, 8)
-        .expect("Failed to generate the initial corpus");
+    if state.must_load_initial_inputs() {
+        state
+            .generate_initial_inputs_forced(&mut fuzzer, &mut executor, &mut generator, &mut mgr, 8)
+            .expect("Failed to generate the initial corpus");
+    }
 
     // Setup a mutational stage with a basic bytes mutator
     let mutator = StdScheduledMutator::with_max_stack_pow(

fuzzers/structure_aware/forkserver_simple_nautilus/.gitignore

@@ -0,0 +1 @@
+forkserver_simple

fuzzers/structure_aware/forkserver_simple_nautilus/Cargo.toml

@@ -0,0 +1,24 @@
+[package]
+name = "forkserver_simple"
+version = "0.13.2"
+authors = ["tokatoka <tokazerkje@outlook.com>"]
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[profile.dev]
+panic = "abort"
+
+[profile.release]
+panic = "abort"
+lto = true
+codegen-units = 1
+opt-level = 3
+
+[dependencies]
+clap = { version = "4.5.18", features = ["derive"] }
+env_logger = "0.11.5"
+libafl = { path = "../../../libafl", features = ["std", "derive"] }
+libafl_bolts = { path = "../../../libafl_bolts" }
+log = { version = "0.4.22", features = ["release_max_level_info"] }
+nix = { version = "0.29.0", features = ["signal"] }

fuzzers/structure_aware/forkserver_simple_nautilus/README.md

@@ -0,0 +1,13 @@
+# Simple Forkserver Fuzzer
+
+This is a simple example fuzzer to fuzz a executable instrumented by afl-cc.
+## Usage
+You can build this example by `cargo build --release`.  
+This downloads AFLplusplus/AFLplusplus and compiles the example harness program in src/program.c with afl-cc  
+
+## Run
+After you build it you can run  
+`cp ./target/release/forkserver_simple .` to copy the fuzzer into this directory,  
+and you can run  
+`taskset -c 1 ./forkserver_simple ./target/release/program ./corpus/ -t 1000` to run the fuzzer.
+`taskset` binds this process to a specific core to improve the throughput.  

fuzzers/structure_aware/forkserver_simple_nautilus/build.rs

@@ -0,0 +1,59 @@
+use std::{
+    env,
+    path::Path,
+    process::{exit, Command},
+};
+
+const AFL_URL: &str = "https://github.com/AFLplusplus/AFLplusplus";
+
+fn main() {
+    if cfg!(windows) {
+        println!("cargo:warning=No support for windows yet.");
+        exit(0);
+    }
+
+    env::remove_var("DEBUG");
+    let cwd = env::current_dir().unwrap().to_string_lossy().to_string();
+
+    let afl = format!("{}/AFLplusplus", &cwd);
+    let afl_cc = format!("{}/AFLplusplus/afl-cc", &cwd);
+
+    let afl_path = Path::new(&afl);
+    let afl_cc_path = Path::new(&afl_cc);
+
+    if !afl_path.is_dir() {
+        println!("cargo:warning=AFL++ not found, downloading...");
+        Command::new("git")
+            .arg("clone")
+            .arg(AFL_URL)
+            .status()
+            .unwrap();
+    }
+
+    if !afl_cc_path.is_file() {
+        let mut afl_cc_make = Command::new("make");
+        afl_cc_make.arg("all").current_dir(afl_path);
+        if let Ok(llvm_config) = env::var("LLVM_CONFIG") {
+            if !llvm_config.is_empty() {
+                afl_cc_make.env("LLVM_CONFIG", llvm_config);
+            }
+        }
+        afl_cc_make.status().unwrap();
+    }
+
+    let mut compile_command = Command::new(afl_cc_path);
+    compile_command
+        .args(["src/program.c", "-o"])
+        .arg(format!("{cwd}/target/release/program"));
+
+    if let Ok(llvm_config) = env::var("LLVM_CONFIG") {
+        if !llvm_config.is_empty() {
+            compile_command.env("LLVM_CONFIG", llvm_config);
+        }
+    }
+
+    compile_command.status().unwrap();
+
+    println!("cargo:rerun-if-changed=build.rs");
+    println!("cargo:rerun-if-changed=src/");
+}

fuzzers/structure_aware/forkserver_simple_nautilus/corpus/testfile

@@ -0,0 +1 @@
+aaa

fuzzers/structure_aware/forkserver_simple_nautilus/src/main.rs

@@ -0,0 +1,227 @@
+use core::time::Duration;
+use std::path::PathBuf;
+
+use clap::Parser;
+use libafl::{
+    corpus::{InMemoryCorpus, OnDiskCorpus},
+    events::SimpleEventManager,
+    executors::{forkserver::ForkserverExecutor, HasObservers},
+    feedback_and_fast, feedback_or,
+    feedbacks::{
+        CrashFeedback, MaxMapFeedback, NautilusChunksMetadata, NautilusFeedback, TimeFeedback,
+    },
+    fuzzer::{Fuzzer, StdFuzzer},
+    generators::{NautilusContext, NautilusGenerator},
+    inputs::{NautilusInput, NautilusTargetBytesConverter},
+    monitors::SimpleMonitor,
+    mutators::{
+        NautilusRandomMutator, NautilusRecursionMutator, NautilusSpliceMutator,
+        StdScheduledMutator, Tokens,
+    },
+    observers::{CanTrack, HitcountsMapObserver, StdMapObserver, TimeObserver},
+    schedulers::{IndexesLenTimeMinimizerScheduler, QueueScheduler},
+    stages::mutational::StdMutationalStage,
+    state::StdState,
+    HasMetadata,
+};
+use libafl_bolts::{
+    current_nanos,
+    rands::StdRand,
+    shmem::{ShMem, ShMemProvider, UnixShMemProvider},
+    tuples::{tuple_list, Handled},
+    AsSliceMut, Truncate,
+};
+use nix::sys::signal::Signal;
+
+/// The commandline args this fuzzer accepts
+#[derive(Debug, Parser)]
+#[command(
+    name = "forkserver_simple",
+    about = "This is a simple example fuzzer to fuzz a executable instrumented by afl-cc, using Nautilus grammar.",
+    author = "tokatoka <tokazerkje@outlook.com>, dmnk <domenukk@gmail.com>"
+)]
+struct Opt {
+    #[arg(
+        help = "The instrumented binary we want to fuzz",
+        name = "EXEC",
+        required = true
+    )]
+    executable: String,
+
+    #[arg(
+        help = "Timeout for each individual execution, in milliseconds",
+        short = 't',
+        long = "timeout",
+        default_value = "1200"
+    )]
+    timeout: u64,
+
+    #[arg(
+        help = "If not set, the child's stdout and stderror will be redirected to /dev/null",
+        short = 'd',
+        long = "debug-child",
+        default_value = "false"
+    )]
+    debug_child: bool,
+
+    #[arg(
+        help = "Arguments passed to the target",
+        name = "arguments",
+        num_args(1..),
+        allow_hyphen_values = true,
+    )]
+    arguments: Vec<String>,
+
+    #[arg(
+        help = "Signal used to stop child",
+        short = 's',
+        long = "signal",
+        value_parser = str::parse::<Signal>,
+        default_value = "SIGKILL"
+    )]
+    signal: Signal,
+
+    #[arg(help = "The nautilus grammar file", short)]
+    grammar: PathBuf,
+}
+
+#[allow(clippy::similar_names)]
+pub fn main() {
+    env_logger::init();
+    const MAP_SIZE: usize = 65536;
+
+    let opt = Opt::parse();
+
+    let mut shmem_provider = UnixShMemProvider::new().unwrap();
+
+    // The coverage map shared between observer and executor
+    let mut shmem = shmem_provider.new_shmem(MAP_SIZE).unwrap();
+    // let the forkserver know the shmid
+    shmem.write_to_env("__AFL_SHM_ID").unwrap();
+    let shmem_buf = shmem.as_slice_mut();
+
+    // Create an observation channel using the signals map
+    let edges_observer = unsafe {
+        HitcountsMapObserver::new(StdMapObserver::new("shared_mem", shmem_buf)).track_indices()
+    };
+
+    // Create an observation channel to keep track of the execution time
+    let time_observer = TimeObserver::new("time");
+
+    let context = NautilusContext::from_file(15, opt.grammar);
+
+    // Feedback to rate the interestingness of an input
+    // This one is composed by two Feedbacks in OR
+    let mut feedback = feedback_or!(
+        // New maximization map feedback linked to the edges observer and the feedback state
+        MaxMapFeedback::new(&edges_observer),
+        // Time feedback, this one does not need a feedback state
+        TimeFeedback::new(&time_observer),
+        // Nautilus context
+        NautilusFeedback::new(&context),
+    );
+
+    // A feedback to choose if an input is a solution or not
+    // We want to do the same crash deduplication that AFL does
+    let mut objective = feedback_and_fast!(
+        // Must be a crash
+        CrashFeedback::new(),
+        // Take it only if trigger new coverage over crashes
+        // Uses `with_name` to create a different history from the `MaxMapFeedback` in `feedback` above
+        MaxMapFeedback::with_name("mapfeedback_metadata_objective", &edges_observer)
+    );
+
+    // create a State from scratch
+    let mut state = StdState::new(
+        // RNG
+        StdRand::with_seed(current_nanos()),
+        // Corpus that will be evolved, we keep it in memory for performance
+        InMemoryCorpus::<NautilusInput>::new(),
+        // Corpus in which we store solutions (crashes in this example),
+        // on disk so the user can get them after stopping the fuzzer
+        OnDiskCorpus::new(PathBuf::from("./crashes")).unwrap(),
+        // States of the feedbacks.
+        // The feedbacks can report the data that should persist in the State.
+        &mut feedback,
+        // Same for objective feedbacks
+        &mut objective,
+    )
+    .unwrap();
+
+    let _ = state.metadata_or_insert_with::<NautilusChunksMetadata>(|| {
+        NautilusChunksMetadata::new("/tmp/".into())
+    });
+
+    // The Monitor trait define how the fuzzer stats are reported to the user
+    let monitor = SimpleMonitor::new(|s| println!("{s}"));
+
+    // The event manager handle the various events generated during the fuzzing loop
+    // such as the notification of the addition of a new item to the corpus
+    let mut mgr = SimpleEventManager::new(monitor);
+
+    // A minimization+queue policy to get testcasess from the corpus
+    let scheduler = IndexesLenTimeMinimizerScheduler::new(&edges_observer, QueueScheduler::new());
+
+    // A fuzzer with feedbacks and a corpus scheduler
+    let mut fuzzer = StdFuzzer::new(scheduler, feedback, objective);
+
+    // If we should debug the child
+    let debug_child = opt.debug_child;
+
+    // Create the executor for the forkserver
+    let args = opt.arguments;
+
+    let observer_ref = edges_observer.handle();
+
+    let mut tokens = Tokens::new();
+    let mut executor = ForkserverExecutor::builder()
+        .program(opt.executable)
+        .debug_child(debug_child)
+        .shmem_provider(&mut shmem_provider)
+        .autotokens(&mut tokens)
+        .parse_afl_cmdline(args)
+        .coverage_map_size(MAP_SIZE)
+        .timeout(Duration::from_millis(opt.timeout))
+        .kill_signal(opt.signal)
+        .target_bytes_converter(NautilusTargetBytesConverter::new(&context))
+        .build(tuple_list!(time_observer, edges_observer))
+        .unwrap();
+
+    if let Some(dynamic_map_size) = executor.coverage_map_size() {
+        executor.observers_mut()[&observer_ref]
+            .as_mut()
+            .truncate(dynamic_map_size);
+    }
+
+    let mut generator = NautilusGenerator::new(&context);
+
+    if state.must_load_initial_inputs() {
+        state
+            .generate_initial_inputs(&mut fuzzer, &mut executor, &mut generator, &mut mgr, 8)
+            .expect("Failed to generate inputs");
+    }
+
+    state.add_metadata(tokens);
+
+    // Setup a mutational stage with a basic bytes mutator
+    let mutator = StdScheduledMutator::with_max_stack_pow(
+        tuple_list!(
+            NautilusRandomMutator::new(&context),
+            NautilusRandomMutator::new(&context),
+            NautilusRandomMutator::new(&context),
+            NautilusRandomMutator::new(&context),
+            NautilusRandomMutator::new(&context),
+            NautilusRandomMutator::new(&context),
+            NautilusRecursionMutator::new(&context),
+            NautilusSpliceMutator::new(&context),
+            NautilusSpliceMutator::new(&context),
+            NautilusSpliceMutator::new(&context),
+        ),
+        2,
+    );
+    let mut stages = tuple_list!(StdMutationalStage::new(mutator));
+
+    fuzzer
+        .fuzz_loop(&mut stages, &mut executor, &mut state, &mut mgr)
+        .expect("Error in the fuzzing loop");
+}

fuzzers/structure_aware/forkserver_simple_nautilus/src/program.c

@@ -0,0 +1,35 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+// The following line is needed for shared memeory testcase fuzzing
+__AFL_FUZZ_INIT();
+
+void vuln(char *buf) {
+  if (strcmp(buf, "vuln") == 0) { abort(); }
+}
+
+int main(int argc, char **argv) {
+  FILE *file = stdin;
+  if (argc > 1) { file = fopen(argv[1], "rb"); }
+
+  // The following three lines are for normal fuzzing.
+  /*
+  char buf[16];
+  char* p = fgets(buf, 16, file);
+  buf[15] = 0;
+  */
+
+  // The following line is also needed for shared memory testcase fuzzing
+  unsigned char *buf = __AFL_FUZZ_TESTCASE_BUF;
+
+  printf("input: %s\n", buf);
+  if (buf[0] == 'b') {
+    if (buf[1] == 'a') {
+      if (buf[2] == 'd') { abort(); }
+    }
+  }
+  vuln(buf);
+
+  return 0;
+}

libafl/Cargo.toml

@@ -27,6 +27,7 @@ rustc-args = ["--cfg", "docsrs"]
 
 [features]
 default = [
+  "nautilus",
   "std",
   "derive",
   "llmp_compression",

libafl/src/executors/forkserver.rs

@@ -42,7 +42,9 @@ use crate::observers::{
 };
 use crate::{
     executors::{Executor, ExitKind, HasObservers},
-    inputs::{HasTargetBytes, Input, UsesInput},
+    inputs::{
+        BytesInput, HasTargetBytes, Input, NopTargetBytesConverter, TargetBytesConverter, UsesInput,
+    },
     mutators::Tokens,
     observers::{MapObserver, Observer, ObserversTuple},
     state::{HasExecutions, State, UsesState},
@@ -70,9 +72,9 @@ const FS_OPT_SHDMEM_FUZZ: i32 = 0x01000000_u32 as i32;
 const FS_NEW_OPT_SHDMEM_FUZZ: i32 = 2_u32 as i32;
 
 #[allow(clippy::cast_possible_wrap)]
-const FS_NEW_OPT_AUTODICT: i32 = 0x00000800_u32 as i32;
+const FS_NEW_OPT_AUTODTCT: i32 = 0x00000800_u32 as i32;
 #[allow(clippy::cast_possible_wrap)]
-const FS_OPT_AUTODICT: i32 = 0x10000000_u32 as i32;
+const FS_OPT_AUTODTCT: i32 = 0x10000000_u32 as i32;
 
 #[allow(clippy::cast_possible_wrap)]
 const FS_ERROR_MAP_SIZE: i32 = 1_u32 as i32;
@@ -584,13 +586,14 @@ impl Forkserver {
 ///
 /// Shared memory feature is also available, but you have to set things up in your code.
 /// Please refer to AFL++'s docs. <https://github.com/AFLplusplus/AFLplusplus/blob/stable/instrumentation/README.persistent_mode.md>
-pub struct ForkserverExecutor<OT, S, SP>
+pub struct ForkserverExecutor<TC, OT, S, SP>
 where
     SP: ShMemProvider,
 {
     target: OsString,
     args: Vec<OsString>,
     input_file: InputFile,
+    target_bytes_converter: TC,
     uses_shmem_testcase: bool,
     forkserver: Forkserver,
     observers: OT,
@@ -605,8 +608,9 @@ where
     crash_exitcode: Option<i8>,
 }
 
-impl<OT, S, SP> Debug for ForkserverExecutor<OT, S, SP>
+impl<TC, OT, S, SP> Debug for ForkserverExecutor<TC, OT, S, SP>
 where
+    TC: Debug,
     OT: Debug,
     SP: ShMemProvider,
 {
@@ -615,6 +619,7 @@ where
             .field("target", &self.target)
             .field("args", &self.args)
             .field("input_file", &self.input_file)
+            .field("target_bytes_converter", &self.target_bytes_converter)
             .field("uses_shmem_testcase", &self.uses_shmem_testcase)
             .field("forkserver", &self.forkserver)
             .field("observers", &self.observers)
@@ -623,15 +628,17 @@ where
     }
 }
 
-impl ForkserverExecutor<(), (), UnixShMemProvider> {
+impl ForkserverExecutor<(), (), (), UnixShMemProvider> {
     /// Builder for `ForkserverExecutor`
     #[must_use]
-    pub fn builder() -> ForkserverExecutorBuilder<'static, UnixShMemProvider> {
+    pub fn builder(
+    ) -> ForkserverExecutorBuilder<'static, NopTargetBytesConverter<BytesInput>, UnixShMemProvider>
+    {
         ForkserverExecutorBuilder::new()
     }
 }
 
-impl<OT, S, SP> ForkserverExecutor<OT, S, SP>
+impl<TC, OT, S, SP> ForkserverExecutor<TC, OT, S, SP>
 where
     OT: ObserversTuple<S::Input, S>,
     S: UsesInput,
@@ -671,7 +678,7 @@ where
 /// The builder for `ForkserverExecutor`
 #[derive(Debug)]
 #[allow(clippy::struct_excessive_bools)]
-pub struct ForkserverExecutorBuilder<'a, SP> {
+pub struct ForkserverExecutorBuilder<'a, TC, SP> {
     program: Option<OsString>,
     arguments: Vec<OsString>,
     envs: Vec<(OsString, OsString)>,
@@ -691,9 +698,10 @@ pub struct ForkserverExecutorBuilder<'a, SP> {
     #[cfg(feature = "regex")]
     asan_obs: Option<Handle<AsanBacktraceObserver>>,
     crash_exitcode: Option<i8>,
+    target_bytes_converter: TC,
 }
 
-impl<'a, SP> ForkserverExecutorBuilder<'a, SP>
+impl<'a, TC, SP> ForkserverExecutorBuilder<'a, TC, SP>
 where
     SP: ShMemProvider,
 {
@@ -703,11 +711,12 @@ where
     /// in case no input file is specified.
     /// If `debug_child` is set, the child will print to `stdout`/`stderr`.
     #[allow(clippy::pedantic)]
-    pub fn build<OT, S>(&mut self, observers: OT) -> Result<ForkserverExecutor<OT, S, SP>, Error>
+    pub fn build<OT, S>(mut self, observers: OT) -> Result<ForkserverExecutor<TC, OT, S, SP>, Error>
     where
         OT: ObserversTuple<S::Input, S>,
         S: UsesInput,
-        S::Input: Input + HasTargetBytes,
+        S::Input: Input,
+        TC: TargetBytesConverter,
         SP: ShMemProvider,
     {
         let (forkserver, input_file, map) = self.build_helper()?;
@@ -758,16 +767,17 @@ where
                 .clone()
                 .unwrap_or(AsanBacktraceObserver::default().handle()),
             crash_exitcode: self.crash_exitcode,
+            target_bytes_converter: self.target_bytes_converter,
         })
     }
 
     /// Builds `ForkserverExecutor` downsizing the coverage map to fit exaclty the AFL++ map size.
     #[allow(clippy::pedantic)]
     pub fn build_dynamic_map<A, MO, OT, S>(
-        &mut self,
+        mut self,
         mut map_observer: A,
         other_observers: OT,
-    ) -> Result<ForkserverExecutor<(A, OT), S, SP>, Error>
+    ) -> Result<ForkserverExecutor<TC, (A, OT), S, SP>, Error>
     where
         MO: MapObserver + Truncate, // TODO maybe enforce Entry = u8 for the cov map
         A: Observer<S::Input, S> + AsMut<MO>,
@@ -822,6 +832,7 @@ where
                 .clone()
                 .unwrap_or(AsanBacktraceObserver::default().handle()),
             crash_exitcode: self.crash_exitcode,
+            target_bytes_converter: self.target_bytes_converter,
         })
     }
 
@@ -957,7 +968,7 @@ where
             }
         }
 
-        if status & FS_NEW_OPT_AUTODICT != 0 {
+        if status & FS_NEW_OPT_AUTODTCT != 0 {
             // Here unlike shmem input fuzzing, we are forced to read things
             // hence no self.autotokens.is_some() to check if we proceed
             let autotokens_size = forkserver.read_st().map_err(|err| {
@@ -1010,14 +1021,14 @@ where
             self.set_map_size(fsrv_map_size)?;
         }
 
-        // Only with SHMEM or AUTODICT we can send send_status back or it breaks!
+        // Only with SHMEM or AUTODTCT we can send send_status back or it breaks!
         // If forkserver is responding, we then check if there's any option enabled.
         // We'll send 4-bytes message back to the forkserver to tell which features to use
         // The forkserver is listening to our response if either shmem fuzzing is enabled or auto dict is enabled
         // <https://github.com/AFLplusplus/AFLplusplus/blob/147654f8715d237fe45c1657c87b2fe36c4db22a/instrumentation/afl-compiler-rt.o.c#L1026>
         if status & FS_OPT_ENABLED == FS_OPT_ENABLED
             && (status & FS_OPT_SHDMEM_FUZZ == FS_OPT_SHDMEM_FUZZ
-                || status & FS_OPT_AUTODICT == FS_OPT_AUTODICT)
+                || status & FS_OPT_AUTODTCT == FS_OPT_AUTODTCT)
         {
             let mut send_status = FS_OPT_ENABLED;
 
@@ -1027,9 +1038,9 @@ where
                 self.uses_shmem_testcase = true;
             }
 
-            if (status & FS_OPT_AUTODICT == FS_OPT_AUTODICT) && self.autotokens.is_some() {
-                log::info!("Using AUTODICT feature");
-                send_status |= FS_OPT_AUTODICT;
+            if (status & FS_OPT_AUTODTCT == FS_OPT_AUTODTCT) && self.autotokens.is_some() {
+                log::info!("Using AUTODTCT feature");
+                send_status |= FS_OPT_AUTODTCT;
             }
 
             if send_status != FS_OPT_ENABLED {
@@ -1042,7 +1053,7 @@ where
                     )));
                 }
 
-                if (send_status & FS_OPT_AUTODICT) == FS_OPT_AUTODICT {
+                if (send_status & FS_OPT_AUTODTCT) == FS_OPT_AUTODTCT {
                     let dict_size = forkserver.read_st().map_err(|err| {
                         Error::illegal_state(format!("Reading from forkserver failed: {err:?}"))
                     })?;
@@ -1318,7 +1329,7 @@ where
     }
 }
 
-impl<'a> ForkserverExecutorBuilder<'a, UnixShMemProvider> {
+impl<'a> ForkserverExecutorBuilder<'a, NopTargetBytesConverter<BytesInput>, UnixShMemProvider> {
     /// Creates a new `AFL`-style [`ForkserverExecutor`] with the given target, arguments and observers.
     /// This is the builder for `ForkserverExecutor`
     /// This Forkserver will attempt to provide inputs over shared mem when `shmem_provider` is given.
@@ -1326,7 +1337,8 @@ impl<'a> ForkserverExecutorBuilder<'a, UnixShMemProvider> {
     /// in case no input file is specified.
     /// If `debug_child` is set, the child will print to `stdout`/`stderr`.
     #[must_use]
-    pub fn new() -> ForkserverExecutorBuilder<'a, UnixShMemProvider> {
+    pub fn new(
+    ) -> ForkserverExecutorBuilder<'a, NopTargetBytesConverter<BytesInput>, UnixShMemProvider> {
         ForkserverExecutorBuilder {
             program: None,
             arguments: vec![],
@@ -1346,14 +1358,17 @@ impl<'a> ForkserverExecutorBuilder<'a, UnixShMemProvider> {
             timeout: None,
             asan_obs: None,
             crash_exitcode: None,
+            target_bytes_converter: NopTargetBytesConverter::new(),
         }
     }
+}
 
+impl<'a, TC> ForkserverExecutorBuilder<'a, TC, UnixShMemProvider> {
     /// Shmem provider for forkserver's shared memory testcase feature.
     pub fn shmem_provider<SP: ShMemProvider>(
         self,
         shmem_provider: &'a mut SP,
-    ) -> ForkserverExecutorBuilder<'a, SP> {
+    ) -> ForkserverExecutorBuilder<'a, TC, SP> {
         ForkserverExecutorBuilder {
             // Set the new provider
             shmem_provider: Some(shmem_provider),
@@ -1375,22 +1390,57 @@ impl<'a> ForkserverExecutorBuilder<'a, UnixShMemProvider> {
             timeout: self.timeout,
             asan_obs: self.asan_obs,
             crash_exitcode: self.crash_exitcode,
+            target_bytes_converter: self.target_bytes_converter,
         }
     }
 }
 
-impl Default for ForkserverExecutorBuilder<'_, UnixShMemProvider> {
+impl<'a, TC, SP> ForkserverExecutorBuilder<'a, TC, SP> {
+    /// Shmem provider for forkserver's shared memory testcase feature.
+    pub fn target_bytes_converter<TC2: TargetBytesConverter>(
+        self,
+        target_bytes_converter: TC2,
+    ) -> ForkserverExecutorBuilder<'a, TC2, SP> {
+        ForkserverExecutorBuilder {
+            // Set the new provider
+            shmem_provider: self.shmem_provider,
+            // Copy all other values from the old Builder
+            program: self.program,
+            arguments: self.arguments,
+            envs: self.envs,
+            debug_child: self.debug_child,
+            use_stdin: self.use_stdin,
+            uses_shmem_testcase: self.uses_shmem_testcase,
+            is_persistent: self.is_persistent,
+            is_deferred_frksrv: self.is_deferred_frksrv,
+            autotokens: self.autotokens,
+            input_filename: self.input_filename,
+            map_size: self.map_size,
+            max_input_size: self.max_input_size,
+            min_input_size: self.min_input_size,
+            kill_signal: self.kill_signal,
+            timeout: self.timeout,
+            asan_obs: self.asan_obs,
+            crash_exitcode: self.crash_exitcode,
+            target_bytes_converter: target_bytes_converter,
+        }
+    }
+}
+
+impl Default
+    for ForkserverExecutorBuilder<'_, NopTargetBytesConverter<BytesInput>, UnixShMemProvider>
+{
     fn default() -> Self {
         Self::new()
     }
 }
 
-impl<EM, OT, S, SP, Z> Executor<EM, Z> for ForkserverExecutor<OT, S, SP>
+impl<EM, TC, OT, S, SP, Z> Executor<EM, Z> for ForkserverExecutor<TC, OT, S, SP>
 where
     OT: ObserversTuple<S::Input, S>,
     SP: ShMemProvider,
     S: State + HasExecutions,
-    S::Input: HasTargetBytes,
+    TC: TargetBytesConverter<Input = S::Input>,
     EM: UsesState<State = S>,
     Z: UsesState<State = S>,
 {
@@ -1408,7 +1458,7 @@ where
 
         let last_run_timed_out = self.forkserver.last_run_timed_out_raw();
 
-        let mut input_bytes = input.target_bytes();
+        let mut input_bytes = self.target_bytes_converter.to_target_bytes(input);
         let mut input_size = input_bytes.as_slice().len();
         if input_size > self.max_input_size {
             // Truncate like AFL++ does
@@ -1497,7 +1547,7 @@ where
     }
 }
 
-impl<OT, S, SP> UsesState for ForkserverExecutor<OT, S, SP>
+impl<TC, OT, S, SP> UsesState for ForkserverExecutor<TC, OT, S, SP>
 where
     S: State,
     SP: ShMemProvider,
@@ -1505,7 +1555,7 @@ where
     type State = S;
 }
 
-impl<OT, S, SP> HasObservers for ForkserverExecutor<OT, S, SP>
+impl<TC, OT, S, SP> HasObservers for ForkserverExecutor<TC, OT, S, SP>
 where
     OT: ObserversTuple<S::Input, S>,
     S: State,

libafl/src/inputs/mod.rs

@@ -91,9 +91,9 @@ pub trait Input: Clone + Serialize + serde::de::DeserializeOwned + Debug {
 /// Convert between two input types with a state
 pub trait InputConverter: Debug {
     /// Source type
-    type From: Input;
+    type From;
     /// Destination type
-    type To: Input;
+    type To;
 
     /// Convert the src type to the dest
     fn convert(&mut self, input: Self::From) -> Result<Self::To, Error>;
@@ -342,3 +342,42 @@ where
         (self.convert_cb)(input)
     }
 }
+
+/// A converter that converts from `input` to target bytes
+pub trait TargetBytesConverter {
+    /// The input
+    type Input;
+
+    /// Create target bytes
+    fn to_target_bytes<'a>(&mut self, input: &'a Self::Input) -> OwnedSlice<'a, u8>;
+}
+
+/// Simply gets the target bytes out from a [`HasTargetBytes`] type.
+#[derive(Debug)]
+pub struct NopTargetBytesConverter<I> {
+    phantom: PhantomData<I>,
+}
+
+impl<I> NopTargetBytesConverter<I> {
+    /// Create a new [`NopTargetBytesConverter`]
+    #[must_use]
+    pub fn new() -> NopTargetBytesConverter<I> {
+        Self {
+            phantom: PhantomData,
+        }
+    }
+}
+
+impl<I> Default for NopTargetBytesConverter<I> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl<I: HasTargetBytes> TargetBytesConverter for NopTargetBytesConverter<I> {
+    type Input = I;
+
+    fn to_target_bytes<'a>(&mut self, input: &'a Self::Input) -> OwnedSlice<'a, u8> {
+        input.target_bytes()
+    }
+}

libafl/src/inputs/nautilus.rs

@@ -5,9 +5,10 @@ use alloc::{rc::Rc, string::String, vec::Vec};
 use core::cell::RefCell;
 use std::hash::{Hash, Hasher};
 
-use libafl_bolts::HasLen;
+use libafl_bolts::{ownedref::OwnedSlice, HasLen};
 use serde::{Deserialize, Serialize};
 
+use super::TargetBytesConverter;
 use crate::{
     common::nautilus::grammartec::{
         newtypes::NodeId,
@@ -137,3 +138,28 @@ impl InputConverter for NautilusToBytesInputConverter<'_> {
         Ok(BytesInput::new(bytes))
     }
 }
+
+/// A converter to convert a nautilus context to target bytes
+#[derive(Debug)]
+pub struct NautilusTargetBytesConverter<'a> {
+    /// The Nautilus Context
+    ctx: &'a NautilusContext,
+}
+
+impl<'a> NautilusTargetBytesConverter<'a> {
+    /// Create a new [`NautilusTargetBytesConverter`]
+    #[must_use]
+    pub fn new(ctx: &'a NautilusContext) -> NautilusTargetBytesConverter<'a> {
+        NautilusTargetBytesConverter { ctx }
+    }
+}
+
+impl TargetBytesConverter for NautilusTargetBytesConverter<'_> {
+    type Input = NautilusInput;
+
+    fn to_target_bytes<'a>(&mut self, input: &'a Self::Input) -> OwnedSlice<'a, u8> {
+        let mut bytes = Vec::new();
+        input.unparse(self.ctx, &mut bytes);
+        OwnedSlice::from(bytes)
+    }
+}