added utils, folder structure

.gitignore

@@ -1,2 +1,4 @@
 /target
 Cargo.lock
+
+.vscode

Cargo.toml

@@ -7,3 +7,4 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+xxhrs = { version = "2.0.0", features = [] } #"random_entropy"] }

src/engines/aflengine.rs

@@ -1,16 +1,16 @@
 use std::time;
 
-pub trait RandState {}
-pub trait Executor {}
-pub trait Feedback {}
-pub trait Stage {}
+use crate::utils::Rand;
+use crate::feedbacks::Feedback;
+use crate::stages::Stage;
+use crate::executors::Executor;
+use crate::engines::Engine;
+use crate::monitors::Monitor;
 
-pub trait Monitor {}
+pub struct AflEngine {
 
-pub struct DefaultEngine {
-
-    pub rand: Box<dyn RandState>,
-    pub feedback: Vec<Box<dyn Feedback>>,
+    //pub rand: Box<dyn Rand>,
+    //pub feedback: Vec<Box<dyn Feedback>>,
 
     pub stages: Vec<Box<dyn Stage>>,
     pub current_stage: Box<dyn Stage>,
@@ -25,4 +25,8 @@ pub struct DefaultEngine {
     // TODO: Map
     pub monitors: Vec<Box<dyn Monitor>>,
 
+}
+
+impl Engine for AflEngine {
+
 }

src/engines/mod.rs

@@ -1,4 +1,4 @@
-pub mod engine;
+pub mod aflengine;
 
 pub trait Engine {
 

src/executors/mod.rs

@@ -0,0 +1,2 @@
+
+pub trait Executor {}

src/feedbacks/mod.rs

@@ -0,0 +1 @@
+pub trait Feedback {}

src/inputs/bytes.rs

@@ -2,7 +2,7 @@ use crate::inputs::Input;
 
 use std::io::Error;
 
-#[derive(Debug)]
+#[derive(Clone, Debug, Default)]
 pub struct BytesInput {
     bytes: Vec<u8>,
 }

src/lib.rs

@@ -1,5 +1,11 @@
 pub mod engines;
+pub mod executors;
+pub mod feedbacks;
 pub mod inputs;
+pub mod monitors;
+pub mod mutators;
+pub mod stages;
+pub mod utils;
 
 #[cfg(test)]
 mod tests {

src/main.rs

@@ -1,3 +1,11 @@
+pub mod engines;
+pub mod executors;
+pub mod feedbacks;
+pub mod inputs;
+pub mod monitors;
+pub mod mutators;
+pub mod stages;
+pub mod utils;
 
 fn main() {
     println!("Hello, world!");

src/monitors/mod.rs

@@ -0,0 +1 @@
+pub trait Monitor {}

src/mutators/mod.rs

@@ -0,0 +1,24 @@
+use std::io::Error;
+use crate::inputs::Input;
+use crate::utils::Rand;
+
+pub mod scheduled;
+
+pub trait Mutator {
+
+    //fn rand(&self) -> &Box<dyn Rand>;
+    //fn rand_mut(&self) -> &mut Box<dyn Rand>;
+
+    fn mutate(&mut self, input: &mut dyn Input) -> Result<(), Error> {
+        self.mutate_at((-1) as i32, input)
+    }
+
+    fn mutate_at(&mut self, stage_idx: i32, input: &mut dyn Input) -> Result<(), Error>;
+
+    fn post_exec(&mut self, is_interesting: bool) -> Result<(), Error> {
+        self.post_exec_at((-1) as i32, is_interesting)
+    }
+
+    fn post_exec_at(&mut self, stage_idx: i32, is_interesting: bool) -> Result<(), Error>;
+
+}

src/mutators/scheduled.rs

@@ -0,0 +1,12 @@
+use crate::mutators::Mutator;
+
+pub trait ScheduledMutator: Mutator {
+
+    fn iterations(&self) -> u64 {
+
+        //1 << (1 + self.rand_mut().below(7))
+        return 0;
+
+    }
+
+}

src/stages/mod.rs

@@ -0,0 +1,2 @@
+//! Stages
+pub trait Stage {}

src/utils.rs

@@ -0,0 +1,129 @@
+//! Utility functions for AFL
+
+use std::debug_assert;
+use xxhrs::{XXH3_64};
+
+/// Ways to get random around here
+pub trait Rand {
+
+    // Returns a new, randomly seeded, rand
+    fn new() -> Self;
+    // Sets the seed of this Rand
+    fn set_seed(&mut self, seed: u64);
+    // Gets the next 64 bit value
+    fn next(&mut self) -> u64;
+    // Gets a value below the given 64 bit val (inclusive)
+    fn below(&mut self, upper_bound_excl: u64) -> u64 {
+        if upper_bound_excl <= 1 {
+            return 0;
+        }
+
+        /*
+        Modulo is biased - we don't want our fuzzing to be biased so let's do it
+        right. See
+        https://stackoverflow.com/questions/10984974/why-do-people-say-there-is-modulo-bias-when-using-a-random-number-generator
+        */   
+        let mut unbiased_rnd: u64;
+        loop {
+            unbiased_rnd = self.next();
+            if unbiased_rnd < (u64::MAX - (u64::MAX % upper_bound_excl)) {
+                break;
+            }
+        }
+
+        unbiased_rnd % upper_bound_excl
+
+    }
+
+    // Gets a value between the given lower bound (inclusive) and upper bound (inclusive)
+    fn between(&mut self, lower_bound_incl: u64, upper_bound_incl: u64) -> u64 {
+        debug_assert!(lower_bound_incl < upper_bound_incl);
+        lower_bound_incl + self.below(upper_bound_incl - lower_bound_incl + 1)
+    }
+
+}
+
+const HASH_CONST: u64 = 0xa5b35705;
+
+/// XXH3 Based, hopefully speedy, rnd implementation
+/// 
+#[derive(Copy, Clone, Debug, Default)]
+struct AflRand {
+
+
+    rand_seed: [u64; 4],
+    seeded: bool,
+
+}
+
+impl Rand for AflRand {
+
+    fn new() -> AflRand {
+
+        let mut ret: AflRand = Default::default();
+        ret.set_seed(0); // TODO: Proper random seed?
+        ret
+    }
+
+    fn set_seed(&mut self, seed: u64) {
+        self.rand_seed[0] = XXH3_64::hash_with_seed(HASH_CONST, &seed.to_le_bytes());
+        self.rand_seed[1] = self.rand_seed[0] ^ 0x1234567890abcdef;
+        self.rand_seed[2] = self.rand_seed[0] & 0x0123456789abcdef;
+        self.rand_seed[3] = self.rand_seed[0] | 0x01abcde43f567908;
+
+        self.seeded = true;
+    }
+
+    fn next(&mut self) -> u64 {
+
+        let ret: u64 = self.rand_seed[0].wrapping_add(self.rand_seed[3]).rotate_left(23).wrapping_add(self.rand_seed[0]);
+        let t: u64 = self.rand_seed[1] << 17;
+
+        self.rand_seed[2] ^= self.rand_seed[0];
+        self.rand_seed[3] ^= self.rand_seed[1];
+        self.rand_seed[1] ^= self.rand_seed[2];
+        self.rand_seed[0] ^= self.rand_seed[3];
+
+        self.rand_seed[2] ^= t;
+
+        self.rand_seed[3] = self.rand_seed[3].rotate_left(45);
+
+        return ret;
+
+    }
+
+}
+
+/// Get the next higher power of two
+fn next_pow2(val: u64) -> u64 {
+    // Early exit so we don't have to do a wrapping subtract;
+    if val <= 2 {
+        return val;
+    }
+    let mut out: u64 = val - 1;
+    out |= out >> 1;
+    out |= out >> 2;
+    out |= out >> 4;
+    out |= out >> 8;
+    out |= out >> 16;
+    return out + 1;
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::utils::{AflRand, next_pow2};
+
+    #[test]
+    fn test_rand() {
+        //let rand: AflRand = AflRand::new();
+    }
+
+    #[test]
+    fn test_next_pow2() {
+        assert_eq!(next_pow2(0), 0);
+        assert_eq!(next_pow2(1), 1);
+        assert_eq!(next_pow2(2), 2);
+        assert_eq!(next_pow2(3), 4);
+        assert_eq!(next_pow2(1000), 1024);
+    }
+}