wafrift_evolution/search/mod.rs
1//! Search algorithms for evolutionary WAF bypass discovery.
2
3use crate::evolution::{Chromosome, GenePool};
4use crate::types::{Budget, EvolutionError, OracleVerdict, SearchStats};
5use rand::rngs::StdRng;
6use std::cmp::Ordering;
7
8/// A candidate requested for evaluation, with a stable evaluation ID.
9#[derive(Debug, Clone)]
10pub struct EvalCandidate {
11 /// Stable ID used to correlate results.
12 pub id: u64,
13 /// The chromosome to evaluate.
14 pub chromosome: Chromosome,
15}
16
17/// Result of submitting evaluations back to the algorithm.
18#[derive(Debug, Clone, Copy, PartialEq, Eq)]
19pub enum SubmitResult {
20 /// The algorithm accepted all results.
21 Accepted,
22 /// Some evaluation IDs were unknown.
23 UnknownIds(usize),
24}
25
26/// Core trait implemented by all search algorithms.
27///
28/// Each algorithm manages its own internal state (population, archive,
29/// temperature, tabu list, etc.). The [`EvolutionEngine`](crate::evolution::EvolutionEngine)
30/// handles caching, budgeting, and batching on top of this trait.
31pub trait SearchAlgorithm: Send + Sync + std::fmt::Debug {
32 /// Algorithm name.
33 fn name(&self) -> &'static str;
34
35 /// Initialize the algorithm with a seed population.
36 fn initialize(&mut self, population: Vec<Chromosome>, gene_pool: &GenePool, rng: &mut StdRng);
37
38 /// Request up to `n` candidates for parallel evaluation.
39 ///
40 /// Returns candidates with stable IDs. The caller evaluates them and
41 /// later calls [`submit_evaluations`](SearchAlgorithm::submit_evaluations).
42 fn request_evaluations(&mut self, n: usize, rng: &mut StdRng) -> Vec<EvalCandidate>;
43
44 /// Submit evaluation results.
45 ///
46 /// The ID in each tuple must match an ID previously returned by
47 /// `request_evaluations`.
48 fn submit_evaluations(&mut self, results: Vec<(u64, OracleVerdict)>);
49
50 /// Check whether the algorithm thinks search should stop.
51 fn should_terminate(&self, stats: &SearchStats, budget: &Budget) -> bool;
52
53 /// Get the best chromosome found so far.
54 fn best(&self) -> Option<&Chromosome>;
55
56 /// Serialize internal state to bytes.
57 fn checkpoint(&self) -> Result<Vec<u8>, EvolutionError>;
58
59 /// Restore internal state from bytes.
60 fn restore(&mut self, bytes: &[u8]) -> Result<(), EvolutionError>;
61}
62
63/// Convert non-finite fitness values into a strict worst-case sentinel.
64///
65/// NaN and +/-inf break partial ordering semantics and can lock algorithms
66/// into never-accept states. Mapping them to `-inf` keeps comparisons total.
67#[must_use]
68pub(crate) fn comparable_fitness(value: f64) -> f64 {
69 if value.is_finite() {
70 value
71 } else {
72 f64::NEG_INFINITY
73 }
74}
75
76#[must_use]
77pub(crate) fn fitness_cmp(a: f64, b: f64) -> Ordering {
78 comparable_fitness(a)
79 .partial_cmp(&comparable_fitness(b))
80 .unwrap_or(Ordering::Equal)
81}
82
83pub mod hill_climb;
84pub mod map_elites;
85pub mod novelty;
86pub mod sim_anneal;
87pub mod tabu;
88
89pub use hill_climb::HillClimbing;
90pub use map_elites::MapElites;
91pub use novelty::NoveltySearch;
92pub use sim_anneal::SimulatedAnnealing;
93pub use tabu::TabuSearch;