add fuzzer

Cargo.lock

@@ -1,6 +1,6 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 3
+version = 4
 
 [[package]]
 name = "addr2line"
@@ -66,6 +66,15 @@ dependencies = [
  "windows-sys 0.52.0",
 ]
 
+[[package]]
+name = "arbitrary"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7d5a26814d8dcb93b0e5a0ff3c6d80a8843bafb21b39e8e18a6f05471870e110"
+dependencies = [
+ "derive_arbitrary",
+]
+
 [[package]]
 name = "asn1"
 version = "0.16.2"
@@ -149,6 +158,8 @@ version = "1.1.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "72db2f7947ecee9b03b510377e8bb9077afa27176fdbff55c51027e976fdcc48"
 dependencies = [
+ "jobserver",
+ "libc",
  "shlex",
 ]
 
@@ -255,6 +266,17 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "derive_arbitrary"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "67e77553c4162a157adbf834ebae5b415acbecbeafc7a74b0e886657506a7611"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "diesel"
 version = "2.2.2"
@@ -640,6 +662,15 @@ version = "1.0.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "49f1f14873335454500d59611f1cf4a4b0f786f9ac11f4312a78e4cf2566695b"
 
+[[package]]
+name = "jobserver"
+version = "0.1.32"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "48d1dbcbbeb6a7fec7e059840aa538bd62aaccf972c7346c4d9d2059312853d0"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "js-sys"
 version = "0.3.70"
@@ -655,6 +686,17 @@ version = "0.2.158"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d8adc4bb1803a324070e64a98ae98f38934d91957a99cfb3a43dcbc01bc56439"
 
+[[package]]
+name = "libfuzzer-sys"
+version = "0.4.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a96cfd5557eb82f2b83fed4955246c988d331975a002961b07c81584d107e7f7"
+dependencies = [
+ "arbitrary",
+ "cc",
+ "once_cell",
+]
+
 [[package]]
 name = "linux-raw-sys"
 version = "0.4.14"
@@ -1614,6 +1656,7 @@ checksum = "ced3678a2879b30306d323f4542626697a464a97c0a07c9aebf7ebca65cd4dde"
 name = "zns"
 version = "0.1.0"
 dependencies = [
+ "arbitrary",
  "base64",
  "int-enum",
  "thiserror",
@@ -1645,3 +1688,11 @@ dependencies = [
  "tokio",
  "zns",
 ]
+
+[[package]]
+name = "zns-fuzz"
+version = "0.0.0"
+dependencies = [
+ "libfuzzer-sys",
+ "zns",
+]

Cargo.toml

@@ -5,4 +5,5 @@ members = [
     "zns",
     "zns-cli",
     "zns-daemon",
+    "fuzz"
 ]

fuzz/.gitignore

@@ -0,0 +1,4 @@
+target
+corpus
+artifacts
+coverage

fuzz/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "zns-fuzz"
+version = "0.0.0"
+publish = false
+edition = "2021"
+
+[package.metadata]
+cargo-fuzz = true
+
+[dependencies]
+libfuzzer-sys = "0.4"
+zns = {path = "../zns", features = ["arbitrary"]}
+
+[[bin]]
+name = "parser"
+path = "fuzz_targets/parser.rs"
+test = false
+doc = false
+bench = false

fuzz/cov.sh

@@ -0,0 +1,42 @@
+#!/bin/env bash
+set -e
+
+# Check if the correct number of arguments is provided
+if [ "$#" -ne 2 ]; then
+    echo "Usage: $0 <llvm-cov> <fuzz_target>"
+    exit 1
+fi
+
+# Assign the first argument to the fuzz_target variable
+COMMAND=$1
+FUZZ_TARGET=$2
+
+
+if ! command -v $(COMMAND) &> /dev/null; then
+    echo "llvm-cov could not be found, please install LLVM."
+    exit 1
+fi
+
+if ! command -v rustfilt &> /dev/null; then
+    echo "rustfilt could not be found, please install rustfilt."
+    exit 1
+fi
+
+cargo fuzz coverage "$FUZZ_TARGET"
+
+TARGET_DIR="target/x86_64-unknown-linux-gnu/coverage/x86_64-unknown-linux-gnu/release"
+PROF_DATA="coverage/$FUZZ_TARGET/coverage.profdata"
+OUTPUT_FILE="coverage/index.html"
+
+if [ ! -f "$PROF_DATA" ]; then
+    echo "Coverage data file $PROF_DATA not found."
+    exit 1
+fi
+
+$COMMAND show "$TARGET_DIR/$FUZZ_TARGET" --format=html \
+                                         -Xdemangler=rustfilt \
+                                         --ignore-filename-regex="\.cargo" \
+                                         -instr-profile="$PROF_DATA" \
+                                         > "$OUTPUT_FILE"
+
+echo "Coverage report generated as $OUTPUT_FILE"

fuzz/flake.lock

@@ -0,0 +1,82 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1726560853,
+        "narHash": "sha256-X6rJYSESBVr3hBoH0WbKE5KvhPU5bloyZ2L4K60/fPQ=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "c1dfcf08411b08f6b8615f7d8971a2bfa81d5e8a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1728241625,
+        "narHash": "sha256-yumd4fBc/hi8a9QgA9IT8vlQuLZ2oqhkJXHPKxH/tRw=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "c31898adf5a8ed202ce5bea9f347b1c6871f32d1",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs",
+        "rust-overlay": "rust-overlay"
+      }
+    },
+    "rust-overlay": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1728354625,
+        "narHash": "sha256-r+Sa1NRRT7LXKzCaVaq75l1GdZcegODtF06uaxVVVbI=",
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "rev": "d216ade5a0091ce60076bf1f8bc816433a1fc5da",
+        "type": "github"
+      },
+      "original": {
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "type": "github"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

fuzz/flake.nix

@@ -0,0 +1,31 @@
+{
+  description = "flake for fuzzer as it needs nightly";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+    rust-overlay = {
+      url = "github:oxalica/rust-overlay";
+      inputs.nixpkgs.follows = "nixpkgs";
+      inputs.flake-utils.follows = "flake-utils";
+    };
+  };
+  outputs = {self,  nixpkgs, flake-utils, rust-overlay, ... }:
+  flake-utils.lib.eachDefaultSystem (system:
+  let
+    overlays = [ (import rust-overlay) ];
+    pkgs = import nixpkgs {
+      inherit system overlays;
+    };
+  in
+  with pkgs;
+  {
+    devShell = mkShell {
+      buildInputs = [
+        (rust-bin.nightly.latest.default.override { extensions = [ "llvm-tools-preview" ]; })
+        cargo-fuzz
+        rustfilt
+      ];
+    };
+  });
+}

fuzz/fuzz_targets/parser.rs

@@ -0,0 +1,9 @@
+#![no_main]
+
+use libfuzzer_sys::fuzz_target;
+use zns::{parser::FromBytes, reader::Reader, structs::Message};
+
+fuzz_target!(|data: &[u8]| {
+    let mut reader = Reader::new(data);
+    let _ = Message::from_bytes(&mut reader);
+});

zns/Cargo.toml

@@ -11,6 +11,7 @@ test-utils = []
 base64 = "0.22.0"
 int-enum = "1.1"
 thiserror = "1.0"
+arbitrary = { version = "^1.3.2", optional = true, features = ["derive"] }
 
 [dev-dependencies]
 zns = { path = ".", features = ["test-utils"] }

zns/src/labelstring.rs

@@ -1,6 +1,7 @@
 use std::fmt::Display;
 
 #[derive(Debug, Clone)]
+#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
 pub struct LabelString(Vec<String>);
 
 pub fn labels_equal(vec1: &LabelString, vec2: &LabelString) -> bool {

zns/src/reader.rs

@@ -66,12 +66,12 @@ impl<'a> Reader<'a> {
     }
 
     pub fn seek(&self, position: usize) -> Result<Self> {
-        if position >= self.position - 2 {
+        if self.position < 2 || position >= self.position - 2 {
             Err(ZNSError::Reader {
                 message: String::from("Seeking into the future is not allowed!!"),
             })
         } else {
-            let mut reader = Reader::new(&self.buffer[..self.position]);
+            let mut reader = Reader::new(&self.buffer[..self.position - 1]);
             reader.position = position;
             Ok(reader)
         }
@@ -126,7 +126,7 @@ mod tests {
 
         let new_reader = reader.seek(1);
         assert!(new_reader.is_ok());
-        assert_eq!(new_reader.unwrap().unread_bytes(), 10);
+        assert_eq!(new_reader.unwrap().unread_bytes(), 9);
 
         let new_reader = reader.seek(100);
         assert!(new_reader.is_err());

zns/src/structs.rs

@@ -3,6 +3,7 @@ use int_enum::IntEnum;
 use crate::labelstring::LabelString;
 
 #[derive(Debug, Clone, PartialEq)]
+#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
 pub enum Type {
     Type(RRType),
     Other(u16),
@@ -10,6 +11,7 @@ pub enum Type {
 
 #[repr(u16)]
 #[derive(Debug, Clone, PartialEq, IntEnum)]
+#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
 pub enum RRType {
     A = 1,
     SOA = 6,
@@ -20,6 +22,7 @@ pub enum RRType {
 }
 
 #[derive(Debug, Clone, PartialEq)]
+#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
 pub enum Class {
     Class(RRClass),
     Other(u16),
@@ -27,6 +30,7 @@ pub enum Class {
 
 #[repr(u16)]
 #[derive(Debug, Clone, PartialEq, IntEnum)]
+#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
 pub enum RRClass {
     IN = 1,
     NONE = 254,
@@ -56,6 +60,7 @@ pub enum Opcode {
 }
 
 #[derive(Debug, Clone, PartialEq)]
+#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
 pub struct Question {
     pub qname: LabelString,
     pub qtype: Type,   // NOTE: should be QTYPE, right now not really needed
@@ -63,6 +68,7 @@ pub struct Question {
 }
 
 #[derive(Debug, Clone, PartialEq)]
+#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
 pub struct Header {
     pub id: u16,
     pub flags: u16, // |QR|   Opcode  |AA|TC|RD|RA|   Z    |   RCODE   | ; 1 | 4 | 1 | 1 | 1 | 1 | 3 | 4
@@ -73,6 +79,7 @@ pub struct Header {
 }
 
 #[derive(Debug, Clone, PartialEq)]
+#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
 pub struct Message {
     pub header: Header,
     pub question: Vec<Question>,
@@ -82,6 +89,7 @@ pub struct Message {
 }
 
 #[derive(Debug, Clone, PartialEq)]
+#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
 pub struct RR {
     pub name: LabelString,
     pub _type: Type,