chore: update bincode to 2.0

Follow the official migration guide for upgrading with serde support,
described in [1]

[1]: https://github.com/bincode-org/bincode/blob/trunk/docs/migration_guide.md#migrating-with-serde

Signed-off-by: Patrick Roy <[email protected]>

Author: roypat

Cargo.lock

@@ -9,12 +9,6 @@ use vmm::seccomp::{BpfThreadMap, DeserializationError, deserialize_binary, get_e
 
 const THREAD_CATEGORIES: [&str; 3] = ["vmm", "api", "vcpu"];
 
-// This byte limit is passed to `bincode` to guard against a potential memory
-// allocation DOS caused by binary filters that are too large.
-// This limit can be safely determined since the maximum length of a BPF
-// filter is 4096 instructions and Firecracker has a finite number of threads.
-const DESERIALIZATION_BYTES_LIMIT: Option<u64> = Some(100_000);
-
 /// Error retrieving seccomp filters.
 #[derive(Debug, thiserror::Error, displaydoc::Display)]
 pub enum FilterError {
@@ -72,15 +66,13 @@ pub fn get_filters(config: SeccompConfig) -> Result<BpfThreadMap, FilterError> {
 fn get_default_filters() -> Result<BpfThreadMap, FilterError> {
     // Retrieve, at compile-time, the serialized binary filter generated with seccompiler.
     let bytes: &[u8] = include_bytes!(concat!(env!("OUT_DIR"), "/seccomp_filter.bpf"));
-    let map = deserialize_binary(bytes, DESERIALIZATION_BYTES_LIMIT)
-        .map_err(FilterError::Deserialization)?;
+    let map = deserialize_binary(bytes).map_err(FilterError::Deserialization)?;
     filter_thread_categories(map)
 }
 
 /// Retrieve custom seccomp filters.
 fn get_custom_filters<R: Read + Debug>(reader: R) -> Result<BpfThreadMap, FilterError> {
-    let map = deserialize_binary(BufReader::new(reader), DESERIALIZATION_BYTES_LIMIT)
-        .map_err(FilterError::Deserialization)?;
+    let map = deserialize_binary(BufReader::new(reader)).map_err(FilterError::Deserialization)?;
     filter_thread_categories(map)
 }
 

src/firecracker/src/seccomp.rs

@@ -16,7 +16,7 @@ path = "src/bin.rs"
 bench = false
 
 [dependencies]
-bincode = "1.2.1"
+bincode = { version = "2.0.1", features = ["serde"] }
 clap = { version = "4.5.32", features = ["derive", "string"] }
 displaydoc = "0.2.5"
 libc = "0.2.171"

src/seccompiler/Cargo.toml

@@ -8,7 +8,9 @@ use std::os::fd::{AsRawFd, FromRawFd};
 use std::os::unix::fs::MetadataExt;
 use std::str::FromStr;
 
-use bincode::Error as BincodeError;
+use bincode::config;
+use bincode::config::{Configuration, Fixint, Limit, LittleEndian};
+use bincode::error::EncodeError as BincodeError;
 
 mod bindings;
 use bindings::*;
@@ -17,6 +19,18 @@ pub mod types;
 pub use types::*;
 use zerocopy::IntoBytes;
 
+// This byte limit is passed to `bincode` to guard against a potential memory
+// allocation DOS caused by binary filters that are too large.
+// This limit can be safely determined since the maximum length of a BPF
+// filter is 4096 instructions and Firecracker has a finite number of threads.
+const DESERIALIZATION_BYTES_LIMIT: usize = 100_000;
+
+pub const BINCODE_CONFIG: Configuration<LittleEndian, Fixint, Limit<DESERIALIZATION_BYTES_LIMIT>> =
+    config::standard()
+        .with_fixed_int_encoding()
+        .with_limit::<DESERIALIZATION_BYTES_LIMIT>()
+        .with_little_endian();
+
 /// Binary filter compilation errors.
 #[derive(Debug, thiserror::Error, displaydoc::Display)]
 pub enum CompilationError {
@@ -174,8 +188,9 @@ pub fn compile_bpf(
         bpf_map.insert(name.clone(), bpf);
     }
 
-    let output_file = File::create(out_path).map_err(CompilationError::OutputCreate)?;
+    let mut output_file = File::create(out_path).map_err(CompilationError::OutputCreate)?;
 
-    bincode::serialize_into(output_file, &bpf_map).map_err(CompilationError::BincodeSerialize)?;
+    bincode::encode_into_std_write(&bpf_map, &mut output_file, BINCODE_CONFIG)
+        .map_err(CompilationError::BincodeSerialize)?;
     Ok(())
 }

src/seccompiler/src/lib.rs

@@ -14,7 +14,7 @@ aes-gcm =  { version = "0.10.1", default-features = false, features = ["aes"] }
 arrayvec = { version = "0.7.6", optional = true }
 aws-lc-rs = { version = "1.12.6", features = ["bindgen"] }
 base64 = "0.22.1"
-bincode = "1.2.1"
+bincode = { version = "2.0.1", features = ["serde"] }
 bitflags = "2.9.0"
 crc64 = "2.0.0"
 derive_more = { version = "2.0.1", default-features = false, features = ["from", "display"] }

src/vmm/Cargo.toml

@@ -10,7 +10,8 @@ use std::{fmt, io};
 
 use aes_gcm::{AeadInPlace, Aes256Gcm, Key, KeyInit, Nonce};
 use base64::Engine;
-use bincode::{DefaultOptions, Error as BincodeError, Options};
+use bincode::config;
+use bincode::config::{Configuration, Fixint, Limit, LittleEndian};
 use serde::{Deserialize, Serialize};
 use utils::time::{ClockType, get_time_ms};
 
@@ -45,6 +46,12 @@ const TOKEN_LENGTH_LIMIT: usize = 70;
 /// too much memory when deserializing tokens.
 const DESERIALIZATION_BYTES_LIMIT: usize = std::mem::size_of::<Token>();
 
+const BINCODE_CONFIG: Configuration<LittleEndian, Fixint, Limit<DESERIALIZATION_BYTES_LIMIT>> =
+    config::standard()
+        .with_fixed_int_encoding()
+        .with_limit::<DESERIALIZATION_BYTES_LIMIT>()
+        .with_little_endian();
+
 #[rustfmt::skip]
 #[derive(Debug, thiserror::Error, displaydoc::Display)]
 pub enum MmdsTokenError {
@@ -57,7 +64,7 @@ pub enum MmdsTokenError {
     /// Invalid time to live value provided for token: {0}. Please provide a value between {MIN_TOKEN_TTL_SECONDS:} and {MAX_TOKEN_TTL_SECONDS:}.
     InvalidTtlValue(u32),
     /// Bincode serialization failed: {0}.
-    Serialization(#[from] BincodeError),
+    Serialization(#[from] bincode::error::EncodeError),
     /// Failed to encrypt token.
     TokenEncryption,
 }
@@ -287,7 +294,7 @@ impl Token {
 
     /// Encode token structure into a string using base64 encoding.
     fn base64_encode(&self) -> Result<String, MmdsTokenError> {
-        let token_bytes: Vec<u8> = bincode::serialize(self)?;
+        let token_bytes: Vec<u8> = bincode::serde::encode_to_vec(self, BINCODE_CONFIG)?;
 
         // Encode token structure bytes into base64.
         Ok(base64::engine::general_purpose::STANDARD.encode(token_bytes))
@@ -299,12 +306,9 @@ impl Token {
             .decode(encoded_token)
             .map_err(|_| MmdsTokenError::ExpiryExtraction)?;
 
-        let token: Token = DefaultOptions::new()
-            .with_fixint_encoding()
-            .allow_trailing_bytes()
-            .with_limit(DESERIALIZATION_BYTES_LIMIT as u64)
-            .deserialize(&token_bytes)
-            .map_err(|_| MmdsTokenError::ExpiryExtraction)?;
+        let token: Token = bincode::serde::decode_from_slice(&token_bytes, BINCODE_CONFIG)
+            .map_err(|_| MmdsTokenError::ExpiryExtraction)?
+            .0;
         Ok(token)
     }
 }
@@ -518,45 +522,4 @@ mod tests {
         assert!(!token_authority.is_valid(&token0));
         assert!(!token_authority.is_valid(&token1));
     }
-
-    #[test]
-    fn test_error_display() {
-        assert_eq!(
-            MmdsTokenError::EntropyPool(io::Error::from_raw_os_error(0)).to_string(),
-            format!(
-                "Failed to extract entropy from /dev/urandom entropy pool: {}.",
-                io::Error::from_raw_os_error(0)
-            )
-        );
-
-        assert_eq!(
-            MmdsTokenError::ExpiryExtraction.to_string(),
-            "Failed to extract expiry value from token."
-        );
-
-        assert_eq!(
-            MmdsTokenError::InvalidState.to_string(),
-            "Invalid token authority state."
-        );
-
-        assert_eq!(
-            MmdsTokenError::InvalidTtlValue(0).to_string(),
-            format!(
-                "Invalid time to live value provided for token: 0. Please provide a value between \
-                 {} and {}.",
-                MIN_TOKEN_TTL_SECONDS, MAX_TOKEN_TTL_SECONDS
-            )
-        );
-
-        assert_eq!(
-            MmdsTokenError::Serialization(BincodeError::new(bincode::ErrorKind::SizeLimit))
-                .to_string(),
-            "Bincode serialization failed: the size limit has been reached."
-        );
-
-        assert_eq!(
-            MmdsTokenError::TokenEncryption.to_string(),
-            "Failed to encrypt token."
-        );
-    }
 }

src/vmm/src/mmds/token.rs

@@ -5,7 +5,20 @@ use std::collections::HashMap;
 use std::io::Read;
 use std::sync::Arc;
 
-use bincode::{DefaultOptions, Options};
+use bincode::config;
+use bincode::config::{Configuration, Fixint, Limit, LittleEndian};
+
+// This byte limit is passed to `bincode` to guard against a potential memory
+// allocation DOS caused by binary filters that are too large.
+// This limit can be safely determined since the maximum length of a BPF
+// filter is 4096 instructions and Firecracker has a finite number of threads.
+const DESERIALIZATION_BYTES_LIMIT: usize = 100_000;
+
+const BINCODE_CONFIG: Configuration<LittleEndian, Fixint, Limit<DESERIALIZATION_BYTES_LIMIT>> =
+    config::standard()
+        .with_fixed_int_encoding()
+        .with_limit::<DESERIALIZATION_BYTES_LIMIT>()
+        .with_little_endian();
 
 /// Each BPF instruction is 8 bytes long and 4 byte aligned.
 /// This alignment needs to be satisfied in order for a BPF code to be accepted
@@ -22,7 +35,7 @@ pub type BpfProgramRef<'a> = &'a [BpfInstruction];
 pub type BpfThreadMap = HashMap<String, Arc<BpfProgram>>;
 
 /// Binary filter deserialization errors.
-pub type DeserializationError = bincode::Error;
+pub type DeserializationError = bincode::error::DecodeError;
 
 /// Retrieve empty seccomp filters.
 pub fn get_empty_filters() -> BpfThreadMap {
@@ -34,19 +47,8 @@ pub fn get_empty_filters() -> BpfThreadMap {
 }
 
 /// Deserialize binary with bpf filters
-pub fn deserialize_binary<R: Read>(
-    reader: R,
-    bytes_limit: Option<u64>,
-) -> Result<BpfThreadMap, DeserializationError> {
-    let result = match bytes_limit {
-        Some(limit) => DefaultOptions::new()
-            .with_fixint_encoding()
-            .allow_trailing_bytes()
-            .with_limit(limit)
-            .deserialize_from::<R, HashMap<String, BpfProgram>>(reader),
-        // No limit is the default.
-        None => bincode::deserialize_from::<R, HashMap<String, BpfProgram>>(reader),
-    }?;
+pub fn deserialize_binary<R: Read>(mut reader: R) -> Result<BpfThreadMap, DeserializationError> {
+    let result: HashMap<String, _> = bincode::decode_from_std_read(&mut reader, BINCODE_CONFIG)?;
 
     Ok(result
         .into_iter()
@@ -134,49 +136,28 @@ mod tests {
     #[test]
     fn test_deserialize_binary() {
         // Malformed bincode binary.
-        {
-            let data = "adassafvc".to_string();
-            deserialize_binary(data.as_bytes(), None).unwrap_err();
-        }
+        let data = "adassafvc".to_string();
+        deserialize_binary(data.as_bytes()).unwrap_err();
 
         // Test that the binary deserialization is correct, and that the thread keys
         // have been lowercased.
-        {
-            let bpf_prog = vec![0; 2];
-            let mut filter_map: HashMap<String, BpfProgram> = HashMap::new();
-            filter_map.insert("VcpU".to_string(), bpf_prog.clone());
-            let bytes = bincode::serialize(&filter_map).unwrap();
-
-            let mut expected_res = BpfThreadMap::new();
-            expected_res.insert("vcpu".to_string(), Arc::new(bpf_prog));
-            assert_eq!(deserialize_binary(&bytes[..], None).unwrap(), expected_res);
-        }
-
-        // Test deserialization with binary_limit.
-        {
-            let bpf_prog = vec![0; 2];
-
-            let mut filter_map: HashMap<String, BpfProgram> = HashMap::new();
-            filter_map.insert("t1".to_string(), bpf_prog.clone());
-
-            let bytes = bincode::serialize(&filter_map).unwrap();
-
-            // Binary limit too low.
-            assert!(matches!(
-                deserialize_binary(&bytes[..], Some(20)).unwrap_err(),
-                error
-                    if error.to_string() == "the size limit has been reached"
-            ));
-
-            let mut expected_res = BpfThreadMap::new();
-            expected_res.insert("t1".to_string(), Arc::new(bpf_prog));
-
-            // Correct binary limit.
-            assert_eq!(
-                deserialize_binary(&bytes[..], Some(50)).unwrap(),
-                expected_res
-            );
-        }
+        let bpf_prog = vec![0; 2];
+        let mut filter_map: HashMap<String, BpfProgram> = HashMap::new();
+        filter_map.insert("VcpU".to_string(), bpf_prog.clone());
+        let bytes = bincode::serde::encode_to_vec(&filter_map, BINCODE_CONFIG).unwrap();
+
+        let mut expected_res = BpfThreadMap::new();
+        expected_res.insert("vcpu".to_string(), Arc::new(bpf_prog));
+        assert_eq!(deserialize_binary(&bytes[..]).unwrap(), expected_res);
+
+        let bpf_prog = vec![0; DESERIALIZATION_BYTES_LIMIT + 1];
+        let mut filter_map: HashMap<String, BpfProgram> = HashMap::new();
+        filter_map.insert("VcpU".to_string(), bpf_prog.clone());
+        let bytes = bincode::serde::encode_to_vec(&filter_map, BINCODE_CONFIG).unwrap();
+        assert!(matches!(
+            deserialize_binary(&bytes[..]).unwrap_err(),
+            bincode::error::DecodeError::LimitExceeded
+        ));
     }
 
     #[test]