solana/core/src/entry.rs

689 lines
23 KiB
Rust

//! The `entry` module is a fundamental building block of Proof of History. It contains a
//! unique ID that is the hash of the Entry before it, plus the hash of the
//! transactions within it. Entries cannot be reordered, and its field `num_hashes`
//! represents an approximate amount of time since the last Entry was created.
use crate::packet::{Blob, SharedBlob, BLOB_DATA_SIZE};
use crate::poh::Poh;
use crate::result::Result;
use bincode::{deserialize, serialize_into, serialized_size};
use chrono::prelude::Utc;
use rayon::prelude::*;
use solana_budget_api::budget_transaction::BudgetTransaction;
use solana_sdk::hash::Hash;
use solana_sdk::pubkey::Pubkey;
use solana_sdk::signature::{Keypair, KeypairUtil};
use solana_sdk::transaction::Transaction;
use solana_vote_api::vote_instruction::Vote;
use solana_vote_api::vote_transaction::VoteTransaction;
use std::borrow::Borrow;
use std::io::Cursor;
use std::mem::size_of;
use std::sync::mpsc::{Receiver, Sender};
use std::sync::{Arc, RwLock};
pub type EntrySender = Sender<Vec<Entry>>;
pub type EntryReceiver = Receiver<Vec<Entry>>;
/// Each Entry contains three pieces of data. The `num_hashes` field is the number
/// of hashes performed since the previous entry. The `hash` field is the result
/// of hashing `hash` from the previous entry `num_hashes` times. The `transactions`
/// field points to Transactions that took place shortly before `hash` was generated.
///
/// If you divide `num_hashes` by the amount of time it takes to generate a new hash, you
/// get a duration estimate since the last Entry. Since processing power increases
/// over time, one should expect the duration `num_hashes` represents to decrease proportionally.
/// An upper bound on Duration can be estimated by assuming each hash was generated by the
/// world's fastest processor at the time the entry was recorded. Or said another way, it
/// is physically not possible for a shorter duration to have occurred if one assumes the
/// hash was computed by the world's fastest processor at that time. The hash chain is both
/// a Verifiable Delay Function (VDF) and a Proof of Work (not to be confused with Proof of
/// Work consensus!)
#[derive(Serialize, Deserialize, Debug, PartialEq, Eq, Clone)]
pub struct Entry {
/// The number of hashes since the previous Entry ID.
pub num_hashes: u64,
/// The SHA-256 hash `num_hashes` after the previous Entry ID.
pub hash: Hash,
/// An unordered list of transactions that were observed before the Entry ID was
/// generated. They may have been observed before a previous Entry ID but were
/// pushed back into this list to ensure deterministic interpretation of the ledger.
pub transactions: Vec<Transaction>,
}
impl Entry {
/// Creates the next Entry `num_hashes` after `start_hash`.
pub fn new(prev_hash: &Hash, num_hashes: u64, transactions: Vec<Transaction>) -> Self {
let entry = {
if num_hashes == 0 && transactions.is_empty() {
Entry {
num_hashes: 0,
hash: *prev_hash,
transactions,
}
} else if num_hashes == 0 {
// If you passed in transactions, but passed in num_hashes == 0, then
// next_hash will generate the next hash and set num_hashes == 1
let hash = next_hash(prev_hash, 1, &transactions);
Entry {
num_hashes: 1,
hash,
transactions,
}
} else {
// Otherwise, the next Entry `num_hashes` after `start_hash`.
// If you wanted a tick for instance, then pass in num_hashes = 1
// and transactions = empty
let hash = next_hash(prev_hash, num_hashes, &transactions);
Entry {
num_hashes,
hash,
transactions,
}
}
};
let size = Entry::serialized_size(&entry.transactions[..]);
if size > BLOB_DATA_SIZE as u64 {
panic!(
"Serialized entry size too large: {} ({} transactions):",
size,
entry.transactions.len()
);
}
entry
}
pub fn to_shared_blob(&self) -> SharedBlob {
let blob = self.to_blob();
Arc::new(RwLock::new(blob))
}
pub fn to_blob(&self) -> Blob {
let mut blob = Blob::default();
let pos = {
let mut out = Cursor::new(blob.data_mut());
serialize_into(&mut out, &self).expect("failed to serialize output");
out.position() as usize
};
blob.set_size(pos);
blob
}
/// Estimate serialized_size of Entry without creating an Entry.
pub fn serialized_size(transactions: &[Transaction]) -> u64 {
let txs_size: u64 = transactions
.iter()
.map(|tx| tx.serialized_size().unwrap())
.sum();
// num_hashes + hash + txs
(2 * size_of::<u64>() + size_of::<Hash>()) as u64 + txs_size
}
pub fn num_will_fit(transactions: &[Transaction]) -> usize {
if transactions.is_empty() {
return 0;
}
let mut num = transactions.len();
let mut upper = transactions.len();
let mut lower = 1; // if one won't fit, we have a lot of TODOs
let mut next = transactions.len(); // optimistic
loop {
debug!(
"num {}, upper {} lower {} next {} transactions.len() {}",
num,
upper,
lower,
next,
transactions.len()
);
if Self::serialized_size(&transactions[..num]) <= BLOB_DATA_SIZE as u64 {
next = (upper + num) / 2;
lower = num;
debug!("num {} fits, maybe too well? trying {}", num, next);
} else {
next = (lower + num) / 2;
upper = num;
debug!("num {} doesn't fit! trying {}", num, next);
}
// same as last time
if next == num {
debug!("converged on num {}", num);
break;
}
num = next;
}
num
}
/// Creates the next Tick Entry `num_hashes` after `start_hash`.
pub fn new_mut(
start_hash: &mut Hash,
num_hashes: &mut u64,
transactions: Vec<Transaction>,
) -> Self {
let entry = Self::new(start_hash, *num_hashes, transactions);
*start_hash = entry.hash;
*num_hashes = 0;
assert!(serialized_size(&entry).unwrap() <= BLOB_DATA_SIZE as u64);
entry
}
/// Creates a Entry from the number of hashes `num_hashes`
/// since the previous transaction and that resulting `hash`.
#[cfg(test)]
pub fn new_tick(num_hashes: u64, hash: &Hash) -> Self {
Entry {
num_hashes,
hash: *hash,
transactions: vec![],
}
}
/// Verifies self.hash is the result of hashing a `start_hash` `self.num_hashes` times.
/// If the transaction is not a Tick, then hash that as well.
pub fn verify(&self, start_hash: &Hash) -> bool {
let ref_hash = next_hash(start_hash, self.num_hashes, &self.transactions);
if self.hash != ref_hash {
warn!(
"next_hash is invalid expected: {:?} actual: {:?}",
self.hash, ref_hash
);
return false;
}
true
}
pub fn is_tick(&self) -> bool {
self.transactions.is_empty()
}
}
/// Creates the hash `num_hashes` after `start_hash`. If the transaction contains
/// a signature, the final hash will be a hash of both the previous ID and
/// the signature. If num_hashes is zero and there's no transaction data,
/// start_hash is returned.
fn next_hash(start_hash: &Hash, num_hashes: u64, transactions: &[Transaction]) -> Hash {
if num_hashes == 0 && transactions.is_empty() {
return *start_hash;
}
let mut poh = Poh::new(*start_hash, 0);
for _ in 1..num_hashes {
poh.hash();
}
if transactions.is_empty() {
poh.tick().hash
} else {
poh.record(Transaction::hash(transactions)).hash
}
}
pub fn reconstruct_entries_from_blobs<I>(blobs: I) -> Result<(Vec<Entry>, u64)>
where
I: IntoIterator,
I::Item: Borrow<Blob>,
{
let mut entries: Vec<Entry> = vec![];
let mut num_ticks = 0;
for blob in blobs.into_iter() {
let entry: Entry = {
let msg_size = blob.borrow().size();
deserialize(&blob.borrow().data()[..msg_size])?
};
if entry.is_tick() {
num_ticks += 1
}
entries.push(entry)
}
Ok((entries, num_ticks))
}
// an EntrySlice is a slice of Entries
pub trait EntrySlice {
/// Verifies the hashes and counts of a slice of transactions are all consistent.
fn verify(&self, start_hash: &Hash) -> bool;
fn to_shared_blobs(&self) -> Vec<SharedBlob>;
fn to_blobs(&self) -> Vec<Blob>;
fn votes(&self) -> Vec<(Pubkey, Vote, Hash)>;
}
impl EntrySlice for [Entry] {
fn verify(&self, start_hash: &Hash) -> bool {
let genesis = [Entry {
num_hashes: 0,
hash: *start_hash,
transactions: vec![],
}];
let entry_pairs = genesis.par_iter().chain(self).zip(self);
entry_pairs.all(|(x0, x1)| {
let r = x1.verify(&x0.hash);
if !r {
warn!(
"entry invalid!: x0: {:?}, x1: {:?} num txs: {}",
x0.hash,
x1.hash,
x1.transactions.len()
);
}
r
})
}
fn to_blobs(&self) -> Vec<Blob> {
self.iter().map(|entry| entry.to_blob()).collect()
}
fn to_shared_blobs(&self) -> Vec<SharedBlob> {
self.iter().map(|entry| entry.to_shared_blob()).collect()
}
fn votes(&self) -> Vec<(Pubkey, Vote, Hash)> {
self.iter()
.flat_map(|entry| {
entry
.transactions
.iter()
.flat_map(VoteTransaction::get_votes)
})
.collect()
}
}
pub fn next_entry_mut(start: &mut Hash, num_hashes: u64, transactions: Vec<Transaction>) -> Entry {
let entry = Entry::new(&start, num_hashes, transactions);
*start = entry.hash;
entry
}
/// Creates the next entries for given transactions, outputs
/// updates start_hash to hash of last Entry, sets num_hashes to 0
pub fn next_entries_mut(
start_hash: &mut Hash,
num_hashes: &mut u64,
transactions: Vec<Transaction>,
) -> Vec<Entry> {
// TODO: ?? find a number that works better than |?
// V
if transactions.is_empty() || transactions.len() == 1 {
vec![Entry::new_mut(start_hash, num_hashes, transactions)]
} else {
let mut chunk_start = 0;
let mut entries = Vec::new();
while chunk_start < transactions.len() {
let mut chunk_end = transactions.len();
let mut upper = chunk_end;
let mut lower = chunk_start;
let mut next = chunk_end; // be optimistic that all will fit
// binary search for how many transactions will fit in an Entry (i.e. a BLOB)
loop {
debug!(
"chunk_end {}, upper {} lower {} next {} transactions.len() {}",
chunk_end,
upper,
lower,
next,
transactions.len()
);
if Entry::serialized_size(&transactions[chunk_start..chunk_end])
<= BLOB_DATA_SIZE as u64
{
next = (upper + chunk_end) / 2;
lower = chunk_end;
debug!(
"chunk_end {} fits, maybe too well? trying {}",
chunk_end, next
);
} else {
next = (lower + chunk_end) / 2;
upper = chunk_end;
debug!("chunk_end {} doesn't fit! trying {}", chunk_end, next);
}
// same as last time
if next == chunk_end {
debug!("converged on chunk_end {}", chunk_end);
break;
}
chunk_end = next;
}
entries.push(Entry::new_mut(
start_hash,
num_hashes,
transactions[chunk_start..chunk_end].to_vec(),
));
chunk_start = chunk_end;
}
entries
}
}
/// Creates the next Entries for given transactions
pub fn next_entries(
start_hash: &Hash,
num_hashes: u64,
transactions: Vec<Transaction>,
) -> Vec<Entry> {
let mut hash = *start_hash;
let mut num_hashes = num_hashes;
next_entries_mut(&mut hash, &mut num_hashes, transactions)
}
pub fn create_ticks(num_ticks: u64, mut hash: Hash) -> Vec<Entry> {
let mut ticks = Vec::with_capacity(num_ticks as usize);
for _ in 0..num_ticks {
let new_tick = next_entry_mut(&mut hash, 1, vec![]);
ticks.push(new_tick);
}
ticks
}
pub fn make_tiny_test_entries_from_hash(start: &Hash, num: usize) -> Vec<Entry> {
let keypair = Keypair::new();
let mut hash = *start;
let mut num_hashes = 0;
(0..num)
.map(|_| {
Entry::new_mut(
&mut hash,
&mut num_hashes,
vec![BudgetTransaction::new_timestamp(
&keypair,
&keypair.pubkey(),
&keypair.pubkey(),
Utc::now(),
*start,
)],
)
})
.collect()
}
pub fn make_tiny_test_entries(num: usize) -> Vec<Entry> {
let zero = Hash::default();
let one = solana_sdk::hash::hash(&zero.as_ref());
make_tiny_test_entries_from_hash(&one, num)
}
pub fn make_large_test_entries(num_entries: usize) -> Vec<Entry> {
let zero = Hash::default();
let one = solana_sdk::hash::hash(&zero.as_ref());
let keypair = Keypair::new();
let tx = BudgetTransaction::new_timestamp(
&keypair,
&keypair.pubkey(),
&keypair.pubkey(),
Utc::now(),
one,
);
let serialized_size = tx.serialized_size().unwrap();
let num_txs = BLOB_DATA_SIZE / serialized_size as usize;
let txs = vec![tx; num_txs];
let entry = next_entries(&one, 1, txs)[0].clone();
vec![entry; num_entries]
}
#[cfg(test)]
pub fn make_consecutive_blobs(
id: &Pubkey,
num_blobs_to_make: u64,
start_height: u64,
start_hash: Hash,
addr: &std::net::SocketAddr,
) -> Vec<SharedBlob> {
let entries = create_ticks(num_blobs_to_make, start_hash);
let blobs = entries.to_shared_blobs();
let mut index = start_height;
for blob in &blobs {
let mut blob = blob.write().unwrap();
blob.set_index(index);
blob.set_id(id);
blob.forward(true);
blob.meta.set_addr(addr);
index += 1;
}
blobs
}
#[cfg(test)]
/// Creates the next Tick or Transaction Entry `num_hashes` after `start_hash`.
pub fn next_entry(prev_hash: &Hash, num_hashes: u64, transactions: Vec<Transaction>) -> Entry {
assert!(num_hashes > 0 || transactions.is_empty());
Entry {
num_hashes,
hash: next_hash(prev_hash, num_hashes, &transactions),
transactions,
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::entry::Entry;
use crate::packet::{to_blobs, BLOB_DATA_SIZE, PACKET_DATA_SIZE};
use solana_sdk::hash::hash;
use solana_sdk::signature::{Keypair, KeypairUtil};
use solana_sdk::system_transaction::SystemTransaction;
use std::net::{IpAddr, Ipv4Addr, SocketAddr};
#[test]
fn test_entry_verify() {
let zero = Hash::default();
let one = hash(&zero.as_ref());
assert!(Entry::new_tick(0, &zero).verify(&zero)); // base case, never used
assert!(!Entry::new_tick(0, &zero).verify(&one)); // base case, bad
assert!(next_entry(&zero, 1, vec![]).verify(&zero)); // inductive step
assert!(!next_entry(&zero, 1, vec![]).verify(&one)); // inductive step, bad
}
#[test]
fn test_transaction_reorder_attack() {
let zero = Hash::default();
// First, verify entries
let keypair = Keypair::new();
let tx0 = SystemTransaction::new_account(&keypair, &keypair.pubkey(), 0, zero, 0);
let tx1 = SystemTransaction::new_account(&keypair, &keypair.pubkey(), 1, zero, 0);
let mut e0 = Entry::new(&zero, 0, vec![tx0.clone(), tx1.clone()]);
assert!(e0.verify(&zero));
// Next, swap two transactions and ensure verification fails.
e0.transactions[0] = tx1; // <-- attack
e0.transactions[1] = tx0;
assert!(!e0.verify(&zero));
}
#[test]
fn test_witness_reorder_attack() {
let zero = Hash::default();
// First, verify entries
let keypair = Keypair::new();
let tx0 = BudgetTransaction::new_timestamp(
&keypair,
&keypair.pubkey(),
&keypair.pubkey(),
Utc::now(),
zero,
);
let tx1 =
BudgetTransaction::new_signature(&keypair, &keypair.pubkey(), &keypair.pubkey(), zero);
let mut e0 = Entry::new(&zero, 0, vec![tx0.clone(), tx1.clone()]);
assert!(e0.verify(&zero));
// Next, swap two witness transactions and ensure verification fails.
e0.transactions[0] = tx1; // <-- attack
e0.transactions[1] = tx0;
assert!(!e0.verify(&zero));
}
#[test]
fn test_next_entry() {
let zero = Hash::default();
let tick = next_entry(&zero, 1, vec![]);
assert_eq!(tick.num_hashes, 1);
assert_ne!(tick.hash, zero);
let tick = next_entry(&zero, 0, vec![]);
assert_eq!(tick.num_hashes, 0);
assert_eq!(tick.hash, zero);
let keypair = Keypair::new();
let tx0 = BudgetTransaction::new_timestamp(
&keypair,
&keypair.pubkey(),
&keypair.pubkey(),
Utc::now(),
zero,
);
let entry0 = next_entry(&zero, 1, vec![tx0.clone()]);
assert_eq!(entry0.num_hashes, 1);
assert_eq!(entry0.hash, next_hash(&zero, 1, &vec![tx0]));
}
#[test]
#[should_panic]
fn test_next_entry_panic() {
let zero = Hash::default();
let keypair = Keypair::new();
let tx = SystemTransaction::new_account(&keypair, &keypair.pubkey(), 0, zero, 0);
next_entry(&zero, 0, vec![tx]);
}
#[test]
fn test_serialized_size() {
let zero = Hash::default();
let keypair = Keypair::new();
let tx = SystemTransaction::new_account(&keypair, &keypair.pubkey(), 0, zero, 0);
let entry = next_entry(&zero, 1, vec![tx.clone()]);
assert_eq!(
Entry::serialized_size(&[tx]),
serialized_size(&entry).unwrap()
);
}
#[test]
fn test_verify_slice() {
solana_logger::setup();
let zero = Hash::default();
let one = hash(&zero.as_ref());
assert!(vec![][..].verify(&zero)); // base case
assert!(vec![Entry::new_tick(0, &zero)][..].verify(&zero)); // singleton case 1
assert!(!vec![Entry::new_tick(0, &zero)][..].verify(&one)); // singleton case 2, bad
assert!(vec![next_entry(&zero, 0, vec![]); 2][..].verify(&zero)); // inductive step
let mut bad_ticks = vec![next_entry(&zero, 0, vec![]); 2];
bad_ticks[1].hash = one;
assert!(!bad_ticks.verify(&zero)); // inductive step, bad
}
fn make_test_entries() -> Vec<Entry> {
let zero = Hash::default();
let one = hash(&zero.as_ref());
let keypair = Keypair::new();
let vote_account = Keypair::new();
let tx0 = VoteTransaction::new_vote(&vote_account.pubkey(), &vote_account, 1, one, 1);
let tx1 = BudgetTransaction::new_timestamp(
&keypair,
&keypair.pubkey(),
&keypair.pubkey(),
Utc::now(),
one,
);
//
// TODO: this magic number and the mix of transaction types
// is designed to fill up a Blob more or less exactly,
// to get near enough the threshold that
// deserialization falls over if it uses the wrong size()
// parameter to index into blob.data()
//
// magic numbers -----------------+
// |
// V
let mut transactions = vec![tx0; 362];
transactions.extend(vec![tx1; 100]);
next_entries(&zero, 0, transactions)
}
#[test]
fn test_entries_to_shared_blobs() {
solana_logger::setup();
let entries = make_test_entries();
let blob_q = entries.to_blobs();
assert_eq!(reconstruct_entries_from_blobs(blob_q).unwrap().0, entries);
}
#[test]
fn test_bad_blobs_attack() {
solana_logger::setup();
let addr = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(0, 0, 0, 0)), 8000);
let blobs_q = to_blobs(vec![(0, addr)]).unwrap(); // <-- attack!
assert!(reconstruct_entries_from_blobs(blobs_q).is_err());
}
#[test]
fn test_next_entries() {
solana_logger::setup();
let hash = Hash::default();
let next_hash = solana_sdk::hash::hash(&hash.as_ref());
let keypair = Keypair::new();
let vote_account = Keypair::new();
let tx_small =
VoteTransaction::new_vote(&vote_account.pubkey(), &vote_account, 1, next_hash, 2);
let tx_large = BudgetTransaction::new_payment(&keypair, &keypair.pubkey(), 1, next_hash, 0);
let tx_small_size = tx_small.serialized_size().unwrap() as usize;
let tx_large_size = tx_large.serialized_size().unwrap() as usize;
let entry_size = serialized_size(&Entry {
num_hashes: 0,
hash: Hash::default(),
transactions: vec![],
})
.unwrap() as usize;
assert!(tx_small_size < tx_large_size);
assert!(tx_large_size < PACKET_DATA_SIZE);
let threshold = (BLOB_DATA_SIZE - entry_size) / tx_small_size;
// verify no split
let transactions = vec![tx_small.clone(); threshold];
let entries0 = next_entries(&hash, 0, transactions.clone());
assert_eq!(entries0.len(), 1);
assert!(entries0.verify(&hash));
// verify the split with uniform transactions
let transactions = vec![tx_small.clone(); threshold * 2];
let entries0 = next_entries(&hash, 0, transactions.clone());
assert_eq!(entries0.len(), 2);
assert!(entries0.verify(&hash));
// verify the split with small transactions followed by large
// transactions
let mut transactions = vec![tx_small.clone(); BLOB_DATA_SIZE / tx_small_size];
let large_transactions = vec![tx_large.clone(); BLOB_DATA_SIZE / tx_large_size];
transactions.extend(large_transactions);
let entries0 = next_entries(&hash, 0, transactions.clone());
assert!(entries0.len() >= 2);
assert!(entries0.verify(&hash));
}
}