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mod elder_candidates;
mod errors;
mod node_info;
pub mod node_state;
pub mod prefix_map;
pub mod section_authority_provider;
pub mod section_keys;
mod section_peers;
#[cfg(feature = "test-utils")]
pub use self::section_authority_provider::test_utils;
pub use self::section_keys::{SectionKeyShare, SectionKeysProvider};
pub use elder_candidates::ElderCandidates;
pub use node_info::NodeInfo;
pub use node_state::NodeState;
pub use section_authority_provider::{SectionAuthUtils, SectionAuthorityProvider};
use crate::messaging::system::{KeyedSig, SectionAuth, SectionPeers as SectionPeersMsg};
use prefix_map::NetworkPrefixMap;
use crate::types::{log_markers::LogMarker, Peer};
pub use errors::{Error, Result};
use bls::PublicKey as BlsPublicKey;
use section_peers::SectionPeers;
use secured_linked_list::SecuredLinkedList;
use serde::Serialize;
use std::{collections::BTreeSet, convert::TryInto, iter, net::SocketAddr, sync::Arc};
use tokio::sync::RwLock;
use xor_name::{Prefix, XorName};
pub const MIN_ADULT_AGE: u8 = 5;
pub const FIRST_SECTION_MIN_AGE: u8 = MIN_ADULT_AGE + 1;
pub const FIRST_SECTION_MAX_AGE: u8 = 100;
const SN_ELDER_COUNT: &str = "SN_ELDER_COUNT";
pub const DEFAULT_ELDER_COUNT: usize = 7;
pub fn elder_count() -> usize {
match std::env::var(SN_ELDER_COUNT) {
Ok(count) => match count.parse() {
Ok(count) => {
warn!(
"ELDER_COUNT count set from env var SN_ELDER_COUNT: {:?}",
SN_ELDER_COUNT
);
count
}
Err(error) => {
warn!("There was an error parsing {:?} env var. DEFAULT_ELDER_COUNT will be used: {:?}", SN_ELDER_COUNT, error);
DEFAULT_ELDER_COUNT
}
},
Err(_) => DEFAULT_ELDER_COUNT,
}
}
pub fn recommended_section_size() -> usize {
2 * crate::network_knowledge::elder_count()
}
#[inline]
pub const fn supermajority(group_size: usize) -> usize {
1 + group_size * 2 / 3
}
#[derive(Clone, Debug)]
pub struct NetworkKnowledge {
genesis_key: BlsPublicKey,
chain: Arc<RwLock<SecuredLinkedList>>,
signed_sap: Arc<RwLock<SectionAuth<SectionAuthorityProvider>>>,
section_peers: SectionPeers,
prefix_map: NetworkPrefixMap,
all_sections_chains: Arc<RwLock<SecuredLinkedList>>,
}
impl NetworkKnowledge {
pub fn new(
genesis_key: bls::PublicKey,
chain: SecuredLinkedList,
signed_sap: SectionAuth<SectionAuthorityProvider>,
passed_prefix_map: Option<NetworkPrefixMap>,
) -> Result<Self, Error> {
if genesis_key != *chain.root_key() {
return Err(Error::UntrustedProofChain(format!(
"genesis key doesn't match first key in proof chain: {:?}",
chain.root_key()
)));
}
if signed_sap.sig.public_key != *chain.last_key() {
error!("can't create section: SAP signed with incorrect key");
return Err(Error::UntrustedSectionAuthProvider(format!(
"section key doesn't match last key in proof chain: {:?}",
signed_sap.value
)));
}
if !signed_sap.self_verify() {
return Err(Error::UntrustedSectionAuthProvider(format!(
"invalid signature: {:?}",
signed_sap.value
)));
}
if signed_sap.sig.public_key != signed_sap.section_key() {
return Err(Error::UntrustedSectionAuthProvider(format!(
"section key doesn't match signature's key: {:?}",
signed_sap.value
)));
}
if !chain.self_verify() {
return Err(Error::UntrustedProofChain(format!(
"invalid chain: {:?}",
chain
)));
}
let prefix_map = match passed_prefix_map {
Some(prefix_map) => {
if prefix_map.genesis_key() != genesis_key {
return Err(Error::InvalidGenesisKey(prefix_map.genesis_key()));
} else {
prefix_map
}
}
None => NetworkPrefixMap::new(genesis_key),
};
if let Err(err) = prefix_map.update(signed_sap.clone(), &chain) {
debug!("Failed to update NetworkPrefixMap with SAP {:?} and chain {:?} upon creating new NetworkKnowledge intance: {:?}", signed_sap, chain, err);
}
Ok(Self {
genesis_key,
chain: Arc::new(RwLock::new(chain.clone())),
signed_sap: Arc::new(RwLock::new(signed_sap)),
section_peers: SectionPeers::default(),
prefix_map,
all_sections_chains: Arc::new(RwLock::new(chain)),
})
}
pub async fn relocated_to(&self, new_network_nowledge: Self) -> Result<()> {
debug!("Node was relocated to {:?}", new_network_nowledge);
let mut chain = self.chain.write().await;
*chain = new_network_nowledge.section_chain().await;
drop(chain);
let mut signed_sap = self.signed_sap.write().await;
*signed_sap = new_network_nowledge.signed_sap.read().await.clone();
drop(signed_sap);
let _updated = self
.merge_members(new_network_nowledge.section_signed_members().await)
.await?;
Ok(())
}
pub async fn first_node(
peer: Peer,
genesis_sk_set: bls::SecretKeySet,
) -> Result<(NetworkKnowledge, SectionKeyShare)> {
let public_key_set = genesis_sk_set.public_keys();
let secret_key_share = genesis_sk_set.secret_key_share(0);
let genesis_key = public_key_set.public_key();
let section_auth =
create_first_section_authority_provider(&public_key_set, &secret_key_share, peer)?;
let network_knowledge = NetworkKnowledge::new(
genesis_key,
SecuredLinkedList::new(genesis_key),
section_auth,
None,
)?;
for peer in network_knowledge.signed_sap.read().await.elders().cloned() {
let node_state = NodeState::joined(peer, None);
let sig = create_first_sig(&public_key_set, &secret_key_share, &node_state)?;
let _changed = network_knowledge.section_peers.update(SectionAuth {
value: node_state,
sig,
});
}
let section_key_share = SectionKeyShare {
public_key_set,
index: 0,
secret_key_share,
};
Ok((network_knowledge, section_key_share))
}
pub async fn try_update_current_sap(&self, section_key: BlsPublicKey, prefix: &Prefix) -> bool {
match self.prefix_map.get_signed(prefix) {
Some(signed_sap) if signed_sap.value.section_key() == section_key => {
match self
.all_sections_chains
.read()
.await
.get_proof_chain(&self.genesis_key, §ion_key)
{
Ok(section_chain) => {
self.section_peers.retain(prefix);
self.section_peers
.prune_members_archive(§ion_chain)
.await;
let our_prev_prefix = self.prefix().await;
*self.signed_sap.write().await = signed_sap.clone();
*self.chain.write().await = section_chain;
info!(
"Switched our section's SAP ({:?} to {:?}) with new one: {:?}",
our_prev_prefix, prefix, signed_sap
);
true
}
Err(err) => {
trace!(
"We couldn't find section chain for {:?} and section key {:?}: {:?}",
prefix,
section_key,
err
);
false
}
}
}
Some(_) | None => {
trace!(
"We yet don't have the signed SAP for {:?} and section key {:?}",
prefix,
section_key
);
false
}
}
}
pub async fn update_knowledge_if_valid(
&self,
signed_sap: SectionAuth<SectionAuthorityProvider>,
proof_chain: &SecuredLinkedList,
updated_members: Option<SectionPeersMsg>,
our_name: &XorName,
section_keys_provider: &SectionKeysProvider,
) -> Result<bool> {
let mut there_was_an_update = false;
let provided_sap = signed_sap.value.clone();
match self.prefix_map.verify_with_chain_and_update(
signed_sap.clone(),
proof_chain,
&self.section_chain().await,
) {
Ok(true) => {
there_was_an_update = true;
debug!(
"Anti-Entropy: updated network prefix map with SAP for {:?}",
provided_sap.prefix()
);
self.all_sections_chains
.write()
.await
.join(proof_chain.clone())?;
let mut we_have_a_share_of_this_key = false;
let we_are_an_adult = !self.is_elder(our_name).await;
let we_should_become_an_elder = if we_are_an_adult {
provided_sap.contains_elder(our_name)
} else {
true
};
if !we_are_an_adult || we_should_become_an_elder {
we_have_a_share_of_this_key = section_keys_provider
.key_share(&signed_sap.section_key())
.await
.is_ok();
}
trace!(
"we_are_an_adult: {we_are_an_adult},we_have_a_share_of_this_key: {we_have_a_share_of_this_key}"
);
let switch_to_new_sap =
we_have_a_share_of_this_key || (we_are_an_adult && !we_should_become_an_elder);
trace!(
"update_knowledge_if_valid: will switch_to_new_sap {:?}",
switch_to_new_sap
);
if !we_are_an_adult && !we_have_a_share_of_this_key {
error!("We should be an elder, but we're missing the keyshare!");
}
if switch_to_new_sap && provided_sap.prefix().matches(our_name) {
let our_prev_prefix = self.prefix().await;
self.section_peers.retain(&provided_sap.prefix());
info!(
"Updated our section's SAP ({:?} to {:?}) with new one: {:?}",
our_prev_prefix,
provided_sap.prefix(),
provided_sap
);
let section_chain = self
.all_sections_chains
.read()
.await
.get_proof_chain(&self.genesis_key, &provided_sap.section_key())?;
self.section_peers
.prune_members_archive(§ion_chain)
.await;
*self.signed_sap.write().await = signed_sap.clone();
*self.chain.write().await = section_chain;
}
}
Ok(false) => {
debug!(
"Anti-Entropy: discarded SAP for {:?} since it's the same as the one in our records: {:?}",
provided_sap.prefix(), provided_sap
);
}
Err(err) => {
debug!(
"Anti-Entropy: discarded SAP for {:?} since we failed to update prefix map with: {:?}",
provided_sap.prefix(), err
);
}
}
if let Some(members) = updated_members {
let peers = members
.into_iter()
.map(|member| member.into_authed_state())
.collect();
if self.merge_members(peers).await? {
let prefix = self.prefix().await;
info!(
"Updated our section's members ({:?}): {:?}",
prefix, self.section_peers
);
}
}
Ok(there_was_an_update)
}
pub fn prefix_map(&self) -> &NetworkPrefixMap {
&self.prefix_map
}
pub fn section_by_name(&self, name: &XorName) -> Result<SectionAuthorityProvider> {
self.prefix_map.section_by_name(name)
}
pub async fn get_closest_or_opposite_signed_sap(
&self,
name: &XorName,
) -> Option<(SectionAuth<SectionAuthorityProvider>, SecuredLinkedList)> {
let closest_sap = self
.prefix_map
.closest_or_opposite(name, Some(&self.prefix().await));
if let Some(signed_sap) = closest_sap {
if let Ok(proof_chain) = self
.all_sections_chains
.read()
.await
.get_proof_chain(&self.genesis_key, &signed_sap.value.section_key())
{
return Some((signed_sap, proof_chain));
}
}
None
}
pub fn genesis_key(&self) -> &bls::PublicKey {
&self.genesis_key
}
pub async fn merge_members(&self, peers: BTreeSet<SectionAuth<NodeState>>) -> Result<bool> {
let mut there_was_an_update = false;
let chain = self.chain.read().await.clone();
for node_state in peers.iter() {
trace!(
"Updating section members. Name: {:?}, new state: {:?}",
node_state.name(),
node_state.state()
);
if !node_state.verify(&chain) {
error!(
"Can't update section member, name: {:?}, new state: {:?}",
node_state.name(),
node_state.state()
);
} else if self.section_peers.update(node_state.clone()) {
there_was_an_update = true;
}
}
self.section_peers.retain(&self.prefix().await);
Ok(there_was_an_update)
}
pub async fn update_member(&self, node_state: SectionAuth<NodeState>) -> bool {
let node_name = node_state.name();
trace!(
"Updating section member state, name: {:?}, new state: {:?}",
node_name,
node_state.state()
);
if !node_state.verify(&*self.chain.read().await) {
error!(
"Can't update section member, name: {:?}, new state: {:?}",
node_name,
node_state.state()
);
return false;
}
let updated = self.section_peers.update(node_state);
trace!(
"Section member state, name: {:?}, updated: {}",
node_name,
updated
);
updated
}
pub async fn section_chain(&self) -> SecuredLinkedList {
self.chain.read().await.clone()
}
pub async fn get_proof_chain_to_current(
&self,
from_key: &BlsPublicKey,
) -> Result<SecuredLinkedList> {
let our_section_key = self.signed_sap.read().await.section_key();
let proof_chain = self
.chain
.read()
.await
.get_proof_chain(from_key, &our_section_key)?;
Ok(proof_chain)
}
pub async fn section_key(&self) -> bls::PublicKey {
self.signed_sap.read().await.section_key()
}
pub async fn chain_len(&self) -> u64 {
self.chain.read().await.main_branch_len() as u64
}
pub async fn has_chain_key(&self, key: &bls::PublicKey) -> bool {
self.chain.read().await.has_key(key)
}
pub async fn authority_provider(&self) -> SectionAuthorityProvider {
self.signed_sap.read().await.value.clone()
}
pub async fn section_signed_authority_provider(&self) -> SectionAuth<SectionAuthorityProvider> {
self.signed_sap.read().await.clone()
}
pub async fn promote_and_demote_elders(
&self,
our_name: &XorName,
excluded_names: &BTreeSet<XorName>,
) -> Vec<ElderCandidates> {
if let Some((our_elder_candidates, other_elder_candidates)) =
self.try_split(our_name, excluded_names).await
{
return vec![our_elder_candidates, other_elder_candidates];
}
let sap = self.authority_provider().await;
let expected_peers =
self.section_peers
.elder_candidates(elder_count(), &sap, excluded_names, None);
info!(
">>>> ELDER CANDIDATES {}: {:?}",
expected_peers.len(),
expected_peers
);
let expected_names: BTreeSet<_> = expected_peers.iter().map(Peer::name).collect();
let current_names: BTreeSet<_> = sap.names();
if expected_names == current_names {
vec![]
} else if expected_names.len()
< crate::network_knowledge::supermajority(current_names.len())
{
warn!("ignore attempt to reduce the number of elders too much");
vec![]
} else if expected_names.len() < current_names.len() {
warn!("Ignore attempt to shrink the elders");
trace!("current_names {:?}", current_names);
trace!("expected_names {:?}", expected_names);
trace!("excluded_names {:?}", excluded_names);
trace!("section_peers {:?}", self.section_peers);
vec![]
} else {
let elder_candidates = ElderCandidates::new(sap.prefix(), expected_peers);
vec![elder_candidates]
}
}
pub async fn prefix(&self) -> Prefix {
self.signed_sap.read().await.prefix()
}
pub async fn elders(&self) -> Vec<Peer> {
self.authority_provider().await.elders_vec()
}
pub async fn is_elder(&self, name: &XorName) -> bool {
self.signed_sap.read().await.contains_elder(name)
}
pub async fn section_members(&self) -> BTreeSet<NodeState> {
self.section_peers
.members()
.into_iter()
.map(|state| state.value)
.collect()
}
pub async fn section_signed_members(&self) -> BTreeSet<SectionAuth<NodeState>> {
self.section_peers.members()
}
pub async fn section_size(&self) -> usize {
self.section_peers.num_of_members()
}
pub async fn adults(&self) -> Vec<Peer> {
let mut live_adults = vec![];
for node_state in self.section_peers.members() {
if !self.is_elder(&node_state.name()).await {
live_adults.push(*node_state.peer())
}
}
live_adults
}
pub async fn get_section_member(&self, name: &XorName) -> Option<NodeState> {
self.section_peers.get(name)
}
pub async fn is_either_member_or_archived(
&self,
name: &XorName,
) -> Option<SectionAuth<NodeState>> {
self.section_peers.is_either_member_or_archived(name)
}
pub async fn is_section_member(&self, name: &XorName) -> bool {
self.section_peers.is_member(name)
}
pub async fn is_relocated_to_our_section(&self, name: &XorName) -> bool {
self.section_peers.is_relocated_to_our_section(name)
}
pub async fn find_member_by_addr(&self, addr: &SocketAddr) -> Option<Peer> {
self.section_peers
.members()
.into_iter()
.find(|info| info.addr() == *addr)
.map(|info| *info.peer())
}
async fn try_split(
&self,
our_name: &XorName,
excluded_names: &BTreeSet<XorName>,
) -> Option<(ElderCandidates, ElderCandidates)> {
trace!("{}", LogMarker::SplitAttempt);
if self.authority_provider().await.elder_count() < elder_count() {
trace!("No attempt to split as our section does not have enough elders.");
return None;
}
let (prefix_next_bit, our_new_size, sibling_new_size) =
self.get_split_info(our_name, excluded_names).await?;
debug!(
"Upon section split attempt: our section size {:?}, theirs {:?}",
our_new_size, sibling_new_size
);
let sap = self.authority_provider().await;
let our_prefix = self.prefix().await.pushed(prefix_next_bit);
let our_elders = self.section_peers.elder_candidates(
elder_count(),
&sap,
excluded_names,
Some(&our_prefix),
);
let other_prefix = self.prefix().await.pushed(!prefix_next_bit);
let other_elders = self.section_peers.elder_candidates(
elder_count(),
&sap,
excluded_names,
Some(&other_prefix),
);
let our_elder_candidates = ElderCandidates::new(our_prefix, our_elders);
let other_elder_candidates = ElderCandidates::new(other_prefix, other_elders);
Some((our_elder_candidates, other_elder_candidates))
}
pub async fn get_split_info(
&self,
our_name: &XorName,
excluded_names: &BTreeSet<XorName>,
) -> Option<(bool, usize, usize)> {
let (next_bit_index, prefix_next_bit) =
if let Ok(index) = self.prefix().await.bit_count().try_into() {
let prefix_next_bit = our_name.bit(index);
(index, prefix_next_bit)
} else {
warn!("We cannot split as we are at longest prefix possible");
return None;
};
let (our_new_size, sibling_new_size) = self
.section_peers
.members()
.iter()
.filter(|info| !excluded_names.contains(&info.name()))
.map(|info| info.name().bit(next_bit_index) == prefix_next_bit)
.fold((0, 0), |(ours, siblings), is_our_prefix| {
if is_our_prefix {
(ours + 1, siblings)
} else {
(ours, siblings + 1)
}
});
if our_new_size < recommended_section_size()
|| sibling_new_size < recommended_section_size()
{
return None;
}
Some((prefix_next_bit, our_new_size, sibling_new_size))
}
}
fn create_first_section_authority_provider(
pk_set: &bls::PublicKeySet,
sk_share: &bls::SecretKeyShare,
peer: Peer,
) -> Result<SectionAuth<SectionAuthorityProvider>> {
let section_auth =
SectionAuthorityProvider::new(iter::once(peer), Prefix::default(), pk_set.clone());
let sig = create_first_sig(pk_set, sk_share, §ion_auth)?;
Ok(SectionAuth::new(section_auth, sig))
}
fn create_first_sig<T: Serialize>(
pk_set: &bls::PublicKeySet,
sk_share: &bls::SecretKeyShare,
payload: &T,
) -> Result<KeyedSig> {
let bytes = bincode::serialize(payload).map_err(|_| Error::InvalidPayload)?;
let signature_share = sk_share.sign(&bytes);
let signature = pk_set
.combine_signatures(iter::once((0, &signature_share)))
.map_err(|_| Error::InvalidSignatureShare)?;
Ok(KeyedSig {
public_key: pk_set.public_key(),
signature,
})
}
#[cfg(test)]
mod tests {
use super::supermajority;
use proptest::prelude::*;
#[test]
fn supermajority_of_small_group() {
assert_eq!(supermajority(0), 1);
assert_eq!(supermajority(1), 1);
assert_eq!(supermajority(2), 2);
assert_eq!(supermajority(3), 3);
assert_eq!(supermajority(4), 3);
assert_eq!(supermajority(5), 4);
assert_eq!(supermajority(6), 5);
assert_eq!(supermajority(7), 5);
assert_eq!(supermajority(8), 6);
assert_eq!(supermajority(9), 7);
}
proptest! {
#[test]
fn proptest_supermajority(a in 0usize..10000) {
let n = 3 * a;
assert_eq!(supermajority(n), 2 * a + 1);
assert_eq!(supermajority(n + 1), 2 * a + 1);
assert_eq!(supermajority(n + 2), 2 * a + 2);
}
}
}