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crate::ix!();
pub trait RelayAddress {
fn relay_address(self: Arc<Self>,
originator: NodeId,
addr: &Address,
reachable: bool);
}
impl RelayAddress for PeerManager {
/**
| Relay (gossip) an address to a few randomly
| chosen nodes.
|
| -----------
| @param[in] originator
|
| The id of the peer that sent us the address.
| We don't want to relay it back.
| ----------
| @param[in] addr
|
| Address to relay.
| ----------
| @param[in] fReachable
|
| Whether the address' network is reachable.
| We relay unreachable addresses less.
|
*/
fn relay_address(
self: Arc<Self>,
originator: NodeId,
addr: &Address,
reachable: bool) {
// We choose the same nodes within a given
// 24h window (if the list of connected
// nodes does not change) and we don't
// relay to nodes that already know an
// address.
//
// So within 24h we will likely relay
// a given address once. This is to
// prevent a peer from unjustly giving
// their address better propagation by
// sending it to us repeatedly.
if !reachable && !addr.is_relayable() {
return;
}
// Relay to a limited number of other
// nodes
//
// Use deterministic randomness to send to
// the same nodes for 24 hours at a time
// so the m_addr_knowns of the chosen
// nodes prevent repeats
let hash_addr: u64 = addr.get_hash();
let mut hasher: SipHasher = self.connman.get()
.get_deterministic_randomizer(RANDOMIZER_ID_ADDRESS_RELAY);
hasher.write_u64(hash_addr << 32);
hasher.write_u64(
(u64::try_from(get_datetime().unix_timestamp()).unwrap() + hash_addr) / (24 * 60 * 60)
);
let mut insecure_rand = FastRandomContext::default();
// We choose the same nodes within a given
// 24h window (if the list of connected
// nodes does not change) and we don't
// relay to nodes that already know an
// address. So within 24h we will likely
// relay a given address once. This is to
// prevent a peer from unjustly giving
// their address better propagation by
// sending it to us repeatedly.
if !reachable && !addr.is_relayable() {
return;
}
// Relay to a limited number of other
// nodes
//
// Use deterministic randomness to send to
// the same nodes for 24 hours at a time
// so the m_addr_knowns of the chosen
// nodes prevent repeats
let hash_addr: u64 = addr.get_hash();
let mut hasher: SipHasher = self.connman.get()
.get_deterministic_randomizer(RANDOMIZER_ID_ADDRESS_RELAY);
hasher.write_u64(hash_addr << 32);
hasher.write_u64(
(u64::try_from(get_datetime().unix_timestamp()).unwrap() + hash_addr) / (24 * 60 * 60)
);
let mut insecure_rand = FastRandomContext::default();
// Relay reachable addresses to
// 2 peers. Unreachable addresses are
// relayed randomly to 1 or 2 peers.
let n_relay_nodes: usize = match reachable || (hasher.finish() & 1) != 0 {
true => 2,
false => 1
};
struct Item {
first: u64,
second: Amo<Peer>,
}
let mut best: Vec<Item> = vec![
Item { first: 0, second: amo_none() },
Item { first: 0, second: amo_none() }
];
assert!(n_relay_nodes <= best.len());
let mut peer_map = self.peer_map.get();
for (id,peer) in peer_map.iter() {
if peer.get().addr_relay_enabled.load(atomic::Ordering::Relaxed)
&& *id != originator
&& peer.get().is_addr_compatible(addr)
{
let mut siphasher = SipHasher::from(hasher.clone());
siphasher.write_i64(*id);
let hash_key: u64 = siphasher.finish();
for i in 0_usize..n_relay_nodes {
if hash_key > best[i].first
{
let src = &best[i..n_relay_nodes - 1];
let rmin = i + 1;
let rmax = n_relay_nodes - 1;
let range =
(i + 1)
..
(i + 1 + src.len());
let other: Vec<Item> = best.drain(rmin..=rmax).collect();
best.splice( range, other );
best[i] = Item { first: hash_key, second: peer.clone() };
break;
}
}
}
}
let mut i: usize = 0;
while i < n_relay_nodes.try_into().unwrap() && best[i].first != 0
{
best[i].second.get_mut().push_address(
addr,
&mut insecure_rand
);
i += 1;
}
}
}