ban IP addresses if too many banned peers for this IP address (#1543)

## Issue Addressed

#1283 

## Proposed Changes

All peers with the same IP will be considered banned as long as there are more than 5 (constant) peers with this IP that have a score below the ban threshold. As soon as some of those 5 peers get unbanned (through decay) and if there are then less than 5 peers with a score below the threshold the IP will be considered not banned anymore.
This commit is contained in:
blacktemplar 2020-08-21 01:41:12 +00:00
parent ebb25b5569
commit 3f0a113c7f
2 changed files with 341 additions and 43 deletions

View File

@ -7,6 +7,7 @@ use serde::{
ser::{SerializeStructVariant, Serializer},
Serialize,
};
use std::net::IpAddr;
use std::time::Instant;
use types::{EthSpec, SubnetId};
use PeerConnectionStatus::*;
@ -104,6 +105,8 @@ pub enum PeerConnectionStatus {
Banned {
/// moment when the peer was banned.
since: Instant,
/// ip addresses this peer had a the moment of the ban
ip_addresses: Vec<IpAddr>,
},
/// We are currently dialing this peer.
Dialing {
@ -129,7 +132,7 @@ impl Serialize for PeerConnectionStatus {
s.serialize_field("since", &since.elapsed().as_secs())?;
s.end()
}
Banned { since } => {
Banned { since, .. } => {
let mut s = serializer.serialize_struct_variant("", 2, "Banned", 1)?;
s.serialize_field("since", &since.elapsed().as_secs())?;
s.end()
@ -218,15 +221,16 @@ impl PeerConnectionStatus {
}
/// Modifies the status to Banned
pub fn ban(&mut self) {
pub fn ban(&mut self, ip_addresses: Vec<IpAddr>) {
*self = Banned {
since: Instant::now(),
ip_addresses,
};
}
/// The score system has unbanned the peer. Update the connection status
pub fn unban(&mut self) {
if let PeerConnectionStatus::Banned { since } = self {
if let PeerConnectionStatus::Banned { since, .. } = self {
*self = PeerConnectionStatus::Disconnected { since: *since }
}
}

View File

@ -1,11 +1,13 @@
use super::peer_info::{PeerConnectionStatus, PeerInfo};
use super::peer_sync_status::PeerSyncStatus;
use super::score::{Score, ScoreState};
use crate::multiaddr::Protocol;
use crate::rpc::methods::MetaData;
use crate::PeerId;
use rand::seq::SliceRandom;
use slog::{crit, debug, trace, warn};
use std::collections::HashMap;
use std::net::IpAddr;
use std::time::Instant;
use types::{EthSpec, SubnetId};
@ -13,6 +15,9 @@ use types::{EthSpec, SubnetId};
const MAX_DC_PEERS: usize = 500;
/// The maximum number of banned nodes to remember.
const MAX_BANNED_PEERS: usize = 1000;
/// If there are more than `BANNED_PEERS_PER_IP_THRESHOLD` many banned peers with the same IP we ban
/// the IP.
const BANNED_PEERS_PER_IP_THRESHOLD: usize = 5;
/// Storage of known peers, their reputation and information
pub struct PeerDB<TSpec: EthSpec> {
@ -20,18 +25,72 @@ pub struct PeerDB<TSpec: EthSpec> {
peers: HashMap<PeerId, PeerInfo<TSpec>>,
/// The number of disconnected nodes in the database.
disconnected_peers: usize,
/// The number of banned peers in the database.
banned_peers: usize,
/// Counts banned peers in total and per ip
banned_peers_count: BannedPeersCount,
/// PeerDB's logger
log: slog::Logger,
}
pub struct BannedPeersCount {
/// The number of banned peers in the database.
banned_peers: usize,
/// maps ips to number of banned peers with this ip
banned_peers_per_ip: HashMap<IpAddr, usize>,
}
impl BannedPeersCount {
/// Removes the peer from the counts if it is banned. Returns true if the peer was banned and
/// false otherwise.
pub fn remove_banned_peer(&mut self, connection_status: &PeerConnectionStatus) -> bool {
match connection_status {
PeerConnectionStatus::Banned { ip_addresses, .. } => {
self.banned_peers = self.banned_peers.saturating_sub(1);
for address in ip_addresses {
if let Some(count) = self.banned_peers_per_ip.get_mut(address) {
*count = count.saturating_sub(1);
}
}
true
}
_ => false, //if not banned do nothing
}
}
pub fn add_banned_peer(&mut self, connection_status: &PeerConnectionStatus) {
if let PeerConnectionStatus::Banned { ip_addresses, .. } = connection_status {
self.banned_peers += 1;
for address in ip_addresses {
*self.banned_peers_per_ip.entry(*address).or_insert(0) += 1;
}
}
}
pub fn banned_peers(&self) -> usize {
self.banned_peers
}
/// An IP is considered banned if more than BANNED_PEERS_PER_IP_THRESHOLD banned peers
/// exist with this IP
pub fn ip_is_banned(&self, ip: &IpAddr) -> bool {
self.banned_peers_per_ip
.get(ip)
.map_or(false, |count| *count > BANNED_PEERS_PER_IP_THRESHOLD)
}
pub fn new() -> Self {
BannedPeersCount {
banned_peers: 0,
banned_peers_per_ip: HashMap::new(),
}
}
}
impl<TSpec: EthSpec> PeerDB<TSpec> {
pub fn new(log: &slog::Logger) -> Self {
Self {
log: log.clone(),
disconnected_peers: 0,
banned_peers: 0,
banned_peers_count: BannedPeersCount::new(),
peers: HashMap::new(),
}
}
@ -99,17 +158,35 @@ impl<TSpec: EthSpec> PeerDB<TSpec> {
/// Returns true if the Peer is banned.
pub fn is_banned(&self, peer_id: &PeerId) -> bool {
match self.peers.get(peer_id).map(|info| info.score.state()) {
Some(ScoreState::Banned) => true,
_ => false,
if let Some(peer) = self.peers.get(peer_id) {
match peer.score.state() {
ScoreState::Banned => true,
_ => self.ip_is_banned(peer),
}
} else {
false
}
}
fn ip_is_banned(&self, peer: &PeerInfo<TSpec>) -> bool {
peer.listening_addresses.iter().any(|addr| {
addr.iter().any(|p| match p {
Protocol::Ip4(ip) => self.banned_peers_count.ip_is_banned(&ip.into()),
Protocol::Ip6(ip) => self.banned_peers_count.ip_is_banned(&ip.into()),
_ => false,
})
})
}
/// Returns true if the Peer is either banned or in the disconnected state.
pub fn is_banned_or_disconnected(&self, peer_id: &PeerId) -> bool {
match self.peers.get(peer_id).map(|info| info.score.state()) {
Some(ScoreState::Banned) | Some(ScoreState::Disconnected) => true,
_ => false,
if let Some(peer) = self.peers.get(peer_id) {
match peer.score.state() {
ScoreState::Banned | ScoreState::Disconnected => true,
_ => self.ip_is_banned(peer),
}
} else {
false
}
}
@ -233,9 +310,10 @@ impl<TSpec: EthSpec> PeerDB<TSpec> {
if info.connection_status.is_disconnected() {
self.disconnected_peers = self.disconnected_peers.saturating_sub(1);
}
if info.connection_status.is_banned() {
self.banned_peers = self.banned_peers.saturating_sub(1);
}
self.banned_peers_count
.remove_banned_peer(&info.connection_status);
info.connection_status = PeerConnectionStatus::Dialing {
since: Instant::now(),
};
@ -284,9 +362,8 @@ impl<TSpec: EthSpec> PeerDB<TSpec> {
if info.connection_status.is_disconnected() {
self.disconnected_peers = self.disconnected_peers.saturating_sub(1);
}
if info.connection_status.is_banned() {
self.banned_peers = self.banned_peers.saturating_sub(1);
}
self.banned_peers_count
.remove_banned_peer(&info.connection_status);
info.connection_status.connect_ingoing();
}
@ -297,9 +374,8 @@ impl<TSpec: EthSpec> PeerDB<TSpec> {
if info.connection_status.is_disconnected() {
self.disconnected_peers = self.disconnected_peers.saturating_sub(1);
}
if info.connection_status.is_banned() {
self.banned_peers = self.banned_peers.saturating_sub(1);
}
self.banned_peers_count
.remove_banned_peer(&info.connection_status);
info.connection_status.connect_outgoing();
}
@ -329,8 +405,23 @@ impl<TSpec: EthSpec> PeerDB<TSpec> {
self.disconnected_peers = self.disconnected_peers.saturating_sub(1);
}
if !info.connection_status.is_banned() {
info.connection_status.ban();
self.banned_peers += 1;
info.connection_status
.ban(
info.listening_addresses
.iter()
.fold(Vec::new(), |mut v, a| {
for p in a {
match p {
Protocol::Ip4(ip) => v.push(ip.into()),
Protocol::Ip6(ip) => v.push(ip.into()),
_ => (),
}
}
v
}),
);
self.banned_peers_count
.add_banned_peer(&info.connection_status);
}
self.shrink_to_fit();
}
@ -345,8 +436,9 @@ impl<TSpec: EthSpec> PeerDB<TSpec> {
});
if info.connection_status.is_banned() {
self.banned_peers_count
.remove_banned_peer(&info.connection_status);
info.connection_status.unban();
self.banned_peers = self.banned_peers.saturating_sub(1);
}
self.shrink_to_fit();
}
@ -355,9 +447,9 @@ impl<TSpec: EthSpec> PeerDB<TSpec> {
/// Drops the peers with the lowest reputation so that the number of
/// disconnected peers is less than MAX_DC_PEERS
pub fn shrink_to_fit(&mut self) {
// Remove excess baned peers
while self.banned_peers > MAX_BANNED_PEERS {
if let Some(to_drop) = self
// Remove excess banned peers
while self.banned_peers_count.banned_peers() > MAX_BANNED_PEERS {
if let Some(to_drop) = if let Some((id, info)) = self
.peers
.iter()
.filter(|(_, info)| info.connection_status.is_banned())
@ -366,15 +458,23 @@ impl<TSpec: EthSpec> PeerDB<TSpec> {
.score
.partial_cmp(&info_b.score)
.unwrap_or(std::cmp::Ordering::Equal)
})
.map(|(id, _)| id.clone())
{
}) {
self.banned_peers_count
.remove_banned_peer(&info.connection_status);
Some(id.clone())
} else {
// If there is no minimum, this is a coding error.
crit!(
self.log,
"banned_peers > MAX_BANNED_PEERS despite no banned peers in db!"
);
// reset banned_peers this will also exit the loop
self.banned_peers_count = BannedPeersCount::new();
None
} {
debug!(self.log, "Removing old banned peer"; "peer_id" => to_drop.to_string());
self.peers.remove(&to_drop);
}
// If there is no minimum, this is a coding error. For safety we decrease
// the count to avoid a potential infinite loop.
self.banned_peers = self.banned_peers.saturating_sub(1);
}
// Remove excess disconnected peers
@ -422,8 +522,11 @@ impl<TSpec: EthSpec> PeerDB<TSpec> {
#[cfg(test)]
mod tests {
use super::*;
use libp2p::core::Multiaddr;
use slog::{o, Drain};
use std::net::{Ipv4Addr, Ipv6Addr};
use types::MinimalEthSpec;
type M = MinimalEthSpec;
pub fn build_log(level: slog::Level, enabled: bool) -> slog::Logger {
@ -503,13 +606,13 @@ mod tests {
let p = PeerId::random();
pdb.connect_ingoing(&p);
}
assert_eq!(pdb.banned_peers, 0);
assert_eq!(pdb.banned_peers_count.banned_peers(), 0);
for p in pdb.connected_peer_ids().cloned().collect::<Vec<_>>() {
pdb.ban(&p);
}
assert_eq!(pdb.banned_peers, MAX_BANNED_PEERS);
assert_eq!(pdb.banned_peers_count.banned_peers(), MAX_BANNED_PEERS);
}
#[test]
@ -608,24 +711,39 @@ mod tests {
pdb.connect_ingoing(&random_peer2);
pdb.connect_ingoing(&random_peer3);
assert_eq!(pdb.disconnected_peers, pdb.disconnected_peers().count());
assert_eq!(pdb.banned_peers, pdb.banned_peers().count());
assert_eq!(
pdb.banned_peers_count.banned_peers(),
pdb.banned_peers().count()
);
pdb.connect_ingoing(&random_peer);
pdb.disconnect(&random_peer1);
pdb.ban(&random_peer2);
pdb.connect_ingoing(&random_peer3);
assert_eq!(pdb.disconnected_peers, pdb.disconnected_peers().count());
assert_eq!(pdb.banned_peers, pdb.banned_peers().count());
assert_eq!(
pdb.banned_peers_count.banned_peers(),
pdb.banned_peers().count()
);
pdb.ban(&random_peer1);
assert_eq!(pdb.disconnected_peers, pdb.disconnected_peers().count());
assert_eq!(pdb.banned_peers, pdb.banned_peers().count());
assert_eq!(
pdb.banned_peers_count.banned_peers(),
pdb.banned_peers().count()
);
pdb.connect_outgoing(&random_peer2);
assert_eq!(pdb.disconnected_peers, pdb.disconnected_peers().count());
assert_eq!(pdb.banned_peers, pdb.banned_peers().count());
assert_eq!(
pdb.banned_peers_count.banned_peers(),
pdb.banned_peers().count()
);
pdb.ban(&random_peer3);
assert_eq!(pdb.disconnected_peers, pdb.disconnected_peers().count());
assert_eq!(pdb.banned_peers, pdb.banned_peers().count());
assert_eq!(
pdb.banned_peers_count.banned_peers(),
pdb.banned_peers().count()
);
pdb.ban(&random_peer3);
pdb.connect_ingoing(&random_peer1);
@ -633,15 +751,191 @@ mod tests {
pdb.ban(&random_peer3);
pdb.connect_ingoing(&random_peer);
assert_eq!(pdb.disconnected_peers, pdb.disconnected_peers().count());
assert_eq!(pdb.banned_peers, pdb.banned_peers().count());
assert_eq!(
pdb.banned_peers_count.banned_peers(),
pdb.banned_peers().count()
);
pdb.disconnect(&random_peer);
assert_eq!(pdb.disconnected_peers, pdb.disconnected_peers().count());
assert_eq!(pdb.banned_peers, pdb.banned_peers().count());
assert_eq!(
pdb.banned_peers_count.banned_peers(),
pdb.banned_peers().count()
);
pdb.disconnect(&random_peer);
assert_eq!(pdb.disconnected_peers, pdb.disconnected_peers().count());
assert_eq!(pdb.banned_peers, pdb.banned_peers().count());
assert_eq!(
pdb.banned_peers_count.banned_peers(),
pdb.banned_peers().count()
);
pdb.ban(&random_peer);
assert_eq!(pdb.disconnected_peers, pdb.disconnected_peers().count());
}
fn connect_peer_with_ips(pdb: &mut PeerDB<M>, ips: Vec<Vec<IpAddr>>) -> PeerId {
let p = PeerId::random();
pdb.connect_ingoing(&p);
pdb.peers.get_mut(&p).unwrap().listening_addresses = ips
.into_iter()
.map(|ip_addresses| {
let mut addr = Multiaddr::empty();
for ip_address in ip_addresses {
addr.push(Protocol::from(ip_address));
}
addr
})
.collect();
p
}
#[test]
fn test_ban_address() {
let mut pdb = get_db();
let ip1: IpAddr = Ipv4Addr::new(1, 2, 3, 4).into();
let ip2: IpAddr = Ipv6Addr::new(1, 2, 3, 4, 5, 6, 7, 8).into();
let ip3: IpAddr = Ipv4Addr::new(1, 2, 3, 5).into();
let ip4: IpAddr = Ipv6Addr::new(1, 2, 3, 4, 5, 6, 7, 9).into();
let ip5: IpAddr = Ipv4Addr::new(2, 2, 3, 4).into();
let mut peers = Vec::new();
for i in 0..BANNED_PEERS_PER_IP_THRESHOLD + 2 {
peers.push(connect_peer_with_ips(
&mut pdb,
if i == 0 {
vec![vec![ip1], vec![ip2]]
} else {
vec![vec![ip1, ip2], vec![ip3, ip4]]
},
));
}
let p1 = connect_peer_with_ips(&mut pdb, vec![vec![ip1]]);
let p2 = connect_peer_with_ips(&mut pdb, vec![vec![ip2, ip5]]);
let p3 = connect_peer_with_ips(&mut pdb, vec![vec![ip3], vec![ip5]]);
let p4 = connect_peer_with_ips(&mut pdb, vec![vec![ip5, ip4]]);
let p5 = connect_peer_with_ips(&mut pdb, vec![vec![ip5]]);
for p in &peers[..BANNED_PEERS_PER_IP_THRESHOLD + 1] {
pdb.ban(p);
}
//check that ip1 and ip2 are banned but ip3-5 not
assert!(pdb.is_banned(&p1));
assert!(pdb.is_banned(&p2));
assert!(!pdb.is_banned(&p3));
assert!(!pdb.is_banned(&p4));
assert!(!pdb.is_banned(&p5));
//ban also the last peer in peers
pdb.ban(&peers[BANNED_PEERS_PER_IP_THRESHOLD + 1]);
//check that ip1-ip4 are banned but ip5 not
assert!(pdb.is_banned(&p1));
assert!(pdb.is_banned(&p2));
assert!(pdb.is_banned(&p3));
assert!(pdb.is_banned(&p4));
assert!(!pdb.is_banned(&p5));
//peers[0] gets unbanned
pdb.unban(&peers[0]);
//nothing changed
assert!(pdb.is_banned(&p1));
assert!(pdb.is_banned(&p2));
assert!(pdb.is_banned(&p3));
assert!(pdb.is_banned(&p4));
assert!(!pdb.is_banned(&p5));
//peers[1] gets unbanned
pdb.unban(&peers[1]);
//all ips are unbanned
assert!(!pdb.is_banned(&p1));
assert!(!pdb.is_banned(&p2));
assert!(!pdb.is_banned(&p3));
assert!(!pdb.is_banned(&p4));
assert!(!pdb.is_banned(&p5));
}
#[test]
fn test_banned_ip_consistent_after_changing_ips() {
let mut pdb = get_db();
let ip1: IpAddr = Ipv4Addr::new(1, 2, 3, 4).into();
let ip2: IpAddr = Ipv6Addr::new(1, 2, 3, 4, 5, 6, 7, 8).into();
let mut peers = Vec::new();
for _ in 0..BANNED_PEERS_PER_IP_THRESHOLD + 1 {
peers.push(connect_peer_with_ips(&mut pdb, vec![vec![ip1]]));
}
let p1 = connect_peer_with_ips(&mut pdb, vec![vec![ip1]]);
let p2 = connect_peer_with_ips(&mut pdb, vec![vec![ip2]]);
//ban all peers
for p in &peers {
pdb.ban(p);
}
//check ip is banned
assert!(pdb.is_banned(&p1));
assert!(!pdb.is_banned(&p2));
//change addresses of banned peers
for p in &peers {
pdb.peers.get_mut(p).unwrap().listening_addresses =
vec![Multiaddr::empty().with(Protocol::from(ip2))];
}
//check still the same ip is banned
assert!(pdb.is_banned(&p1));
assert!(!pdb.is_banned(&p2));
//unban a peer
pdb.unban(&peers[0]);
//check not banned anymore
assert!(!pdb.is_banned(&p1));
assert!(!pdb.is_banned(&p2));
//check still not banned after new ban
pdb.ban(&peers[0]);
assert!(!pdb.is_banned(&p1));
assert!(!pdb.is_banned(&p2));
//unban and reban all peers
for p in &peers {
pdb.unban(p);
pdb.ban(p);
}
//ip2 is now banned
assert!(!pdb.is_banned(&p1));
assert!(pdb.is_banned(&p2));
//change ips back again
for p in &peers {
pdb.peers.get_mut(p).unwrap().listening_addresses =
vec![Multiaddr::empty().with(Protocol::from(ip1))];
}
//reban every peer except one
for p in &peers[1..] {
pdb.unban(p);
pdb.ban(p);
}
//nothing is banned
assert!(!pdb.is_banned(&p1));
assert!(!pdb.is_banned(&p2));
//reban last peer
pdb.unban(&peers[0]);
pdb.ban(&peers[0]);
//ip1 is banned
assert!(pdb.is_banned(&p1));
assert!(!pdb.is_banned(&p2));
}
}