p2p: max peers per ip

Dockerfile

@@ -16,7 +16,7 @@ ADD . /go-ethereum
 RUN cd /go-ethereum && go run build/ci.go install ./cmd/geth
 
 # Pull Geth into a second stage deploy alpine container
-FROM alpine:3.16.0
+FROM alpine:3.17
 
 ARG BSC_USER=bsc
 ARG BSC_USER_UID=1000
@@ -26,9 +26,9 @@ ENV BSC_HOME=/bsc
 ENV HOME=${BSC_HOME}
 ENV DATA_DIR=/data
 
-ENV PACKAGES ca-certificates~=20220614-r0 jq~=1.6 \
-  bash~=5.1.16-r2 bind-tools~=9.16.37 tini~=0.19.0 \
-  grep~=3.7 curl~=7.83.1 sed~=4.8-r0
+ENV PACKAGES ca-certificates jq \
+  bash bind-tools tini \
+  grep curl sed
 
 RUN apk add --no-cache $PACKAGES \
   && rm -rf /var/cache/apk/* \

eth/handler.go

@@ -20,6 +20,7 @@ import (
 	"errors"
 	"math"
 	"math/big"
+	"strings"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -114,10 +115,12 @@ type handler struct {
 	checkpointNumber uint64      // Block number for the sync progress validator to cross reference
 	checkpointHash   common.Hash // Block hash for the sync progress validator to cross reference
 
-	database ethdb.Database
-	txpool   txPool
-	chain    *core.BlockChain
-	maxPeers int
+	database      ethdb.Database
+	txpool        txPool
+	chain         *core.BlockChain
+	maxPeers      int
+	maxPeersPerIp int
+	peersPerIp    map[string]int
 
 	downloader   *downloader.Downloader
 	blockFetcher *fetcher.BlockFetcher
@@ -161,6 +164,7 @@ func newHandler(config *handlerConfig) (*handler, error) {
 		chain:                  config.Chain,
 		peers:                  config.PeerSet,
 		merger:                 config.Merger,
+		peersPerIp:             make(map[string]int),
 		whitelist:              config.Whitelist,
 		directBroadcast:        config.DirectBroadcast,
 		diffSync:               config.DiffSync,
@@ -362,7 +366,22 @@ func (h *handler) runEthPeer(peer *eth.Peer, handler eth.Handler) error {
 			return p2p.DiscTooManyPeers
 		}
 	}
-	peer.Log().Debug("Ethereum peer connected", "name", peer.Name())
+
+	remoteAddr := peer.Peer.Info().Network.RemoteAddress
+	index := strings.Index(remoteAddr, ":")
+	remoteIp := remoteAddr[:index]
+	if num, ok := h.peersPerIp[remoteIp]; ok && num > h.maxPeersPerIp {
+		peer.Log().Debug("The IP has too many peers", "ip", remoteIp,
+			"maxPeersPerIp", h.maxPeersPerIp,
+			"name", peer.Peer.Info().Name,
+			"Enode", peer.Peer.Info().Enode)
+		return p2p.DiscTooManyPeers
+	}
+	h.peersPerIp[remoteIp] = h.peersPerIp[remoteIp] + 1
+
+	peer.Log().Debug("Ethereum peer connected", "name", peer.Name(),
+		"remoteAddr", remoteAddr, "remoteIp", remoteIp,
+		"number", h.peersPerIp[remoteIp])
 
 	// Register the peer locally
 	if err := h.peers.registerPeer(peer, snap, diff, trust); err != nil {
@@ -578,11 +597,21 @@ func (h *handler) unregisterPeer(id string) {
 	if err := h.peers.unregisterPeer(id); err != nil {
 		logger.Error("Ethereum peer removal failed", "err", err)
 	}
+
+	remoteIp := peer.Peer.Info().Network.RemoteAddress
+	h.peersPerIp[remoteIp] = h.peersPerIp[remoteIp] - 1
+	logger.Debug("unregisterPeer", "ip", remoteIp,
+		"maxPeersPerIp", h.maxPeersPerIp,
+		"name", peer.Peer.Info().Name,
+		"Enode", peer.Peer.Info().Enode)
+	if h.peersPerIp[remoteIp] == 0 {
+		delete(h.peersPerIp, remoteIp)
+	}
 }
 
 func (h *handler) Start(maxPeers int) {
 	h.maxPeers = maxPeers
-
+	h.maxPeersPerIp = 1
 	// broadcast transactions
 	h.wg.Add(1)
 	h.txsCh = make(chan core.NewTxsEvent, txChanSize)

p2p/server.go

@@ -79,6 +79,8 @@ type Config struct {
 	// connected. It must be greater than zero.
 	MaxPeers int
 
+	MaxPeersPerIp int
+
 	// MaxPendingPeers is the maximum number of peers that can be pending in the
 	// handshake phase, counted separately for inbound and outbound connections.
 	// Zero defaults to preset values.