cmd/bootnode, eth, p2p, p2p/discover: clean up the seeder and mesh into eth.

9 files changed, 168 insertions, 144 deletions

diff --git a/cmd/bootnode/main.go b/cmd/bootnode/main.go
index 26912525d..826604cdc 100644
--- a/cmd/bootnode/main.go
+++ b/cmd/bootnode/main.go
@@ -71,7 +71,7 @@ func main() {
 		}
 	}
 
-	if _, err := discover.ListenUDP(nodeKey, *listenAddr, natm, ""); err != nil {
+	if _, err := discover.ListenUDP(nodeKey, *listenAddr, natm, nil); err != nil {
 		log.Fatal(err)
 	}
 	select {}
diff --git a/eth/backend.go b/eth/backend.go
index 382cfc832..039f730f1 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -125,6 +125,8 @@ type Ethereum struct {
 	blockDb common.Database // Block chain database
 	stateDb common.Database // State changes database
 	extraDb common.Database // Extra database (txs, etc)
+	seedDb  *discover.Cache // Peer database seeding the bootstrap
+
 	// Closed when databases are flushed and closed
 	databasesClosed chan bool
 
@@ -179,7 +181,10 @@ func New(config *Config) (*Ethereum, error) {
 	if err != nil {
 		return nil, err
 	}
-	seedDbPath := path.Join(config.DataDir, "seeds")
+	seedDb, err := discover.NewPersistentCache(path.Join(config.DataDir, "seeds"))
+	if err != nil {
+		return nil, err
+	}
 
 	// Perform database sanity checks
 	d, _ := blockDb.Get([]byte("ProtocolVersion"))
@@ -207,6 +212,7 @@ func New(config *Config) (*Ethereum, error) {
 		blockDb:         blockDb,
 		stateDb:         stateDb,
 		extraDb:         extraDb,
+		seedDb:          seedDb,
 		eventMux:        &event.TypeMux{},
 		accountManager:  config.AccountManager,
 		DataDir:         config.DataDir,
@@ -244,7 +250,7 @@ func New(config *Config) (*Ethereum, error) {
 		NAT:            config.NAT,
 		NoDial:         !config.Dial,
 		BootstrapNodes: config.parseBootNodes(),
-		SeedCache:      seedDbPath,
+		SeedCache:      seedDb,
 	}
 	if len(config.Port) > 0 {
 		eth.net.ListenAddr = ":" + config.Port
@@ -423,6 +429,7 @@ done:
 		}
 	}
 
+	s.seedDb.Close()
 	s.blockDb.Close()
 	s.stateDb.Close()
 	s.extraDb.Close()
@@ -450,7 +457,7 @@ func (self *Ethereum) SuggestPeer(nodeURL string) error {
 }
 
 func (s *Ethereum) Stop() {
-	s.txSub.Unsubscribe()         // quits txBroadcastLoop
+	s.txSub.Unsubscribe() // quits txBroadcastLoop
 
 	s.protocolManager.Stop()
 	s.txPool.Stop()
diff --git a/p2p/discover/cache.go b/p2p/discover/cache.go
new file mode 100644
index 000000000..f6bab4591
--- /dev/null
+++ b/p2p/discover/cache.go
@@ -0,0 +1,134 @@
+// Contains the discovery cache, storing previously seen nodes to act as seed
+// servers during bootstrapping the network.
+
+package discover
+
+import (
+	"bytes"
+	"encoding/binary"
+	"net"
+	"os"
+
+	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/syndtr/goleveldb/leveldb"
+	"github.com/syndtr/goleveldb/leveldb/storage"
+)
+
+// Cache stores all nodes we know about.
+type Cache struct {
+	db *leveldb.DB
+}
+
+// Cache version to allow dumping old data if it changes.
+var cacheVersionKey = []byte("pv")
+
+// NewMemoryCache creates a new in-memory peer cache without a persistent backend.
+func NewMemoryCache() (*Cache, error) {
+	db, err := leveldb.Open(storage.NewMemStorage(), nil)
+	if err != nil {
+		return nil, err
+	}
+	return &Cache{db: db}, nil
+}
+
+// NewPersistentCache creates/opens a leveldb backed persistent peer cache, also
+// flushing its contents in case of a version mismatch.
+func NewPersistentCache(path string) (*Cache, error) {
+	// Try to open the cache, recovering any corruption
+	db, err := leveldb.OpenFile(path, nil)
+	if _, iscorrupted := err.(leveldb.ErrCorrupted); iscorrupted {
+		db, err = leveldb.RecoverFile(path, nil)
+	}
+	if err != nil {
+		return nil, err
+	}
+	// The nodes contained in the cache correspond to a certain protocol version.
+	// Flush all nodes if the version doesn't match.
+	currentVer := make([]byte, binary.MaxVarintLen64)
+	currentVer = currentVer[:binary.PutVarint(currentVer, Version)]
+
+	blob, err := db.Get(cacheVersionKey, nil)
+	switch err {
+	case leveldb.ErrNotFound:
+		// Version not found (i.e. empty cache), insert it
+		err = db.Put(cacheVersionKey, currentVer, nil)
+
+	case nil:
+		// Version present, flush if different
+		if !bytes.Equal(blob, currentVer) {
+			db.Close()
+			if err = os.RemoveAll(path); err != nil {
+				return nil, err
+			}
+			return NewPersistentCache(path)
+		}
+	}
+	// Clean up in case of an error
+	if err != nil {
+		db.Close()
+		return nil, err
+	}
+	return &Cache{db: db}, nil
+}
+
+// get retrieves a node with a given id from the seed da
+func (c *Cache) get(id NodeID) *Node {
+	blob, err := c.db.Get(id[:], nil)
+	if err != nil {
+		return nil
+	}
+	node := new(Node)
+	if err := rlp.DecodeBytes(blob, node); err != nil {
+		return nil
+	}
+	return node
+}
+
+// list retrieves a batch of nodes from the database.
+func (c *Cache) list(n int) []*Node {
+	it := c.db.NewIterator(nil, nil)
+	defer it.Release()
+
+	nodes := make([]*Node, 0, n)
+	for i := 0; i < n && it.Next(); i++ {
+		var id NodeID
+		copy(id[:], it.Key())
+
+		if node := c.get(id); node != nil {
+			nodes = append(nodes, node)
+		}
+	}
+	return nodes
+}
+
+// update inserts - potentially overwriting - a node in the seed database.
+func (c *Cache) update(node *Node) error {
+	blob, err := rlp.EncodeToBytes(node)
+	if err != nil {
+		return err
+	}
+	return c.db.Put(node.ID[:], blob, nil)
+}
+
+// add inserts a new node into the seed database.
+func (c *Cache) add(id NodeID, addr *net.UDPAddr, tcpPort uint16) *Node {
+	node := &Node{
+		ID:       id,
+		IP:       addr.IP,
+		DiscPort: addr.Port,
+		TCPPort:  int(tcpPort),
+	}
+	c.update(node)
+
+	return node
+}
+
+// delete removes a node from the database.
+func (c *Cache) delete(id NodeID) error {
+	return c.db.Delete(id[:], nil)
+}
+
+// Close flushes and closes the database files.
+func (c *Cache) Close() {
+	c.db.Close()
+}
diff --git a/p2p/discover/node.go b/p2p/discover/node.go
index 0ec9630d3..e66ca37a4 100644
--- a/p2p/discover/node.go
+++ b/p2p/discover/node.go
@@ -1,10 +1,8 @@
 package discover
 
 import (
-	"bytes"
 	"crypto/ecdsa"
 	"crypto/elliptic"
-	"encoding/binary"
 	"encoding/hex"
 	"errors"
 	"fmt"
@@ -13,16 +11,12 @@ import (
 	"math/rand"
 	"net"
 	"net/url"
-	"os"
 	"strconv"
 	"strings"
 
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/crypto/secp256k1"
 	"github.com/ethereum/go-ethereum/rlp"
-	"github.com/syndtr/goleveldb/leveldb"
-	"github.com/syndtr/goleveldb/leveldb/opt"
-	"github.com/syndtr/goleveldb/leveldb/storage"
 )
 
 const nodeIDBits = 512
@@ -310,111 +304,3 @@ func randomID(a NodeID, n int) (b NodeID) {
 	}
 	return b
 }
-
-// nodeDB stores all nodes we know about.
-type nodeDB struct {
-	ldb *leveldb.DB
-}
-
-var dbVersionKey = []byte("pv")
-
-// Opens the backing LevelDB. If path is "", we use an in-memory database.
-func newNodeDB(path string, version int64) (db *nodeDB, err error) {
-	db = new(nodeDB)
-	opts := new(opt.Options)
-	if path == "" {
-		db.ldb, err = leveldb.Open(storage.NewMemStorage(), opts)
-	} else {
-		db.ldb, err = openNodeDB(path, opts, version)
-	}
-	return db, err
-}
-
-// openNodeDB opens a persistent seed cache, flushing old versions.
-func openNodeDB(path string, opts *opt.Options, version int64) (*leveldb.DB, error) {
-	ldb, err := leveldb.OpenFile(path, opts)
-	if _, iscorrupted := err.(leveldb.ErrCorrupted); iscorrupted {
-		ldb, err = leveldb.RecoverFile(path, opts)
-	}
-	if err != nil {
-		return nil, err
-	}
-	// The nodes contained in the database correspond to a certain
-	// protocol version. Flush all nodes if the DB version doesn't match.
-	// There is no need to do this for memory databases because they
-	// won't ever be used with a different protocol version.
-	shouldVal := make([]byte, binary.MaxVarintLen64)
-	shouldVal = shouldVal[:binary.PutVarint(shouldVal, version)]
-	val, err := ldb.Get(dbVersionKey, nil)
-	if err == leveldb.ErrNotFound {
-		err = ldb.Put(dbVersionKey, shouldVal, nil)
-	} else if err == nil && !bytes.Equal(val, shouldVal) {
-		// Delete and start over.
-		ldb.Close()
-		if err = os.RemoveAll(path); err != nil {
-			return nil, err
-		}
-		return openNodeDB(path, opts, version)
-	}
-	if err != nil {
-		ldb.Close()
-		ldb = nil
-	}
-	return ldb, err
-}
-
-// get retrieves a node with a given id from the seed da
-func (db *nodeDB) get(id NodeID) *Node {
-	v, err := db.ldb.Get(id[:], nil)
-	if err != nil {
-		return nil
-	}
-	n := new(Node)
-	if err := rlp.DecodeBytes(v, n); err != nil {
-		return nil
-	}
-	return n
-}
-
-// list retrieves a batch of nodes from the database.
-func (db *nodeDB) list(n int) []*Node {
-	it := db.ldb.NewIterator(nil, nil)
-	defer it.Release()
-
-	nodes := make([]*Node, 0, n)
-	for i := 0; i < n && it.Next(); i++ {
-		var id NodeID
-		copy(id[:], it.Key())
-
-		if node := db.get(id); node != nil {
-			nodes = append(nodes, node)
-		}
-	}
-	return nodes
-}
-
-// update inserts - potentially overwriting - a node in the seed database.
-func (db *nodeDB) update(n *Node) error {
-	v, err := rlp.EncodeToBytes(n)
-	if err != nil {
-		return err
-	}
-	return db.ldb.Put(n.ID[:], v, nil)
-}
-
-// add inserts a new node into the seed database.
-func (db *nodeDB) add(id NodeID, addr *net.UDPAddr, tcpPort uint16) *Node {
-	n := &Node{ID: id, IP: addr.IP, DiscPort: addr.Port, TCPPort: int(tcpPort)}
-	db.update(n)
-	return n
-}
-
-// delete removes a node from the database.
-func (db *nodeDB) delete(id NodeID) error {
-	return db.ldb.Delete(id[:], nil)
-}
-
-// close flushes and closes the database files.
-func (db *nodeDB) close() {
-	db.ldb.Close()
-}
diff --git a/p2p/discover/table.go b/p2p/discover/table.go
index fa791c9f3..98371d6f9 100644
--- a/p2p/discover/table.go
+++ b/p2p/discover/table.go
@@ -27,6 +27,7 @@ type Table struct {
 	mutex   sync.Mutex        // protects buckets, their content, and nursery
 	buckets [nBuckets]*bucket // index of known nodes by distance
 	nursery []*Node           // bootstrap nodes
+	cache   *Cache            // cache of known nodes
 
 	bondmu    sync.Mutex
 	bonding   map[NodeID]*bondproc
@@ -34,7 +35,6 @@ type Table struct {
 
 	net  transport
 	self *Node // metadata of the local node
-	db   *nodeDB
 }
 
 type bondproc struct {
@@ -61,17 +61,15 @@ type bucket struct {
 	entries    []*Node
 }
 
-func newTable(t transport, ourID NodeID, ourAddr *net.UDPAddr, seedCache string) *Table {
-	// Load the bootstrap seed cache (use in memory db upon failure)
-	db, err := newNodeDB(seedCache, Version)
-	if err != nil {
-		glog.V(logger.Warn).Infoln("Failed to open bootstrap seed cache:", err)
-		db, _ = newNodeDB("", Version)
+func newTable(t transport, ourID NodeID, ourAddr *net.UDPAddr, seeder *Cache) *Table {
+	// If no seed cache was given, use an in-memory one
+	if seeder == nil {
+		seeder, _ = NewMemoryCache()
 	}
 	// Create the bootstrap table
 	tab := &Table{
 		net:       t,
-		db:        db,
+		cache:     seeder,
 		self:      newNode(ourID, ourAddr),
 		bonding:   make(map[NodeID]*bondproc),
 		bondslots: make(chan struct{}, maxBondingPingPongs),
@@ -93,7 +91,6 @@ func (tab *Table) Self() *Node {
 // Close terminates the network listener and flushes the seed cache.
 func (tab *Table) Close() {
 	tab.net.close()
-	tab.db.close()
 }
 
 // Bootstrap sets the bootstrap nodes. These nodes are used to connect
@@ -178,10 +175,10 @@ func (tab *Table) refresh() {
 	result := tab.Lookup(randomID(tab.self.ID, ld))
 	if len(result) == 0 {
 		// Pick a batch of previously know seeds to lookup with and discard them (will come back if they are still live)
-		seeds := tab.db.list(10)
+		seeds := tab.cache.list(10)
 		for _, seed := range seeds {
 			glog.V(logger.Debug).Infoln("Seeding network with:", seed)
-			tab.db.delete(seed.ID)
+			tab.cache.delete(seed.ID)
 		}
 		// Bootstrap the table with a self lookup
 		all := tab.bondall(append(tab.nursery, seeds...))
@@ -252,7 +249,7 @@ func (tab *Table) bondall(nodes []*Node) (result []*Node) {
 // of the process can be skipped.
 func (tab *Table) bond(pinged bool, id NodeID, addr *net.UDPAddr, tcpPort uint16) (*Node, error) {
 	var n *Node
-	if n = tab.db.get(id); n == nil {
+	if n = tab.cache.get(id); n == nil {
 		tab.bondmu.Lock()
 		w := tab.bonding[id]
 		if w != nil {
@@ -297,7 +294,7 @@ func (tab *Table) pingpong(w *bondproc, pinged bool, id NodeID, addr *net.UDPAdd
 		// waitping will simply time out.
 		tab.net.waitping(id)
 	}
-	w.n = tab.db.add(id, addr, tcpPort)
+	w.n = tab.cache.add(id, addr, tcpPort)
 	close(w.done)
 }
 
diff --git a/p2p/discover/table_test.go b/p2p/discover/table_test.go
index e2bd3c8ad..8274731e3 100644
--- a/p2p/discover/table_test.go
+++ b/p2p/discover/table_test.go
@@ -15,7 +15,7 @@ import (
 func TestTable_pingReplace(t *testing.T) {
 	doit := func(newNodeIsResponding, lastInBucketIsResponding bool) {
 		transport := newPingRecorder()
-		tab := newTable(transport, NodeID{}, &net.UDPAddr{}, "")
+		tab := newTable(transport, NodeID{}, &net.UDPAddr{}, nil)
 		last := fillBucket(tab, 200)
 		pingSender := randomID(tab.self.ID, 200)
 
@@ -145,7 +145,7 @@ func TestTable_closest(t *testing.T) {
 
 	test := func(test *closeTest) bool {
 		// for any node table, Target and N
-		tab := newTable(nil, test.Self, &net.UDPAddr{}, "")
+		tab := newTable(nil, test.Self, &net.UDPAddr{}, nil)
 		tab.add(test.All)
 
 		// check that doClosest(Target, N) returns nodes
@@ -217,7 +217,7 @@ func TestTable_Lookup(t *testing.T) {
 	self := gen(NodeID{}, quickrand).(NodeID)
 	target := randomID(self, 200)
 	transport := findnodeOracle{t, target}
-	tab := newTable(transport, self, &net.UDPAddr{}, "")
+	tab := newTable(transport, self, &net.UDPAddr{}, nil)
 
 	// lookup on empty table returns no nodes
 	if results := tab.Lookup(target); len(results) > 0 {
diff --git a/p2p/discover/udp.go b/p2p/discover/udp.go
index c26703f19..6805fb686 100644
--- a/p2p/discover/udp.go
+++ b/p2p/discover/udp.go
@@ -144,7 +144,7 @@ type reply struct {
 }
 
 // ListenUDP returns a new table that listens for UDP packets on laddr.
-func ListenUDP(priv *ecdsa.PrivateKey, laddr string, natm nat.Interface, seedCache string) (*Table, error) {
+func ListenUDP(priv *ecdsa.PrivateKey, laddr string, natm nat.Interface, seeder *Cache) (*Table, error) {
 	addr, err := net.ResolveUDPAddr("udp", laddr)
 	if err != nil {
 		return nil, err
@@ -153,12 +153,12 @@ func ListenUDP(priv *ecdsa.PrivateKey, laddr string, natm nat.Interface, seedCac
 	if err != nil {
 		return nil, err
 	}
-	tab, _ := newUDP(priv, conn, natm, seedCache)
+	tab, _ := newUDP(priv, conn, natm, seeder)
 	glog.V(logger.Info).Infoln("Listening,", tab.self)
 	return tab, nil
 }
 
-func newUDP(priv *ecdsa.PrivateKey, c conn, natm nat.Interface, seedCache string) (*Table, *udp) {
+func newUDP(priv *ecdsa.PrivateKey, c conn, natm nat.Interface, seeder *Cache) (*Table, *udp) {
 	udp := &udp{
 		conn:       c,
 		priv:       priv,
@@ -176,7 +176,7 @@ func newUDP(priv *ecdsa.PrivateKey, c conn, natm nat.Interface, seedCache string
 			realaddr = &net.UDPAddr{IP: ext, Port: realaddr.Port}
 		}
 	}
-	udp.Table = newTable(udp, PubkeyID(&priv.PublicKey), realaddr, seedCache)
+	udp.Table = newTable(udp, PubkeyID(&priv.PublicKey), realaddr, seeder)
 	go udp.loop()
 	go udp.readLoop()
 	return udp.Table, udp
@@ -449,7 +449,7 @@ func (req *findnode) handle(t *udp, from *net.UDPAddr, fromID NodeID, mac []byte
 	if expired(req.Expiration) {
 		return errExpired
 	}
-	if t.db.get(fromID) == nil {
+	if t.cache.get(fromID) == nil {
 		// No bond exists, we don't process the packet. This prevents
 		// an attack vector where the discovery protocol could be used
 		// to amplify traffic in a DDOS attack. A malicious actor
diff --git a/p2p/discover/udp_test.go b/p2p/discover/udp_test.go
index 782895e46..299f94543 100644
--- a/p2p/discover/udp_test.go
+++ b/p2p/discover/udp_test.go
@@ -41,7 +41,7 @@ func newUDPTest(t *testing.T) *udpTest {
 		remotekey:  newkey(),
 		remoteaddr: &net.UDPAddr{IP: net.IP{1, 2, 3, 4}, Port: 30303},
 	}
-	test.table, test.udp = newUDP(test.localkey, test.pipe, nil, "")
+	test.table, test.udp = newUDP(test.localkey, test.pipe, nil, nil)
 	return test
 }
 
@@ -157,7 +157,7 @@ func TestUDP_findnode(t *testing.T) {
 
 	// ensure there's a bond with the test node,
 	// findnode won't be accepted otherwise.
-	test.table.db.add(PubkeyID(&test.remotekey.PublicKey), test.remoteaddr, 99)
+	test.table.cache.add(PubkeyID(&test.remotekey.PublicKey), test.remoteaddr, 99)
 
 	// check that closest neighbors are returned.
 	test.packetIn(nil, findnodePacket, &findnode{Target: testTarget, Expiration: futureExp})
diff --git a/p2p/server.go b/p2p/server.go
index 39b0b8b6e..5f1b80f51 100644
--- a/p2p/server.go
+++ b/p2p/server.go
@@ -59,9 +59,9 @@ type Server struct {
 	// with the rest of the network.
 	BootstrapNodes []*discover.Node
 
-	// SeedCache is the path to the database containing the previously seen live
-	// nodes in the network to use as potential bootstrap seeds.
-	SeedCache string
+	// SeedCache is the database containing the previously seen live nodes in
+	// the network to use as potential bootstrap seeds.
+	SeedCache *discover.Cache
 
 	// Protocols should contain the protocols supported
 	// by the server. Matching protocols are launched for