// threadedHandleConn reads header data from a connection, then routes it to the
// appropriate handler for further processing.
func (g *Gateway) threadedHandleConn(conn modules.PeerConn) {
defer conn.Close()
var id rpcID
if err := encoding.ReadObject(conn, &id, 8); err != nil {
return
}
// call registered handler for this ID
lockid := g.mu.RLock()
fn, ok := g.handlers[id]
g.mu.RUnlock(lockid)
if !ok {
g.log.Printf("WARN: incoming conn %v requested unknown RPC \"%v\"", conn.RemoteAddr(), id)
return
}
// call fn
err := fn(conn)
// don't log benign errors
if err == modules.ErrDuplicateTransactionSet || err == modules.ErrBlockKnown {
err = nil
}
if err != nil {
g.log.Printf("WARN: incoming RPC \"%v\" failed: %v", id, err)
}
}
// requestNodes is the calling end of the ShareNodes RPC.
func (g *Gateway) requestNodes(conn modules.PeerConn) error {
var nodes []modules.NetAddress
if err := encoding.ReadObject(conn, &nodes, maxSharedNodes*maxAddrLength); err != nil {
return err
}
g.log.Printf("INFO: %v sent us %v nodes", conn.RemoteAddr(), len(nodes))
id := g.mu.Lock()
for _, node := range nodes {
g.addNode(node)
}
g.save()
g.mu.Unlock(id)
return nil
}
// shareNodes is the receiving end of the ShareNodes RPC. It writes up to 10
// randomly selected nodes to the caller.
func (g *Gateway) shareNodes(conn modules.PeerConn) error {
conn.SetDeadline(time.Now().Add(connStdDeadline))
// Assemble a list of nodes to send to the peer.
var nodes []modules.NetAddress
func() {
g.mu.RLock()
defer g.mu.RUnlock()
// Create a random permutation of nodes from the gateway to iterate
// through.
gnodes := make([]modules.NetAddress, 0, len(g.nodes))
for node := range g.nodes {
gnodes = append(gnodes, node)
}
perm, err := crypto.Perm(len(g.nodes))
if err != nil {
g.log.Severe("Unable to get random permutation for sharing nodes")
}
// Iterate through the random permutation of nodes and select the
// desirable ones.
remoteNA := modules.NetAddress(conn.RemoteAddr().String())
for _, i := range perm {
// Don't share local peers with remote peers. That means that if 'node'
// is loopback, it will only be shared if the remote peer is also
// loopback. And if 'node' is private, it will only be shared if the
// remote peer is either the loopback or is also private.
node := gnodes[i]
if node.IsLoopback() && !remoteNA.IsLoopback() {
continue
}
if node.IsLocal() && !remoteNA.IsLocal() {
continue
}
nodes = append(nodes, node)
if uint64(len(nodes)) == maxSharedNodes {
break
}
}
}()
return encoding.WriteObject(conn, nodes)
}
// threadedHandleConn reads header data from a connection, then routes it to the
// appropriate handler for further processing.
func (g *Gateway) threadedHandleConn(conn modules.PeerConn) {
defer conn.Close()
var id rpcID
if err := encoding.ReadObject(conn, &id, 8); err != nil {
g.log.Printf("WARN: could not read RPC identifier from incoming conn %v: %v", conn.RemoteAddr(), err)
return
}
// call registered handler for this ID
lockid := g.mu.RLock()
fn, ok := g.handlers[id]
g.mu.RUnlock(lockid)
if !ok {
g.log.Printf("WARN: incoming conn %v requested unknown RPC \"%v\"", conn.RemoteAddr(), id)
return
}
if err := fn(conn); err != nil {
g.log.Printf("WARN: incoming RPC \"%v\" failed: %v", id, err)
}
}
// relayBlock is an RPC that accepts a block from a peer.
func (cs *ConsensusSet) relayBlock(conn modules.PeerConn) error {
// Decode the block from the connection.
var b types.Block
err := encoding.ReadObject(conn, &b, types.BlockSizeLimit)
if err != nil {
return err
}
// Submit the block to the consensus set.
err = cs.AcceptBlock(b)
if err == errOrphan {
// If the block is an orphan, try to find the parents. The block
// received from the peer is discarded and will be downloaded again if
// the parent is found.
go cs.gateway.RPC(modules.NetAddress(conn.RemoteAddr().String()), "SendBlocks", cs.threadedReceiveBlocks)
}
if err != nil {
return err
}
return nil
}