func (rpcs *rpcRex) HandleCall(message *etf.Term, from *etf.Tuple) (reply *etf.Term) {
nLog("REX: HandleCall: %#v, From: %#v", *message, *from)
var replyTerm etf.Term
valid := false
switch req := (*message).(type) {
case etf.Tuple:
if len(req) > 0 {
switch act := req[0].(type) {
case etf.Atom:
if string(act) == "call" {
valid = true
if fun, ok := rpcs.callMap[modFun{string(req[1].(etf.Atom)), string(req[2].(etf.Atom))}]; ok {
replyTerm = fun(req[3].(etf.List))
} else {
replyTerm = etf.Term(etf.Tuple{etf.Atom("badrpc"), etf.Tuple{etf.Atom("EXIT"), etf.Tuple{etf.Atom("undef"), etf.List{etf.Tuple{req[1], req[2], req[3], etf.List{}}}}}})
}
}
}
}
}
if !valid {
replyTerm = etf.Term(etf.Tuple{etf.Atom("badrpc"), etf.Atom("unknown")})
}
reply = &replyTerm
return
}
// shutdown request
// takes no arguments
func (r *Relay) rpcShutdown(terms etf.List) etf.Term {
if len(terms) != 0 {
return etf.Term(etf.Tuple{etf.Atom("error"), etf.Atom("badarith")})
}
r.shutdown()
r.shutdownChan <- struct{}{}
return etf.Term(etf.Atom("ok"))
}
// rpc funcs for erlang nodes
// args must be in form `[Name:string]`
// returns either `ok` or `{error, Reason}`
func (r *Relay) rpcCreateFS(terms etf.List) etf.Term {
if len(terms) != 1 {
return etf.Term(etf.Tuple{etf.Atom("error"), etf.Atom("badarith")})
}
t := terms[0]
if _, ok := t.(string); !ok {
return etf.Term(etf.Tuple{etf.Atom("error"), etf.Atom("badarg")})
}
name := t.(string)
err := r.createFS(name)
if err != nil {
println("cannot create fs: ", err)
return etf.Term(etf.Tuple{etf.Atom("error"), etf.Atom("failed-to-create-fs")})
}
return etf.Term(etf.Atom("ok"))
}
// HandleCall handles incoming messages from `gen_server:call/2`, if returns non-nil term,
// then calling process have reply
// Call `gen_server:call({go_srv, gonode@localhost}, Message)` at Erlang node
func (gs *gonodeSrv) HandleCall(message *etf.Term, from *etf.Tuple) (reply *etf.Term) {
log.Printf("GO_SRV: HandleCall: %#v, From: %#v", *message, *from)
// Just create new term tuple where first element is atom 'ok', second 'go_reply' and third is original message
replyTerm := etf.Term(etf.Tuple{etf.Atom("ok"), etf.Atom("go_reply"), *message})
reply = &replyTerm
return
}
// args must be in form `[FSName:string, DevName:string, isSensor/optional,
// isAffector/optional]
// return `{ok, Pid}` or `{error, Reason}`
func (r *Relay) rpcCreateDevice(terms etf.List) etf.Term {
if len(terms) != 3 {
return etf.Term(etf.Tuple{etf.Atom("error"), etf.Atom("badarith")})
}
tFSName := terms[0]
if _, ok := tFSName.(string); !ok {
return etf.Term(etf.Tuple{etf.Atom("error"), etf.Atom("badarg")})
}
fsName := tFSName.(string)
tDeviceName := terms[1]
if _, ok := tDeviceName.(string); !ok {
return etf.Term(etf.Tuple{etf.Atom("error"), etf.Atom("badarg")})
}
deviceName := tDeviceName.(string)
if _, ok := terms[2].(etf.List); !ok {
return etf.Term(etf.Tuple{etf.Atom("error"), etf.Atom("badarg")})
}
isSensor, isAffector, err := parseCreateFlags(terms[2].(etf.List))
if err != nil {
return etf.Term(etf.Tuple{etf.Atom("error"), etf.Atom("badarg")})
}
fullName, err := r.createDevice(fsName, deviceName, isSensor, isAffector)
if err != nil {
println("failed to create device: ", err)
return etf.Term(etf.Tuple{etf.Atom("error"), etf.Atom("failed-to-create-device")})
}
return etf.Term(etf.Tuple{etf.Atom("ok"), fullName})
}
// affecter data request
// msg must be atom `req`
func (d *deviceProc) HandleCall(msg *etf.Term, from *etf.Tuple) *etf.Term {
println("handling call")
if atom, ok := (*msg).(etf.Atom); !ok {
t := etf.Term(etf.Tuple{etf.Atom("error"), etf.Atom("badarg")})
return &t
} else {
if string(atom) != "req" {
t := etf.Term(etf.Tuple{etf.Atom("error"), etf.Atom("badarg")})
return &t
}
buf := d.device.Affect()
if buf == nil {
t := etf.Term(etf.Tuple{etf.Atom("ok"), etf.Atom("nil")})
return &t
} else {
t := etf.Term(etf.Tuple{etf.Atom("ok"), buf})
return &t
}
}
}
func (rpcs *rpcRex) HandleCall(message *etf.Term, from *etf.Tuple) (reply *etf.Term) {
nLog("REX: HandleCall: %#v, From: %#v", *message, *from)
switch req := (*message).(type) {
case etf.Tuple:
if len(req) > 0 {
switch act := req[0].(type) {
case etf.Atom:
if string(act) == "call" {
nLog("RPC CALL: Module: %#v, Function: %#v, Args: %#v, GroupLeader: %#v", req[1], req[2], req[3], req[4])
replyTerm := etf.Term(etf.Tuple{req[1], req[2]})
reply = &replyTerm
}
}
}
}
if reply == nil {
replyTerm := etf.Term(etf.Tuple{etf.Atom("badrpc"), etf.Atom("unknown")})
reply = &replyTerm
}
return
}
func main() {
// Parse CLI flags
flag.Parse()
setup_logging()
write_pid()
log.Println("node started")
// Initialize new node with given name and cookie
enode := node.NewNode(NodeName, Cookie)
// Allow node be available on EpmdPort port
err = enode.Publish(EpmdPort)
if err != nil {
log.Fatalf("Cannot publish: %s", err)
}
// Create channel to receive message when main process should be stopped
completeChan := make(chan bool)
// Initialize new instance of srv structure which implements Process behaviour
eSrv := new(srv)
// Spawn process with one arguments
enode.Spawn(eSrv, completeChan)
// RPC
if EnableRPC {
// Create closure
eClos := func(terms etf.List) (r etf.Term) {
r = etf.Term(etf.Tuple{etf.Atom("gonode"), etf.Atom("reply"), len(terms)})
return
}
// Provide it to call via RPC with `rpc:call(gonode@localhost, go_rpc, call, [as, qwe])`
err = enode.RpcProvide("go_rpc", "call", eClos)
if err != nil {
log.Printf("Cannot provide function to RPC: %s", err)
}
}
// Wait to stop
<-completeChan
log.Println("node finished")
return
}
func (nk *netKernel) HandleCall(message *etf.Term, from *etf.Tuple) (reply *etf.Term) {
nLog("NET_KERNEL: HandleCall: %#v, From: %#v", *message, *from)
switch t := (*message).(type) {
case etf.Tuple:
if len(t) == 2 {
switch tag := t[0].(type) {
case etf.Atom:
if string(tag) == "is_auth" {
nLog("NET_KERNEL: is_auth: %#v", t[1])
replyTerm := etf.Term(etf.Atom("yes"))
reply = &replyTerm
}
}
}
}
return
}
func runNode() (enode *node.Node) {
enode = node.NewNode(nodeName, nodeCookie)
err := enode.Publish(nodePort)
if err != nil {
log.Printf("Cannot publish: %s", err)
enode = nil
}
eSrv := new(eclusSrv)
enode.Spawn(eSrv)
eClos := func(terms etf.List) (r etf.Term) {
r = etf.Term(etf.Tuple{etf.Atom("enode"), len(terms)})
return
}
err = enode.RpcProvide("enode", "lambda", eClos)
if err != nil {
log.Printf("Cannot provide function to RPC: %s", err)
}
return
}
func main() {
// Initialize new node with given name and cookie
enode := node.NewNode("gonode@localhost", "123")
// Allow node be available on 5588 port
err := enode.Publish(5588)
if err != nil {
log.Fatalf("Cannot publish: %s", err)
}
// Create channel to receive message when main process should be stopped
completeChan := make(chan bool)
// Initialize new instance of gonodeSrv structure which implements Process behaviour
eSrv := new(gonodeSrv)
// Spawn process with one arguments
enode.Spawn(eSrv, completeChan)
// RPC
// Create closure
eClos := func(terms etf.List) (r etf.Term) {
r = etf.Term(etf.Tuple{etf.Atom("gonode"), etf.Atom("reply"), len(terms)})
return
}
// Provide it to call via RPC with `rpc:call(gonode@localhost, go_rpc, call, [as, qwe])`
err = enode.RpcProvide("go_rpc", "call", eClos)
if err != nil {
log.Printf("Cannot provide function to RPC: %s", err)
}
// Wait to stop
<-completeChan
return
}
func (currNd *NodeDesc) ReadMessage(c net.Conn) (ts []etf.Term, err error) {
sendData := func(headerLen int, data []byte) (int, error) {
reply := make([]byte, len(data)+headerLen)
if headerLen == 2 {
binary.BigEndian.PutUint16(reply[0:headerLen], uint16(len(data)))
} else {
binary.BigEndian.PutUint32(reply[0:headerLen], uint32(len(data)))
}
copy(reply[headerLen:], data)
dLog("Write to enode: %v", reply)
return c.Write(reply)
}
switch currNd.state {
case HANDSHAKE:
var length uint16
if err = binary.Read(c, binary.BigEndian, &length); err != nil {
return
}
msg := make([]byte, length)
if _, err = io.ReadFull(c, msg); err != nil {
return
}
dLog("Read from enode %d: %v", length, msg)
switch msg[0] {
case 'n':
sn := currNd.read_SEND_NAME(msg)
// Statuses: ok, nok, ok_simultaneous, alive, not_allowed
sok := currNd.compose_SEND_STATUS(sn, true)
_, err = sendData(2, sok)
if err != nil {
return
}
rand.Seed(time.Now().UTC().UnixNano())
currNd.challenge = rand.Uint32()
// Now send challenge
challenge := currNd.compose_SEND_CHALLENGE(sn)
sendData(2, challenge)
if err != nil {
return
}
case 'r':
sn := currNd.remote
ok := currNd.read_SEND_CHALLENGE_REPLY(sn, msg)
if ok {
challengeAck := currNd.compose_SEND_CHALLENGE_ACK(sn)
sendData(2, challengeAck)
if err != nil {
return
}
dLog("Remote: %#v", sn)
ts = []etf.Term{etf.Term(etf.Tuple{etf.Atom("$go_set_node"), etf.Atom(sn.Name)})}
} else {
err = errors.New("bad handshake")
return
}
}
case CONNECTED:
var length uint32
if err = binary.Read(c, binary.BigEndian, &length); err != nil {
return
}
if length == 0 {
dLog("Keepalive")
sendData(4, []byte{})
return
}
r := &io.LimitedReader{c, int64(length)}
if currNd.flag.isSet(DIST_HDR_ATOM_CACHE) {
var ctl, message etf.Term
if err = currNd.readDist(r); err != nil {
break
}
if ctl, err = currNd.readCtl(r); err != nil {
break
}
dLog("READ CTL: %#v", ctl)
if message, err = currNd.readMessage(r); err != nil {
break
}
dLog("READ MESSAGE: %#v", message)
ts = append(ts, ctl, message)
} else {
msg := make([]byte, 1)
if _, err = io.ReadFull(r, msg); err != nil {
return
}
dLog("Read from enode %d: %#v", length, msg)
switch msg[0] {
case 'p':
ts = make([]etf.Term, 0)
for {
var res etf.Term
if res, err = currNd.readTerm(r); err != nil {
break
}
ts = append(ts, res)
dLog("READ TERM: %#v", res)
}
if err == io.EOF {
err = nil
}
default:
_, err = ioutil.ReadAll(r)
}
}
}
return
}
func (es *eclusSrv) HandleCall(message *etf.Term, from *etf.Tuple) (reply *etf.Term) {
log.Printf("ECLUS_SRV: HandleCall: %#v, From: %#v", *message, *from)
replyTerm := etf.Term(etf.Tuple{etf.Atom("ok"), etf.Atom("eclus_reply"), *message})
reply = &replyTerm
return
}
func (gns *globalNameServer) HandleCall(message *etf.Term, from *etf.Tuple) (reply *etf.Term) {
nLog("GLOBAL_NAME_SERVER: HandleCall: %#v, From: %#v", *message, *from)
replyTerm := etf.Term(etf.Atom("reply"))
reply = &replyTerm
return
}