v0.0.1

go.mod

@@ -0,0 +1,3 @@
+module antegr.al/netfunnnel
+
+go 1.20

netfunnel.go

@@ -0,0 +1,194 @@
+package netfunnel
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type Client struct {
+	ApiEndpoint   string        // the netfunnel server endpoint. you should know that the netfunnel endpoint is different by the api server.
+	RetryInterval time.Duration // if waitlist is full, delay time to check again. (recommend: 1s)
+}
+
+// Check waitlist status from the server with the key.
+//
+// if success, return 200.
+func (t *Client) CheckWaitlist(key string) (int, error) {
+	// TODO: chkEnter에 대한 정확한 params 값 확인 필요
+	params := url.Values{}
+	params.Add("opcode", "5002")
+	params.Add("key", key)
+	params.Add("nfid", "0")
+	params.Add("prefix", "NetFunnel.gRtype=5002;")
+	params.Add("ttl", "0")
+	params.Add("js", "yes")
+
+	apiurl := appendStr(t.ApiEndpoint, "?", params.Encode(), "&", fmt.Sprint(time.Now().UnixMilli()))
+	resp, err := http.Get(apiurl)
+	if err != nil {
+		return -1, errors.New("failed to connect to the netfunnel server. (in CheckWaitlist)")
+	}
+
+	return resp.StatusCode, nil
+}
+
+// The netfunnel ticket struct.
+//
+// if you need, you can to get ticket from the server by calling GetTicket() method.
+// and if you can requesting another api server (using netfunnel), maybe you need this ID of the ticket.
+type Ticket struct {
+	Id    string
+	Ip    string
+	Key   string
+	Nnext int
+	Nwait int
+	Port  int
+	Tps   int
+	Ttl   int
+}
+
+// Getting ticket from the server
+func (t *Client) GetTicket() (Ticket, error) {
+	params := url.Values{}
+	params.Add("opcode", "5101")
+	params.Add("nfid", "0")
+	params.Add("prefix", "NetFunnel.gRtype=5101;")
+	params.Add("sid", "service_1")
+	params.Add("aid", "act_1")
+	params.Add("js", "yes")
+
+	// Requesting to the server
+	apiurl := appendStr(t.ApiEndpoint, "?", params.Encode(), "&", fmt.Sprint(time.Now().UnixMilli()))
+	resp, err := http.Get(apiurl)
+	if err != nil {
+		return Ticket{}, errors.New("failed to connect to the netfunnel server")
+	}
+
+	// Reading response body
+	respBytes, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return Ticket{}, errors.New("failed to read response body")
+	}
+
+	// parsing ticket from response body
+	ticket, err := parseTicketStr(string(respBytes))
+	if err != nil {
+		return Ticket{}, err
+	}
+
+	// Check HTTP Status Code
+	switch resp.StatusCode {
+	case 200:
+		// Success (waitlist is empty)
+		break
+	case 201:
+		for {
+			resHttpCode, err := t.CheckWaitlist(ticket.Key)
+			if err != nil {
+				return Ticket{}, err
+			}
+			if resHttpCode == 200 {
+				// Success (waited, but now it's your turn)
+				break
+			}
+			time.Sleep(t.RetryInterval)
+		}
+	default:
+		return Ticket{}, fmt.Errorf("unexpected HTTP Status Code. (HTTP %d)", resp.StatusCode)
+	}
+
+	return ticket, nil
+}
+
+// Dispatching ticket to the server
+func (t *Client) DispatchTicket(ticket *Ticket) error {
+	params := url.Values{}
+	params.Add("opcode", "5004")
+	params.Add("key", ticket.Key)
+	params.Add("nfid", "0")
+	params.Add("prefix", "NetFunnel.gRtype=5004;")
+	params.Add("sid", "service_1")
+	params.Add("aid", "act_1")
+	params.Add("js", "yes")
+
+	// Requesting to the server
+	apiurl := appendStr(t.ApiEndpoint, "?", params.Encode(), "&", fmt.Sprint(time.Now().UnixMilli()))
+	resp, err := http.Get(apiurl)
+	if err != nil {
+		return errors.New("failed to connect to the netfunnel server")
+	}
+
+	switch resp.StatusCode {
+	case 200:
+		return nil
+	default:
+		return fmt.Errorf("unexpected HTTP Status Code. (HTTP %d)", resp.StatusCode)
+	}
+}
+
+// Parsing netfunnel ticket response body. it return Ticket.
+func parseTicketStr(body string) (Ticket, error) {
+	scriptVars := make(map[string]string)
+
+	// parsing response body. it expects to be a javascript variable declaration.
+	for _, v := range strings.Split(body, ";") {
+		kvArray := strings.SplitN(v, "=", 2)
+		scriptVars[strings.Trim(kvArray[0], " ")] = strings.Trim(kvArray[1], " ")
+	}
+
+	// check NetFunnel.gControl.result exists
+	if scriptVars["NetFunnel.gControl.result"] == "" {
+		return Ticket{}, errors.New("failed to parse response body: Cannot find 'NetFunnel.gControl.result' key")
+	}
+
+	id := strings.Trim(scriptVars["NetFunnel.gControl.result"], "'") // remove single quotes
+
+	// parsing NetFunnel.gControl.result
+	// example: <int>:<int>:ip=nf.example.com&key=<string>&nnext=<int>&nwait=<int>&port=<int>&tps=<int>&ttl=<int>
+	val, err := url.ParseQuery(strings.SplitN(id, ":", 2)[2]) // we need only "ip=nf.example.com&key=<string>&nnext=<int>&nwait=<int>&port=<int>&tps=<int>&ttl=<int>"
+	if err != nil {
+		return Ticket{}, fmt.Errorf("failed to parse response body (url.ParseQuery failed): %s", err)
+	}
+
+	val_nnext, err := strconv.Atoi(val.Get("nnext"))
+	if err != nil {
+		return Ticket{}, fmt.Errorf("failed to parse response body (Atoi Failed, in nnext): %s", err)
+	}
+
+	val_nwait, err := strconv.Atoi(val.Get("nwait"))
+	if err != nil {
+		return Ticket{}, fmt.Errorf("failed to parse response body (Atoi Failed, in nwait): %s", err)
+	}
+
+	val_port, err := strconv.Atoi(val.Get("port"))
+	if err != nil {
+		return Ticket{}, fmt.Errorf("failed to parse response body (Atoi Failed, in port): %s", err)
+	}
+
+	val_tps, err := strconv.Atoi(val.Get("tps"))
+	if err != nil {
+		return Ticket{}, fmt.Errorf("failed to parse response body (Atoi Failed, in tps): %s", err)
+	}
+
+	val_ttl, err := strconv.Atoi(val.Get("ttl"))
+	if err != nil {
+		return Ticket{}, fmt.Errorf("failed to parse response body (Atoi Failed, in ttl): %s", err)
+	}
+
+	return Ticket{
+		Id:    id,
+		Ip:    val.Get("ip"),
+		Key:   val.Get("key"),
+		Nnext: val_nnext,
+		Nwait: val_nwait,
+		Port:  val_port,
+		Tps:   val_tps,
+		Ttl:   val_ttl,
+	}, nil
+}

util.go

@@ -0,0 +1,14 @@
+package netfunnel
+
+import (
+	"bytes"
+)
+
+func appendStr(str ...string) string {
+	var buf bytes.Buffer
+	for _, v := range str {
+		buf.WriteString(v)
+	}
+
+	return buf.String()
+}