웹소켓 API¶

Oasis는 웹소켓 서버와 클라이언트를 지원합니다.

웹소켓 서버는 createHttpWsService API를 이용하여 HTTP 서버의 특정 URL에 붙혀서도 사용 가능합니다.

헤더 파일¶

OasisNet.h

WsEventDelegate 인터페이스¶

Oasis 웹소켓 서비스는 사용자가 WsEventDelegate 인터페이스로 부터 유도된 객체를 통하여 웹소켓 이벤트를 처리합니다.

class WsEventDelegate : public std::enable_shared_from_this<WsEventDelegate>
{
public:
    WsEventDelegate();
    virtual ~WsEventDelegate();

public: 
    virtual void onOpen(const WsEventRef &evt);
    virtual void onMessage(const WsEventRef &evt);
    virtual void onError(const WsEventRef &evt);
    virtual void onClose(const WsEventRef &evt);
};

아래는 Echo 서버의 경우 onMessage 처리 예입니다.

void EchoWsEventDelegate::onMessage(const WsEventRef &evt)  
{
  if(wsEventMessageType(evt) == kWsMessageText) {
    std::vector<uint8_t> data;
    if(wsEventData(evt, data) > 0) {
      std::string str = "Echo: ";
      str += std::string(data.data(), data.data()+data.size());
      wsSendText(evt, str.c_str());
    }
  }
}

WsEvent¶

메세지 타입을 아래와 같습니다.

상태 코드는 아래와 같습니다.

서버 함수¶

웹소켓 서버 생성에 필요한 key-value map은 아래와 같습니다.

TLS를 이용한 보안 웹소켓 서버를 생성할 경우, 아래 key-value map이 추가로 필요합니다.

클라이언트 함수¶

wsOpenConnection 에 필요한 key-value map 은 아래와 같습니다.

예제¶

아래는 웹소켓 서버 예입니다.

#include "OasisAPI.h"
#include "OasisLog.h"
#include "OasisWeb.h"

#include <thread>
#include <mutex>
#include <memory>
#include <condition_variable>

#define DLOG_THIS   0x00080000

#undef DLOG_FLAGS
#define  DLOG_FLAGS (DLOG_FLAGS_DEFAULT|DLOG_THIS/**/)

#undef DLOG_TAG
#define DLOG_TAG "WSS"

#define USE_RSA 1
#define USE_ECDSA 0
#define USE_DSS 0

using namespace oasis;

static bool continuing = true;


//for WebSocket upstream
class MyWsEventDelegate : public WsEventDelegate
{
public:
    MyWsEventDelegate() {}
    virtual ~MyWsEventDelegate() {}

public: 
    virtual void onOpen(const WsEventRef &evt) {
        DLOG(DLOG_THIS, "Open\n");
    }

    virtual void onMessage(const WsEventRef &evt)  {
        DLOG(DLOG_THIS, "Message\n");

        if(wsEventMessageType(evt) == kWsMessageText) {
            std::vector<uint8_t> data;
            if(wsEventData(evt, data) > 0) {
                std::string str(data.data(), data.data()+data.size());
                wsSendText(evt, str.c_str());
            }
        }
    }

    virtual void onError(const WsEventRef &evt) {
        DLOG(DLOG_THIS, "Error\n");
    }

    virtual void onClose(const WsEventRef &evt) {
        DLOG(DLOG_THIS, "Close\n");
    }
};


void cancel_handler(int signum)
{
    continuing = false;
}


int main(int argc, char* argv[])
{
    int32_t c, err;
    uint16_t port;
    std::thread t3;
    key_value_map_t parameters, fields;


    if(argc < 2) {
        printf("USAGE: %s <port number>\n", argv[0]);
        return 255;
    }

    port = (uint16_t)atoi(argv[1]);
    if(port == 0) {
        printf("USAGE: %s <port number>\n", argv[0]);
        return 255;
    }

    signal(SIGINT, cancel_handler);

    parameters["offs-disable"] = "1";
    if(oasis::initialize(parameters) < 0) {
        DLOG(DLOG_ERROR, "Oasis init failed\n");
        return -1;
    }

    parameters.clear();

    parameters["port"] = std::to_string(port);
    parameters["ca-certs-file-path"] = "/data/certs/RootCA.pem";

#if USE_RSA
        parameters["cert-file-path"] = "/data/certs/fullchain.pem";
        parameters["pkey-file-path"] = "/data/certs/privkey.pem";
#elif USE_ECDSA
        parameters["cert-file-path"] = "/data/certs/ec_fullchain.pem";
        parameters["pkey-file-path"] = "/data/certs/ec_pkey.pem";
#elif USE_DSS
        parameters["cert-file-path"] = "/data/certs/dsa_fullchain.pem";
        parameters["pkey-file-path"] = "/data/certs/dsa_pkey.pem";
#else
        #error "No certficates!"
#endif

    std::shared_ptr<MyWsEventDelegate> delegate = std::make_shared<MyWsEventDelegate>();

    WsServerRef server = createWsServer(parameters, delegate);
    if(!server) {
        DLOG(DLOG_ERROR, "failed to create a websocket server\n");
        return -1;
    }

    if(startWsServer(server) < 0) {
        DLOG(DLOG_ERROR, "start failed\n");
        goto done;
    }

    do {
    usleep(10000);
    } while (continuing);

    stopWsServer(server);

done:

    destroyWsServer(server);

    oasis::finalize();

    return 0;
}

아래는 웹소켓 클라이언트 예입니다.

#include "OasisAPI.h"
#include "OasisLog.h"
#include "OasisWeb.h"

#include <thread>
#include <mutex>
#include <memory>
#include <condition_variable>

#define DLOG_THIS   0x00080000

#undef DLOG_FLAGS
#define  DLOG_FLAGS (DLOG_FLAGS_DEFAULT|DLOG_THIS/**/)

#undef DLOG_TAG
#define DLOG_TAG "WSC"


using namespace oasis;


static TTYRaw tty_;

static bool continuing = true;
static bool ws_closed = false;


//for WebSocket upstream
class MyWsEventDelegate : public WsEventDelegate
{
public:
    MyWsEventDelegate() {}
    virtual ~MyWsEventDelegate() {}

public: 
    virtual void onOpen(const WsEventRef &evt) {
        DLOG(DLOG_THIS, "Open\n");
    }

    virtual void onMessage(const WsEventRef &evt)  {
        DLOG(DLOG_VERBOSE, "Message\n");
        if(wsEventMessageType(evt) == kWsMessageText) {
            std::string str;
            wsEventText(evt, str);
            DLOG0(DLOG_THIS, "==> %s\n", str.c_str());
        }
    }

    virtual void onError(const WsEventRef &evt) {
        DLOG(DLOG_THIS, "Error: %d\n", wsEventStatusCode(evt));
    }

    virtual void onClose(const WsEventRef &evt) {
        DLOG(DLOG_THIS, "Close: %d\n", wsEventStatusCode(evt));
        ws_closed = true;
    }
};

void cancel_handler(int signum)
{
    continuing = false;
}


int main(int argc, char* argv[])
{
    int32_t err;

    int32_t status_code;
    std::string reason_string;
    std::string content_type; 

    int32_t wait_count = 0;

    key_value_map_t parameters, fields;

    std::string url = "wss://echo.websocket.org/";

    if(argc >= 2) {
        url = argv[1];
    }

    signal(SIGINT, cancel_handler);

    parameters["offs-disable"] = "1";
    if(oasis::initialize(parameters) < 0) {
        DLOG(DLOG_ERROR, "Oasis init failed\n");
        return -1;
    }

    parameters.clear();

    parameters["ca-certs-file-path"] = "/data/certs/cacerts.pem\x0a/data/certs/RootCA.pem";
    parameters["cert-file-path"] = "/data/certs/client_fullchain.pem";
    parameters["pkey-file-path"] = "/data/certs/client_privkey.pem";

    parameters["tls-disable-certificate-validation"] = "1";
    parameters["tls-use-sni"] = "1";

    //websocket-protocols
    parameters["websocket-fragment-size-max"] = std::to_string(8192);

    WsConnectionRef conn;
    char buffer[512];

    std::shared_ptr<MyWsEventDelegate> delegate = std::make_shared<MyWsEventDelegate>();

    conn = wsOpenConnection(url.c_str(), parameters, delegate, 10000);
    if(conn) {

        DLOG(DLOG_THIS, "connected.\n");

        strpcy(buffer, "hello, world!");
        wsSendText(conn, (const char*)buffer);

        DLOG(DLOG_THIS, "closing...\n");
        wsCloseConnection(conn);

        //need sometime to be closed.
        int32_t max_wait = 20; //2 seconds
        do {
            usleep(10000);
        } while(ws_closed == false && max_wait-- > 0);

    }

    conn = nullptr;

    oasis::finalize();

    return 0;
}