我正在尝试为演示创建一个简单的两个协议客户端和服务器。但是当我在websocket的客户端初始化中指定两个子协议时，我总是在服务器端获得此消息：
[1363089953:1535] ERR: Req protocol SIGN_IN_OUT_REQUEST_PROTOCOL, GET_REQUEST_PROTOCOL not supported
客户端Javascript代码：
var host = 'ws://10.0.96.32:9000';
var webSocket = {};
var websocketStatus = {};
$(function() {
function webSocketSupported() {
if(window.MozWebSocket) {
window.WebSocket = window.MozWebSocket;
}
return (window.webSocket != null);
}
if(!webSocketSupported) {
$(document).simpledialog2({
mode: 'blank',
headerClose: true,
blankContent :
"<p>Websockets not supported by this browser. How about <a href='http://www.google.com/chrome'>Google Chrome</a>?</p>"+
"<a rel='close' data-role='button' href='#'>Close</a>"
});
} else {
$("#login_form").validate({
rules:{
username: {required: true, minlength: 2},
password: {required: true, minlength: 4}
},
messages:{
username: {required: "Username is required",
minlength: "Username must be atleast 2 characters"},
password: {required: "Password is required",
minlength: "Password must be atleast 4 characters"}
}
});
/** Setting up WebSocket **/
webSocket = new WebSocket(host, 'SIGN_IN_OUT_REQUEST_PROTOCOL', 'GET_REQUEST_PROTOCOL');
webSocket.binaryType = "arraybuffer";
webSocket.onopen = onopen;
webSocket.onmessage = onmessage;
webSocket.onclose = onclose;
webSocket.onerror = onerror;
}
});
function onopen() {
$('#connectionStatus').text("Connected");
$('#connectionStatus').buttonMarkup({theme: 'b'});
$("#connectionStatus").data('icon', 'check');
$("#connectionStatus .ui-icon").addClass("ui-icon-check").removeClass("ui-icon-alert");
$('#login_info').append("Sub-protocol: "+webSocket.protocol+"\n");
}
function onmessage(event) {
var data = new DataView(event.data);
if(data.getUint8(data.byteLength - 1) == 1) {
$('#login_info').append("Login Attempt Successful");
$.mobile.loadPage("mobileApp.html");
$.mobile.changePage("mobileApp.html")
}
else {
$('#login_info').append("Login Attempt Unsuccessful");
$('#username').val("");
$('#password').val("");
}
}
function onclose() {
$('#connectionStatus').text("Connection Closed");
$('#connectionStatus').buttonMarkup({theme: 'a'});
$("#connectionStatus").data('icon', 'alert');
$("#connectionStatus .ui-icon").addClass("ui-icon-alert").removeClass("ui-icon-alert");
}
function onerror() {
$('#connectionStatus').text("Connection Error");
$('#connectionStatus').buttonMarkup({theme: 'a'});
$("#connectionStatus").data('icon', 'alert');
$("#connectionStatus .ui-icon").addClass("ui-icon-alert").removeClass("ui-icon-alert");
}
function initialize() {
$('#login_info').val("");
$('#username').val("");
$('#password').val("");
$('#connectionStatus').text("Connection Closed");
$('#connectionStatus').buttonMarkup({theme: 'a'});
$("#connectionStatus").data('icon', 'alert');
$("#connectionStatus .ui-icon").addClass("ui-icon-alert").removeClass("ui-icon-alert");
}
function sendLoginRequest(event) {
var i = 0;
event.preventDefault();
if($("#login_form").valid()) {
var username = $("#username").val();
var password = $("#password").val();
var loginRequest = new Uint8Array(calculateBufferLength());
loginRequest[i++] = 0x13; //User Accounts IP
loginRequest[i++] = 0x13; //Sign In/Sign Out Request
loginRequest[i++] = 0x07; //Sign In
loginRequest[i++] = username.length;
loginRequest[i++] = password.length;
//Pushing username
for(var j=0; j < username.length; j++) {
loginRequest[i++] = username.charCodeAt(j);
}
//Pushing password
for(var j=0; j < password.length; j++) {
loginRequest[i++] = password.charCodeAt(j);
}
webSocket.send(loginRequest.buffer);
$("#login_info").append("Login request sent with\nUsername: "+username+"\nPassword: "+password+"\n");
}
}
function calculateBufferLength() {
var opIPLength = 1;
var modeLength = 1;
var subModeLength = 1;
var UserNamePasswordlengths = 2;
var userNameLength = $("#username").val().length;
var passwordLength = $("#password").val().length;
return (opIPLength + modeLength + subModeLength + UserNamePasswordlengths + userNameLength + passwordLength);
}
服务器C / C ++代码（Libwebsockets）
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string>
#include <vector>
#include <libwebsockets.h>
using namespace std;
typedef enum {
USER_ACCOUNTS_IP_REQUEST,
MODE,
SUB_MODE,
USER_NAME_LENGTH,
PASSWORD_LENGTH
}user_accounts_ip_request_t;
typedef enum {
USER_ACCOUNTS_IP_RESPONSE,
RESPONSE_IP
}user_accounts_ip_response_t;
int Hex_to_Dec(unsigned char *array, int size);
void sendLoginResponse(struct libwebsocket *wsi, void *in_buffer, size_t bufferlen, struct per_session_data__binary *out_buffer);
void printSocketInfo(struct libwebsocket *wsi, struct libwebsocket_context *currentContext);
struct per_session_data__binary
{
unsigned int len;
unsigned char buf[sizeof(LWS_SEND_BUFFER_PRE_PADDING) + 1024 + sizeof(LWS_SEND_BUFFER_POST_PADDING)];
};
static int callback_http(struct libwebsocket_context *currentContext,
struct libwebsocket *wsi,
enum libwebsocket_callback_reasons reason, void *user,
void *in, size_t len)
{
return 0;
}
static int callback_sign_in_out_request(struct libwebsocket_context *currentContext,
struct libwebsocket *wsi,
enum libwebsocket_callback_reasons reason,
void *user, void *in, size_t len)
{
struct per_session_data__binary *psb = (per_session_data__binary *)user; ////////
switch (reason) {
case LWS_CALLBACK_ESTABLISHED: // just log message that someone is connecting
printf("connection established\n");
break;
case LWS_CALLBACK_PROTOCOL_INIT:
printf("LWS_CALLBACK_PROTOCOL_INIT\n");
break;
case LWS_CALLBACK_CLIENT_CONNECTION_ERROR:
printf("LWS_CALLBACK_CLIENT_CONNECTION_ERROR\n");
break;
case LWS_CALLBACK_CLIENT_FILTER_PRE_ESTABLISH:
printf("LWS_CALLBACK_CLIENT_FILTER_PRE_ESTABLISH\n");
break;
case LWS_CALLBACK_RECEIVE: {
printf("Binary frame received decoding packet...\n");
sendLoginResponse(wsi, in, len, psb);
}
break;
default:
break;
}
return 0;
}
static int callback_get_request(struct libwebsocket_context *currentContext,
struct libwebsocket *wsi,
enum libwebsocket_callback_reasons reason,
void *user, void *in, size_t len)
{
return 0;
}
static struct libwebsocket_protocols protocols[] = {
/* first protocol must always be HTTP handler */
{
"http-only", // name
callback_http, // callback
0 // per_session_data_size
},
{
"SIGN_IN_OUT_REQUEST_PROTOCOL", // protocol name - very important!
callback_sign_in_out_request, // callback
sizeof(struct per_session_data__binary) // we don't use any per session data
},
{
"GET_REQUEST_PROTOCOL",
callback_get_request,
sizeof(struct per_session_data__binary)
},
{
NULL, NULL, 0 /* End of list */
}
};
int main(void) {
// server url will be http://localhost:9000
int port = 9000;
const char *interface = NULL;
struct libwebsocket_context *context;
struct lws_context_creation_info info;
// we're not using ssl
const char *cert_path = NULL;
const char *key_path = NULL;
// no special options
int opts = 0;
info.port = port;
info.iface = interface;
info.protocols = protocols;
info.extensions = libwebsocket_get_internal_extensions();
info.ssl_cert_filepath = cert_path;
info.ssl_private_key_filepath = key_path;
info.ssl_ca_filepath = NULL;
info.gid = -1;
info.uid = -1;
info.options = opts;
info.user = NULL;
//info.ka_time = 0;
//info.ka_probes = 100;
//info.ka_interval= 60;
context = libwebsocket_create_context(&info);
if (context == NULL) {
fprintf(stderr, "libwebsocket init failed\n");
return -1;
}
printf("starting server...\n");
// infinite loop, to end this server send SIGTERM. (CTRL+C)
while (1) {
libwebsocket_service(context, 50);
//printf("after service\n");
// libwebsocket_service will process all waiting events with their
// callback functions and then wait 50 ms.
// (this is a single threaded webserver and this will keep our server
// from generating load while there are not requests to process)
}
libwebsocket_context_destroy(context);
return 0;
}
void sendLoginResponse(struct libwebsocket *wsi, void *in_buffer, size_t bufferlen, struct per_session_data__binary *out_buffer)
{
vector<string> userNames, passwords;
string userName, password;
bool loginValid = false;
int usernameLength, passwordLength;
int usernamePos, passwordPos;
userNames.push_back("Nautel");
passwords.push_back("password");
//Print Login Request Data
char* loginRequest = (char*) in_buffer;
usernameLength = loginRequest[USER_NAME_LENGTH];
passwordLength = loginRequest[PASSWORD_LENGTH];
usernamePos = PASSWORD_LENGTH + 1;
passwordPos = usernamePos + usernameLength;
//Get Username
for(int i=usernamePos; i < (usernamePos+usernameLength); i++) {
userName.push_back(loginRequest[i]);
}
//Get Password
for(int i=passwordPos; i < (passwordPos + passwordLength); i++) {
password.push_back(loginRequest[i]);
}
printf("Username: %s Password: %s\n", userName.c_str(), password.c_str());
for(int i=0; i < userNames.size(); i++) {
loginValid = (!userName.compare(userNames[i]) && !password.compare(passwords[i]));
if(loginValid) break;
}
out_buffer->buf[USER_ACCOUNTS_IP_RESPONSE] = 0x13;
out_buffer->buf[RESPONSE_IP] = (loginValid) ? 0x01 : 0x00;
out_buffer->len = 2;
libwebsocket_write(wsi, out_buffer->buf, out_buffer->len, LWS_WRITE_BINARY);
}
void printSocketInfo(struct libwebsocket *wsi, struct libwebsocket_context *currentContext){
char name[128];
int name_len=sizeof(name);
char rip[16];
int rip_len= sizeof(rip);
int fd;
fd = libwebsocket_get_socket_fd(wsi);
libwebsockets_get_peer_addresses (currentContext, wsi, fd, name, name_len, rip, rip_len);
printf("Name: %s, IP: %s\n", name, rip);
}
是否可以让客户端具有单个服务器支持的多个子协议，反之亦然。或者我是否需要从客户端到服务器的多个websocket连接以用于不同的协议。
此致 Shreyas
答案 0 :(得分：1)
WebSocket客户端可以宣布支持多个WebSocket子协议，但服务器必须从客户端公布的列表中选择一个子协议（它支持）。
答案 1 :(得分：0)
在握手期间，支持的子协议服务器端列表将发送到客户端。客户端也发送其列表。 他们必须至少有一个共同的子协议。
您可以实施自己的子协议或使用现有的ones。
例如，对于使用libwebsockets库（C / C ++）和javascript websocket客户端的websocket服务器，如果您实现自己的子协议：
服务器端：
static struct libwebsocket_protocols protocols[] = {
{
"http-only",
callback_http,
0
},
{
"MySubProtocol",
dedicated_callback_function,
sizeof(struct per_session_data__binary)
}
}
客户端：
var exampleSocket = new WebSocket("ws://www.example.com/socketserver", "MySubProtocol");