一直在写C#代码好多年不写C语言代码了，记录一下之前某个项目里用C写的一个websocket服务，用C的优势是写的东西体积小性能高，但是写业务的话还得用C#、Java之类的语言，不然会折腾死人。。。
用Visual Studio新建一个C++（因为不能直接建C语言项目）项目，我演示就创建一个控制台项目。项目创建完后首先要添加socket编程需要的依赖库ws2_32.lib，添加方式如下图
也可以在代码文件里添加这句代码：#pragma comment(lib,"Ws2_32.lib")，接着添加b64、cJSON、sha1依赖库。
添加完成后就可以开始写代码了，说句题外话，Visual Studio写C语言最好把SDL检查也关掉。
新建一个wsserver.h头文件，头文件相关定义代码如下
#pragma once
#include <WinSock2.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <windef.h>
#include <stdlib.h>
#include "sha1.h"
#include "b64.h"
#include "cJSON.h"
typedef enum FrameType
{
frameType_continuation,
frameType_text,
frameType_binary,
frameType_connectionClose,
frameType_ping,
frameType_pong
} FrameType;
typedef enum FrameState
{
frameState_init, // 未读取任何字节
frameState_firstByte, // 已读取首字节FIN、RSV、opcode
frameState_mask, // 已读取掩码
frameState_7bitLength, // 已读取7bit长度
frameState_16bitLengthWait, // 等待读取16bit长度
frameState_63bitLengthWait, // 等待读取63bit长度
frameState_16bitLength, // 已读取16bit长度
frameState_63bitLength, // 已读取63bit长度
frameState_maskingKey, // 已读取Masking-key
frameState_readingData, // 正在读取载荷数据
frameState_success, // 读取完毕
frameState_failure // 读取错误
} FrameState;
typedef struct WsFrame
{
FrameState state;
bool FIN;
FrameType frameType;
uint8_t mask[4];
unsigned char* buff; // 数据存放的空间
uint64_t buffSize; // 当前申请的buff大小
uint64_t handledLen; // 已处理的帧长度
uint64_t headerLen; // 帧头长度 只有在state为'已读取掩码'及之后才有意义
uint64_t payloadLen; // 载荷长度 只有在state为'已读取xbit长度'后才有意义
struct WsFrame* next; // 下一帧的指针
} WsFrame;
void initWsFrameStruct(WsFrame* wsFrame);
char* convertToWebSocketFrame(const char* data, FrameType type, size_t len, size_t* newLen);
int readWebSocketFrameStream(WsFrame* wsFrame, const char* buff, int len);
void freeWebSocketFrame(WsFrame* wsFrame);
int wsShakeHands(const char* recvBuff, int recvLen, SOCKET socket, const char* path);
int wsFrameSend(SOCKET socket, const char* buff, int len, FrameType type);
void wsFrameSendToAll(const char* buff, int len, FrameType type);
int serverStart(const char* address, u_short port, const char* path);
void serverStop(void);
新建一个wsserver.c代码文件，我们一步一步的来实现这些方法。
首先是serverStart方法，顾名思义，启动ws服务，第一个参数是地址（一般传本机IP），第二个参数是要监听的端口，第三个参数是路径，完整代码如下
#include "wsserver.h"
#include <time.h>
#define _CRT_SECURE_NO_WARNINGS
#define _WINSOCK_DEPRECATED_NO_WARNINGS
typedef enum
{
socketProtocol,
websocketProtocol
} Protocol;
typedef struct
{
Protocol protocol;
SOCKET socket;
WsFrame wsFrame;
} Client;
#define MAX_CLIENT_NUM FD_SETSIZE
static struct
{
int total;
Client clients[MAX_CLIENT_NUM];
} clientSockets;
static SOCKET serverSocket;
// 打印日志
void printLog(const char* type, const char* format, ...)
{
char buff[512] = { 0 };
va_list arg;
va_start(arg, format);
vsnprintf(buff, sizeof(buff) - 1, format, arg);
va_end(arg);
char rbuf[512] = { 0 };
time_t log_time = time(NULL);
struct tm* tm_log = localtime(&log_time);
printf("[%04d-%02d-%02d %02d:%02d:%02d] ", tm_log->tm_year + 1900, tm_log->tm_mon + 1, tm_log->tm_mday, tm_log->tm_hour, tm_log->tm_min, tm_log->tm_sec);
snprintf(rbuf, 512, "%s->%s\n", type, buff);
printf(rbuf);
}
char* UTF8ToGBK(const char* str)
{
// GB18030代码页
const int CODE_PAGE = 54936;
int n = MultiByteToWideChar(CP_UTF8, 0, str, -1, NULL, 0);
wchar_t u16str[10000];
MultiByteToWideChar(CP_UTF8, 0, str, -1, u16str, n);
n = WideCharToMultiByte(CODE_PAGE, 0, u16str, -1, NULL, 0, NULL, NULL);
char* gbstr = malloc(n + 1);
WideCharToMultiByte(CODE_PAGE, 0, u16str, -1, gbstr, n, NULL, NULL);
return gbstr;
}
char* GBKToUTF8(const char* str)
{
const int CODE_PAGE = 54936;
int n = MultiByteToWideChar(CODE_PAGE, 0, str, -1, NULL, 0);
wchar_t u16str[10000];
MultiByteToWideChar(CODE_PAGE, 0, str, -1, u16str, n);
n = WideCharToMultiByte(CP_UTF8, 0, u16str, -1, NULL, 0, NULL, NULL);
char* u8str = malloc(n + 1);
WideCharToMultiByte(CP_UTF8, 0, u16str, -1, u8str, n, NULL, NULL);
return u8str;
}
int serverStart(const char* address, u_short port, const char* path)
{
// 调用 WSAStartup() 函数进行初始化，并指明要使用的版本号。
WSADATA wsaData;
// WSAStartup 函数启动进程使用 Winsock DLL。
int iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
if (iResult != 0)
{
printLog("ServerStart", "WSAStartup failed");
return -1;
}
struct sockaddr_in sockAddr;
// ZeroMemory 宏 等价于 memset((buf),0,(BUF_SIZE))
ZeroMemory(&sockAddr, sizeof(sockAddr));
sockAddr.sin_family = PF_INET; // 等价于 AF_INET TCP UDP etc..
sockAddr.sin_addr.s_addr = inet_addr(address);
sockAddr.sin_port = htons(port);
// 构建一个socket对象
serverSocket = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if (serverSocket == INVALID_SOCKET)
{
printLog("ServerStart","Error at socket(): %d", WSAGetLastError());
WSACleanup();
return -1;
}
// 给socket绑定地址
if (bind(serverSocket, (SOCKADDR*)&sockAddr, sizeof(SOCKADDR)) == SOCKET_ERROR)
{
printLog("ServerStart", "Bind failed with error: %d", WSAGetLastError());
closesocket(serverSocket);
WSACleanup();
return -1;
}
// 开始启动监听
if (listen(serverSocket, SOMAXCONN) == SOCKET_ERROR)
{
printLog("ServerStart", "Listen failed with error: %d", WSAGetLastError());
closesocket(serverSocket);
WSACleanup();
return -1;
}
clientSockets.total = 0;
DWORD dwThreadId;
// 创建线程开始接收socket数据
HANDLE hHandle = CreateThread(NULL, 0, (void*)receiveComingData, (PVOID)path, 0, &dwThreadId);
return 0;
}
serverStart方法中最后创建线程开始接收socket数据的方法receiveComingData代码
void receiveComingData(const char* path)
{
#define RECV_BUFLEN 0X40000
char recvbuf[RECV_BUFLEN];
int iResult;
int ret;
fd_set fdread;
struct timeval tv = { 1, 0 };
receivingDataLoop:
FD_ZERO(&fdread); // 清空socket集合
FD_SET(serverSocket, &fdread); // 设置socket数据读取集合
for (int i = 0; i < clientSockets.total; i++)
{
FD_SET(clientSockets.clients[i].socket, &fdread);
}
// 检查socket是否有数据可读
ret = select(0, &fdread, NULL, NULL, &tv);
if (ret == 0)
{
goto receivingDataLoop; // select的等待时间到达，开始下一轮等待
}
// 检查socket是否在这个集合里
if (FD_ISSET(serverSocket, &fdread))
{
acceptConnect(); // 处理socket连接
}
for (int i = 0; i < clientSockets.total; i++)
{
Client* client = &clientSockets.clients[i];
if (!FD_ISSET(client->socket, &fdread))
{
continue;
}
// 接收数据
iResult = recv(client->socket, recvbuf, RECV_BUFLEN, 0);
if (iResult > 0)
{
printLog("receiveComingData", "Bytes received: %d", iResult);
// 协议升级
if (client->protocol == socketProtocol)
{
int result = wsShakeHands(recvbuf, iResult, client->socket, path);
if (result != 0)
{
removeClient(i--);
}
else
{
client->protocol = websocketProtocol;
initWsFrameStruct(&client->wsFrame); // 初始化ws帧结构
}
}
// WebSocket通信
else if (client->protocol == websocketProtocol)
{
int result = wsClientDataHandle(recvbuf, iResult, client);
if (result == -1)
{
removeClient(i--);
}
}
}
else
{
if (iResult == 0)
{
// 客户端礼貌的关闭连接
printLog("receiveComingData", "Connection closing...");
}
else
{
// 客户端异常关闭连接等情况
printLog("receiveComingData", "Recv failed: %d", WSAGetLastError());
}
removeClient(i--);
}
}
goto receivingDataLoop;
}
receiveComingData方法里处理socket协议升级的代码
// 不区分大小写的比较字符串，相等返回true
bool stricasecmp(const char* a, const char* b)
{
do
{
if (*a == '\0' && *b == '\0')
return true;
} while (tolower(*a++) == tolower(*b++));
return false;
}
// 不区分大小写的比较字符串，n个字符内（包括n）相等返回true
bool strnicasecmp(const char* a, const char* b, unsigned n)
{
do
{
if (n-- == 0 || (*a == '\0' && *b == '\0'))
return true;
} while (tolower(*a++) == tolower(*b++));
return false;
}
int getSecWebSocketAcceptKey(const char* key, char* b64buff, int len)
{
SHA1_CTX ctx;
unsigned char hash[20], buff[512];
if (strlen(key) > 256)
{
return -1;
}
sprintf(buff, "%s%s", key, "258EAFA5-E914-47DA-95CA-C5AB0DC85B11");
SHA1Init(&ctx);
SHA1Update(&ctx, buff, strlen(buff));
SHA1Final(hash, &ctx);
const char* base64 = b64_encode(hash, sizeof(hash));
strncpy(b64buff, base64, len - 1);
b64buff[len - 1] = '\0';
free((void*)base64);
return 0;
}
// 校验WebSocket握手的HTTP头，失败返回NULL，校验成功顺带返回Sec-WebSocket-Key，记得free
char* verifyHandshakeHeaders(const char* str, size_t len)
{
char* secKey = NULL;
char a[1024], b[1024];
bool connection, upgrade, version, key;
connection = upgrade = version = key = false;
if (strcmp(str + len - 4, "\r\n\r\n") != 0)
{
printLog("verifyHandshakeHeaders","HTTP header does not end with '\\r\\n\\r\\n'");
return NULL;
}
const char* cur1 = strstr(str, "\r\n") + 2;
const char* cur2;
while ((cur2 = strstr(cur1, "\r\n")) != cur1)
{
cur2 += 2; // 跳过\r\n
const char* colon = strchr(cur1, ':');
if (colon == NULL || colon >= cur2)
{
printLog("verifyHandshakeHeaders", "Unexpected HTTP header");
break;
}
if (sscanf(cur1, "%[^:]:%s", a, b) != 2)
{
printLog("verifyHandshakeHeaders", "HTTP header parsing failed");
break;
}
if (stricasecmp(a, "connection"))
{
connection = true;
}
else if (stricasecmp(a, "upgrade"))
{
if (!stricasecmp(b, "websocket"))
{
printLog("verifyHandshakeHeaders", "Unexpected value '%s' of Upgrade filed", b);
break;
}
upgrade = true;
}
else if (stricasecmp(a, "Sec-WebSocket-Version"))
{
if (!stricasecmp(b, "13"))
{
printLog("verifyHandshakeHeaders","Unexpected value '%s' of Sec-WebSocket-Version filed", b);
break;
}
version = true;
}
else if (stricasecmp(a, "Sec-WebSocket-Key"))
{
if (!key)
{
key = true;
secKey = malloc(strlen(b) + 1);
strcpy(secKey, b);
}
}
cur1 = cur2;
}
if (!(connection && upgrade && version && key))
{
printLog("verifyHandshakeHeaders", "Missing necessary fields");
if (key) free((void*)secKey); // 释放申请的内存
return NULL;
}
return secKey;
}
int wsShakeHands(const char* recvBuff, int recvLen, SOCKET socket, const char* path)
{
#define RECV_BUFLEN 0X40001
#define HTTP_MAXLEN 1536
#define HTTP_400 "HTTP/1.1 400 Bad Request\r\n\r\n"
// HTTP握手包太长
if (recvLen > HTTP_MAXLEN)
{
send(socket, HTTP_400, strlen(HTTP_400), 0);
printLog("wsShakeHands","Request too long");
return -1;
}
// 注：recvBuff不以'\0'结尾
char resText[HTTP_MAXLEN + 1];
memcpy(resText, recvBuff, recvLen);
resText[recvLen] = '\0';
char requestLine[512];
sprintf(requestLine, "GET %s%s HTTP/1.1\r\n", (strlen(path) == 0 || path[0] != '/') ? "/" : "", path);
// 注：路径部分也被不区分大小写的比较
if (!strnicasecmp(resText, requestLine, strlen(requestLine)))
{
send(socket, HTTP_400, strlen(HTTP_400), 0);
printLog("wsShakeHands","Unexpected request line");
printLog("wsShakeHands", resText);
return -1;
}
const char* secKey = verifyHandshakeHeaders(resText, recvLen);
if (!secKey)
{
send(socket, HTTP_400, strlen(HTTP_400), 0);
return -1;
}
// 获取Sec-WebSocket-Accept
char acptBuff[128];
getSecWebSocketAcceptKey(secKey, acptBuff, sizeof(acptBuff));
printLog("wsShakeHands","Sec-WebSocket-Key is '%s'", secKey);
printLog("wsShakeHands", "Sec-WebSocket-Accept is '%s'", acptBuff);
free((void*)secKey); // 释放secKey
// 协议升级
char resBuff[256];
// 注：当前的CORS设置可能会导致安全问题
// 注：响应中没有包含Sec-Websocket-Protocol头，代表不接受任何客户端请求的ws扩展
const char resHeader[] =
"HTTP/1.1 101 ojbk\r\n"
"Connection: Upgrade\r\n"
"Upgrade: websocket\r\n"
"Sec-WebSocket-Accept: %s\r\n"
"Access-Control-Allow-Origin: *\r\n"
"\r\n"
;
int resLen = sprintf(resBuff, resHeader, acptBuff);
// Send data to the client
int iSendResult = send(socket, resBuff, resLen, 0);
if (iSendResult == SOCKET_ERROR)
{
return -1;
}
printLog("wsShakeHands","Bytes sent: %d", iSendResult);
printLog("wsShakeHands","WebSocket handshake succeeded");
return 0;
}
receiveComingData方法里处理websocket数据的方法wsClientDataHandle代码
int readWebSocketFrameStream(WsFrame* wsFrame, const char* buff, int len)
{
if (wsFrame->buff == NULL)
{
wsFrame->buff = malloc(len);
wsFrame->buffSize = len;
memcpy(wsFrame->buff, buff, len);
}
else
{
char* copyStartAddr;
int requiedLen = wsFrame->buffSize + len;
wsFrame->buff = realloc((void*)wsFrame->buff, requiedLen);
copyStartAddr = wsFrame->buff + wsFrame->buffSize;
wsFrame->buffSize = requiedLen;
memcpy(copyStartAddr, buff, len);
}
// 消耗的数据量
int consumed = 0;
stateTransitionBegin:
switch (wsFrame->state)
{
case frameState_init:
if (wsFrame->buffSize < 1)
{
return consumed;
}
wsFrame->FIN = !!(wsFrame->buff[0] & 0X80);
// RSV位不全为0，存在扩展协议，服务器不处理扩展协议
if ((wsFrame->buff[0] & 0X70) != 0)
{
wsFrame->state = frameState_failure;
break;
}
int opcode = wsFrame->buff[0] & 0X0F;
if (opcode == 0X0)
{
wsFrame->frameType = frameType_continuation;
}
else if (opcode == 0X1)
{
wsFrame->frameType = frameType_text;
}
else if (opcode == 0X2)
{
wsFrame->frameType = frameType_binary;
}
else if (opcode == 0X8)
{
wsFrame->frameType = frameType_connectionClose;
}
else if (opcode == 0X9)
{
wsFrame->frameType = frameType_ping;
}
else if (opcode == 0XA)
{
wsFrame->frameType = frameType_pong;
}
else
{
wsFrame->state = frameState_failure;
break;
}
consumed += 1;
wsFrame->handledLen += 1;
wsFrame->headerLen += 1;
wsFrame->state = frameState_firstByte;
break;
case frameState_firstByte:
if (wsFrame->buffSize < 2)
{
return consumed;
}
// 标准规定客户端传入帧的掩码位必须不为0
if ((wsFrame->buff[1] & 0X80) == 0)
{
wsFrame->state = frameState_failure;
}
wsFrame->state = frameState_mask;
break;
case frameState_mask:
if (wsFrame->buffSize < 2)
{
return consumed;
}
uint8_t payloadLen = wsFrame->buff[1] & 0X7F;
// frame-payload-length-7
if (payloadLen < 126)
{
wsFrame->payloadLen = payloadLen;
wsFrame->state = frameState_7bitLength;
}
else if (payloadLen == 126)
{
wsFrame->state = frameState_16bitLengthWait;
}
else if (payloadLen == 127)
{
wsFrame->state = frameState_63bitLengthWait;
}
consumed += 1;
wsFrame->headerLen += 1;
wsFrame->handledLen += 1;
break;
case frameState_7bitLength:
// 2字节共有字段 + 0字节附加长度字段 + 4字节掩码
if (wsFrame->buffSize < 6)
{
return consumed;
}
for (int i = 0; i < 4; i++)
{
wsFrame->mask[i] = wsFrame->buff[i + 2];
}
consumed += 4;
wsFrame->headerLen += 4;
wsFrame->handledLen += 4;
wsFrame->state = frameState_maskingKey;
break;
case frameState_16bitLengthWait:
if (wsFrame->buffSize < 4)
{
return consumed;
}
wsFrame->payloadLen = ((uint16_t)wsFrame->buff[2] << 8) + (uint16_t)wsFrame->buff[3];
consumed += 2;
wsFrame->headerLen += 2;
wsFrame->handledLen += 2;
wsFrame->state = frameState_16bitLength;
break;
case frameState_63bitLengthWait:
if (wsFrame->buffSize < 10)
{
return consumed;
}
unsigned char* recvBuff = wsFrame->buff;
// 注：标准规定64位时最高bit必须为0，这里未作处理
wsFrame->payloadLen =
((uint64_t)recvBuff[2] << (8 * 7)) +
((uint64_t)recvBuff[3] << (8 * 6)) +
((uint64_t)recvBuff[4] << (8 * 5)) +
((uint64_t)recvBuff[5] << (8 * 4)) +
((uint64_t)recvBuff[6] << (8 * 3)) +
((uint64_t)recvBuff[7] << (8 * 2)) +
((uint64_t)recvBuff[8] << (8 * 1)) +
((uint64_t)recvBuff[9] << (8 * 0));
consumed += 8;
wsFrame->headerLen += 8;
wsFrame->handledLen += 8;
wsFrame->state = frameState_63bitLength;
break;
case frameState_16bitLength:
// 2字节共有字段 + 2字节附加长度字段 + 4字节掩码
if (wsFrame->buffSize < 8)
{
return consumed;
}
for (int i = 0; i < 4; i++)
{
wsFrame->mask[i] = wsFrame->buff[i + 4];
}
consumed += 4;
wsFrame->headerLen += 4;
wsFrame->handledLen += 4;
wsFrame->state = frameState_maskingKey;
break;
case frameState_63bitLength:
// 2字节共有字段 + 8字节附加长度字段 + 4字节掩码
if (wsFrame->buffSize < 14)
{
return consumed;
}
for (int i = 0; i < 4; i++)
{
wsFrame->mask[i] = wsFrame->buff[i + 10];
}
consumed += 4;
wsFrame->headerLen += 4;
wsFrame->handledLen += 4;
wsFrame->state = frameState_maskingKey;
break;
case frameState_maskingKey:
wsFrame->state = frameState_readingData;
break;
case frameState_readingData:
; // case第一个语句不能是变量声明
uint64_t total = wsFrame->payloadLen + wsFrame->headerLen;
// 注意 buff的长度可能大于帧总长度
// 因为TCP是面向字节流的，buff中有可能包含下一帧的数据
// 所以读取时要根据帧头和载荷长度来判断最多读多少数据
if (wsFrame->buffSize >= total)
{
consumed += total - wsFrame->handledLen;
wsFrame->handledLen = total;
wsFrame->state = frameState_success;
}
else
{
consumed += wsFrame->buffSize - wsFrame->handledLen;
wsFrame->handledLen = wsFrame->buffSize;
return consumed;
}
break;
case frameState_success:
return consumed;
break;
case frameState_failure:
return consumed;
break;
}
goto stateTransitionBegin;
return consumed;
}
int wsFrameSend(SOCKET socket, const char* buff, int len, FrameType type)
{
int newLen;
const char* frame = convertToWebSocketFrame(buff, type, len, &newLen);
int iSendResult = send(socket, frame, newLen, 0);
if (iSendResult == SOCKET_ERROR)
{
printLog("wsFrameSend", 1, "Send failed: %d", WSAGetLastError());
goto wsFrameSendEnd;
}
wsFrameSendEnd:
free((void*)frame);
return iSendResult;
}
// 处理WebSocket帧数据，返回-1代表需要关闭连接
int wsClientDataHandle(const char* recvBuff, int recvLen, Client* client)
{
WsFrame* wsFrame = &client->wsFrame;
if (recvLen == 0)
{
return 0;
}
int consume = readWebSocketFrameStream(wsFrame, recvBuff, recvLen);
if (wsFrame->state == frameState_success)
{
// 暂时不处理多帧数据，遇到多帧数据关闭连接
if (wsFrame->FIN == 0)
{
return -1;
}
// 客户端希望关闭连接
if (wsFrame->frameType == frameType_connectionClose)
{
return -1;
}
// 遇到意料之外的帧类型
if (wsFrame->frameType == frameType_binary ||
wsFrame->frameType == frameType_pong ||
wsFrame->frameType == frameType_continuation
)
{
return -1;
}
uint64_t payloadLen = wsFrame->payloadLen;
u_char* payload = wsFrame->buff + wsFrame->headerLen;
// 解码载荷
for (uint64_t j = 0; j < payloadLen; j++)
{
payload[j] = payload[j] ^ wsFrame->mask[j % 4];
}
int iSendResult = 0;
// 心跳
if (wsFrame->frameType == frameType_ping)
{
wsFrameSend(client->socket, payload, payloadLen, frameType_pong);
}
// 处理文本数据
if (wsFrame->frameType == frameType_text)
{
wsClientTextDataHandle(payload, payloadLen, client->socket);
}
}
// 一个帧接收完成并处理完毕后释放内存
if (wsFrame->state == frameState_success)
{
freeWebSocketFrame(wsFrame);
}
// 解析ws帧出错，释放内存并通知关闭连接
if (wsFrame->state == frameState_failure)
{
freeWebSocketFrame(wsFrame);
return -1;
}
// 传入的数据不止包含当前帧，包含下一帧的数据
if (consume != recvLen)
{
return wsClientDataHandle(recvBuff + consume, recvLen - consume, client);
}
return 0;
}
处理文本数据的方法wsClientTextDataHandle代码
// 处理数据，也可以写在别处做回调函数
void wsClientTextDataHandle(const char* payload, uint64_t payloadLen, SOCKET socket)
{
const char* parseEnd;
cJSON* json = cJSON_ParseWithOpts(payload, &parseEnd, 0);
if (json == NULL)
{
const char* error_ptr = cJSON_GetErrorPtr();
if (error_ptr != NULL)
{
printLog("jsonParse", "Error before: %d", error_ptr - payload);
}
return;
}
const cJSON* j_msg = cJSON_GetObjectItemCaseSensitive(json, "msg");
const cJSON_bool e_msg = cJSON_IsString(j_msg);
const char* v_msg = e_msg ? j_msg->valuestring : NULL;
char* gbkText = UTF8ToGBK(v_msg);
sendJSON(socket, "send", GBKToUTF8(gbkText));
free((void*)gbkText);
}
给客户端发送消息的代码
int wsFrameSend(SOCKET socket, const char* buff, int len, FrameType type)
{
int newLen;
const char* frame = convertToWebSocketFrame(buff, type, len, &newLen);
int iSendResult = send(socket, frame, newLen, 0);
if (iSendResult == SOCKET_ERROR)
{
printLog("wsFrameSend", 1, "Send failed: %d", WSAGetLastError());
goto wsFrameSendEnd;
}
printLog("wsFrameSend","Bytes sent: %d", iSendResult);
wsFrameSendEnd:
free((void*)frame);
return iSendResult;
}
void sendJSON(SOCKET socket, const char* event, const char* data)
{
cJSON* root = cJSON_CreateObject();
cJSON_AddItemToObject(root, "event", cJSON_CreateString(event));
cJSON_AddItemToObject(root, "data", cJSON_CreateString(data));
const char* jsonStr = cJSON_PrintUnformatted(root);
wsFrameSend(socket, jsonStr, strlen(jsonStr), frameType_text);
cJSON_Delete(root);
free((void*)jsonStr);
}
到这里主要的核心代码就写完了，接下来测试一下
int main()
{
int result = serverStart("127.0.0.1", 1024, "/");
if (result != 0)
{
MessageBoxA(NULL, "wsserver start failed", "WebSocket Plugin", MB_OK | MB_ICONERROR);
}
else
{
//fileLog("websocket server startup success");
}
system("pause");
return 0;
}
测试成功 如图所示
出处：https://www.cnblogs.com/Ax0ne/p/c-language-websocket-programming.html
标签：frameState,websocket,VS2019,int,return,C语言,char,wsFrame,const From： https://www.cnblogs.com/mq0036/p/17301774.html