c++ websocket 协议分析与实现
前言
网上有很多第三方库，nopoll,uwebsockets,libwebsockets,都喜欢回调或太复杂，个人只需要在后端用，所以手动写个；
1:环境
ubuntu18
g++(支持c++11即可)
第三方库:jsoncpp,openssl
2:安装
jsoncpp 读取json 配置文件 用 自动安装 网上一堆教程
openssl 如果系统没带，需要安装下 sudo apt-get install openssl 一般是1.1版本 够用了
3：websocket server
1> 主要就用到 epoll 模式(io_uring 更好点，就是内核版本要高点)，3个进程 主进程作为监控进程 2个子进程 一个network进程 一个 logic 进程
2> 子进程间 主要通过共享内存 加socketpair 通知 交换数据
3>websocket 握手协议 先看例子
上前端代码 html
<!DOCTYPE HTML>
<html>
<head> <meta http-equiv="content-type" content="text/html" /> <meta name="author" content="https://github.com/" /> <title>websocket test</title> <script>var socket; function Connect(){ try{ socket=new WebSocket('ws://192.168.1.131:9000'); //'ws://192.168.1.131:9000'); }catch(e){ alert('error catch'+e); return; } socket.onopen = sOpen; socket.onerror = sError;socket.onmessage= sMessage;socket.onclose= sClose;} function sOpen(){alert('connect success!');}function sError(e){alert("[error] " + e);//writeObj(e);}function sMessage(msg){ if(typeof(msg) == 'object'){//let json = JSON.stringify(msg);//console.log('server says:' +json);//writeObj(msg);if(msg.data){ //msg.hasOwnProperty('data')console.log('server says'+msg.data);}else{writeObj(msg);//console.log('[1]server says'+msg.data);}}else{alert('server says:' + msg); }}function sClose(e){alert("connect closed:" + e.code);} function Send(){socket.send(document.getElementById("msg").value);} function Close(){socket.close();} function writeObj(obj){ var description = ""; for(var i in obj){ var property=obj[i]; description+=i+" = "+property+"\n"; } alert(description); }</script>
</head> <body>
<input id="msg" type="text">
<button id="connect" onclick="Connect();">Connect</button>
<button id="send" onclick="Send();">Send</button>
<button id="close" onclick="Close();">Close</button></body> </html>
在Microsoft Edge 运行结果
golang 前端代码如下
package mainimport ("fmt""golang.org/x/net/websocket""log""strings"
)var origin = "http://192.168.1.131:9000"
//var url = "ws://192.168.1.131:7077/websocket"
var url = "wss://192.168.1.131:9000/websocket"
func main() {ws, err := websocket.Dial(url, "", origin)if err != nil {log.Fatal(err)}// send text framevar message2 = "hello"websocket.Message.Send(ws, message2)fmt.Printf("Send: %s\n", message2)// receive text framevar message stringwebsocket.Message.Receive(ws, &message)fmt.Printf("Receive: %s\n", message)for true {fmt.Printf("please input string:")var inputstr stringfmt.Scan(&inputstr)if(strings.Compare(inputstr,"quit") == 0){break}else{websocket.Message.Send(ws, inputstr)fmt.Printf("Send: %s\n", inputstr)var output stringwebsocket.Message.Receive(ws, &output)fmt.Printf("Receive: %s\n", output)}}ws.Close()//关闭连接fmt.Printf("client exit\n")
}
测试结果
server 握手代码
int c_WebSocket::recv_handshake() {int n, len, ret;uint32_t pos = 0;uint16_t u16msglen = 0;const bool bssl = isSsl();if (bssl) {n = SSL_read(m_ssl, m_recv_buf + m_recv_pos, m_recv_buf_size - m_recv_pos);}else {n = recv(m_fd, m_recv_buf + m_recv_pos, m_recv_buf_size - m_recv_pos, 0);}if (n > 0) {if (m_is_closed) {m_recv_pos = 0;return true;}m_recv_pos += n;m_recv_buf[m_recv_pos] = 0;printf("recv %d handshake %s len=%d recvlen=%d", m_id, m_recv_buf,n,m_recv_pos);// goto READ;// int32_t pos = 0;for (;;) {if (m_recv_pos >= c_u16MinHandShakeSize) //消息头{// \r 0x0D \n 0xAconst int nRet = fetch_http_info((char*)m_recv_buf, m_recv_pos);if (1 == nRet) { //ok// f(strcasecmp(header, "Sec-Websocket-Protocol") == 0)// conn->accepted_protocol = value;// std::map<std::string, std::string>::iterator it1 = m_map_header.find("Sec-WebSocket-Key"); //一般固定24个字节std::map<std::string, std::string>::iterator it2 = m_map_header.find("Sec-WebSocket-Protocol");//int map_size = m_map_header.size();if (it1 != m_map_header.end()) {printf("key=%s value=%s %d \n", it1->first.c_str(), it1->second.c_str(), map_size);}else {return -1;}char acceptvalue[1024] = { 0, };uint32_t value_len = it1->second.length();memcpy(acceptvalue, it1->second.c_str(), value_len);// memcpy(accept_key, websocket_key, key_length);
#define MAGIC_KEY "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"memcpy(acceptvalue + value_len, MAGIC_KEY, 36);acceptvalue[value_len + 36] = 0;unsigned char md[SHA_DIGEST_LENGTH];SHA1((unsigned char*)acceptvalue, strlen(acceptvalue), md);std::string server_key = base64_encode(reinterpret_cast<const unsigned char*>(md), SHA_DIGEST_LENGTH);char rep_handshake[1024] = { 0, };memset(rep_handshake, 0, sizeof(rep_handshake));if (it2 != m_map_header.end()) {//子协议char szsub_protocol[512] = { 0, };std::size_t pos_t = it2->second.find(",");if (pos_t != std::string::npos && pos_t < 512) {memcpy(szsub_protocol, it2->second.c_str(), pos_t);sprintf(rep_handshake, "HTTP/1.1 101 Switching Protocols\r\nUpgrade: websocket\r\nConnection: Upgrade\r\nSec-WebSocket-Accept: %s\r\nSec-WebSocket-Protocol: %s\r\n\r\n",server_key.c_str(), szsub_protocol);}else {return -1;}}else {sprintf(rep_handshake, "HTTP/1.1 101 Switching Protocols\r\nUpgrade: websocket\r\nConnection: Upgrade\r\nSec-WebSocket-Accept: %s\r\n\r\n",server_key.c_str());}m_recv_pos = 0;set_handshake_ok(); //握手完毕send_pkg((uint8_t*)rep_handshake, strlen(rep_handshake));break;}else {printf("fetch_http_info nRet=%d \n ", nRet);return -2;}}else {break;}}//end forif (pos != 0 && m_recv_pos > 0) {memcpy(m_recv_buf, m_recv_buf + pos, m_recv_pos);}}else {if (bssl) {//EAGAIN或EWOULDBLOCK二者应该是一样的，对应的错误码是11//ret = SSL_get_error(m_ssl, n);//int ssl_error = SSL_get_verify_result(ssl);//if (SSL_ERROR_WANT_READ == ret || SSL_ERROR_WANT_WRITE == ret) return true;SSL_ERROR_NONE == ret n>0 ok other error//printf("SSL_get_error(%d %d %d)\n", n, ret, errno);//SSL_get_error(-1 1,11)//return false;int ret = ssl_check_error(m_ssl, n);printf("SSL_get_error(%d %d %d %d)\n", n, ret, errno, m_recv_pos);//SSL_get_error(-1 -1 11)if (ret == -2) {return true;}if (errno == EAGAIN || errno == EINTR) {return true;}return false;}else {if (n == 0)return false;if (errno == EAGAIN || errno == EINTR) {return true;}else {return false;}}}return true;
}int c_WebSocket::fetch_http_info(char* recv_buf, const uint32_t buf_len) {// \r 0x0D \n 0xAconst uint32_t max_len = 1024;char bufline[max_len] = { 0, };uint32_t bufpos = 0;uint8_t ustate = 0;//std::map<std::string, std::string> map_header;char szsubhead[max_len] = { 0, };for (uint32_t i = 0; i < buf_len; i++) {bufline[bufpos++] = recv_buf[i];if (bufpos >= max_len) return -1;if (recv_buf[i] == 0x0A) {bufline[bufpos] = 0;if (0 == ustate) { //GET /websocket HTTP/1.1if (ws_strncmp(bufline, "GET ", 4)) {if (bufpos < 15) {return -1;}//the get url must have a minimum size: GET / HTTP/1.1\r\n 16 (15 if only \n)//return nopoll_cmp (buffer + iterator, "HTTP/1.1\r\n") || nopoll_cmp (buffer + iterator, "HTTP/1.1\n");// char* pos1 = strstr(bufline, "HTTP/1.1\r\n");/// char* pos2 = strstr(bufline, "HTTP/1.1\n");int32_t nhttp1_1_pos = (int32_t)(bufpos - 2 - 8); //HTTP/1.1 8BYTE HTTP/1.1\r\n //H的位置if (bufline[bufpos - 2] != '\r') {nhttp1_1_pos += 1;//HTTP/1.1\n}const int32_t ucopylen = nhttp1_1_pos - 1 - 4; // -1 http前的空格 -4 是GET空格 的长度if (ucopylen > 0 && ucopylen < 128) { // /websocket 长度memcpy(szsubhead, bufline + 4, ucopylen);szsubhead[ucopylen] = 0;}else {return -3;}}else {return -1;}ustate = 1;bufpos = 0;}else {//if (buffer_size == 2 && nopoll_ncmp (buffer, "\r\n", 2))if (2 == bufpos && ws_strncmp(bufline, "\r\n", 2)) {//握手协议结尾ustate == 2;//检查最基本的握手协议// Connection: Upgrade// Host: 192.168.1.2 : 8080// Sec - WebSocket - Key : 821VqJT7EjnceB8m7mbwWA ==// Sec - WebSocket - Version : 13// Upgrade : websocket// ensure we have all minumum data std::map<std::string, std::string>::iterator it1 = m_map_header.find("Upgrade");//固定 websocketstd::map<std::string, std::string>::iterator it2 = m_map_header.find("Connection"); //固定 Upgradestd::map<std::string, std::string>::iterator it3 = m_map_header.find("Sec-WebSocket-Version");std::map<std::string, std::string>::iterator it4 = m_map_header.find("Sec-WebSocket-Key"); //一般固定24个字节const bool bcheckOrigin = false; //浏览器必须有，其他可能没有std::map<std::string, std::string>::iterator it5 = m_map_header.find("Origin"); //if (it1 != m_map_header.end() && ws_strncmp(it1->second.c_str(), "websocket", 9) &&it2 != m_map_header.end() && ws_strncmp(it2->second.c_str(), "Upgrade", 7) &&it3 != m_map_header.end() && ws_strncmp(it3->second.c_str(), "13", 2) &&it4 != m_map_header.end() && it4->second.length() > 12 &&(bcheckOrigin == (bcheckOrigin && it5 != m_map_header.end()))) { //其他字段忽略了return 1;}return -6;}else {char* pos1 = strstr(bufline, ":");if (pos1 != nullptr) {// std::string key = header.substr(0, end);// std::string value = header.substr(end + 2);int32_t key_len = pos1 - bufline;int32_t value_len = bufpos - key_len - 1 - 1;if (key_len > 1 && value_len > 1) {bufline[key_len] = 0;std::string key = bufline;if (bufline[bufpos - 1] == '\n') {bufline[bufpos - 1] = 0;// --value_len;}if (bufline[bufpos - 2] == '\r') {bufline[bufpos - 2] = 0;// --value_len;}std::string value = &bufline[key_len + 2];m_map_header[key] = value;}else {return -4;}}else {return -4;}bufpos = 0;}}}}return 0;
}
握手请求与回复
Origin: http://192.168.1.131:9000 ： 原始的协议和URL
Connection: Upgrade：表示要升级协议了
Upgrade: websocket：表示要升级到 WebSocket 协议；
Sec-WebSocket-Version: 13：表示 WebSocket 的版本。如果服务端不支持该版本，需要返回一个 Sec-WebSocket-Versionheader ，里面包含服务端支持的版本号
Sec-WebSocket-Key：与后面服务端响应首部的 Sec-WebSocket-Accept 是配套的，提供基本的防护，比如恶意的连接，或者无意的连接
服务端响应协议升级
HTTP/1.1 101 Switching Protocols
Connection:Upgrade
Upgrade: websocket
Sec-WebSocket-Accept: Oy4NRAQ13jhfONC7bP8dTKb4PTU=
HTTP/1.1 101 Switching Protocols： 状态码 101 表示协议切换
Sec-WebSocket-Accept：根据客户端请求首部的 Sec-WebSocket-Key 计算出来
将 Sec-WebSocket-Key 跟 258EAFA5-E914-47DA-95CA-C5AB0DC85B11 拼接。
通过 SHA1 计算出摘要，并转成 base64 字符串。计算公式如下：
Base64(sha1(Sec-WebSocket-Key + 258EAFA5-E914-47DA-95CA-C5AB0DC85B11))
Connection:Upgrade：表示协议升级
Upgrade: websocket：升级到 websocket 协议
4：接受数据帧
代码如下
int c_WebSocket::recv_dataframe() {int n, len,ret;// uint32_t pos = 0;uint16_t u16msglen = 0;const bool bssl = isSsl();if (isSsl()) {n = SSL_read(m_ssl, m_recv_buf + m_recv_pos, m_recv_buf_size - m_recv_pos);}else {n = recv(m_fd, m_recv_buf + m_recv_pos, m_recv_buf_size - m_recv_pos, 0);}// n = recv(m_fd, m_recv_buf + m_recv_pos, m_recv_buf_size - m_recv_pos, 0);if (n > 0) {if (m_is_closed) {m_recv_pos = 0;return true;}m_recv_pos += n;// goto READ;int32_t pos = 0;for (;;) {if (m_recv_pos >= c_u16MsgHeadSize) //消息头 2个字节{int t = parse_dataframe(m_recv_buf + pos, m_recv_pos);if (t < 0) return false;else if (0 == t) break;pos += t;m_recv_pos -= t; u16msglen + c_u16MsgHeadSize; //sub one packet len// pos += u16msglen + c_u16MsgHeadSize;}else {break;}}//end forif (pos != 0 && m_recv_pos > 0) {memcpy(m_recv_buf, m_recv_buf + pos, m_recv_pos);}if (pos > 0) { //收到消息的时间m_lastrecvmsg = get_reactor().getCurSecond();}}else {if (bssl) {//ret = SSL_get_error(m_ssl, n);//if (SSL_ERROR_WANT_READ == ret || SSL_ERROR_WANT_WRITE == ret) return true;SSL_ERROR_NONE == ret n>0 ok other error//return false;int ret = ssl_check_error(m_ssl, n);if (ret == -2) {return true;}if (errno == EAGAIN || errno == EINTR) {return true;}return false;}else {if (n == 0)return false;if (errno == EAGAIN || errno == EINTR) {return true;}else {return false;}}}return true;
}
处理数据帧，把payload 转发到 logic进程，由logic去处理
一帧数据长度超过 65k 直接抛弃，这里可以根据实际需求设定长度
int c_WebSocket::parse_dataframe(uint8_t* recv_buf, const uint32_t buf_len) {/* get fin bytes */
#define FAIL_AND_CLOSE -1 //接受失败OR 关闭
#define NEED_CLOSE -1 //需要关闭#define CONTINUE_RECV_MSG 0 //消息不完整，需要继续接受
#define ONE_MSG_LENGHT(X) X //接受完一条消息，消息总长度为X#define MASK_LEN 4 //掩码长度
#define PAYLOAD_LENGTH_126 2 //126 额外2个字节uint8_t t_fin = msg_get_bit(recv_buf[0], 7);if (t_fin == 0) return FAIL_AND_CLOSE;uint8_t t_code = recv_buf[0] & 0x0F;uint8_t t_masked = msg_get_bit(recv_buf[1], 7);uint16_t t_payload_size = recv_buf[1] & 0x7F;if (t_masked == 0) return FAIL_AND_CLOSE;if (t_code == CLOSE_FRAME) { //关闭帧return NEED_CLOSE;}uint16_t t_playload_pos = c_u16MsgHeadSize;if (t_payload_size == 126) {if (buf_len < c_u16MsgHeadSize + PAYLOAD_LENGTH_126) return CONTINUE_RECV_MSG;uint16_t length = 0;memcpy(&length, recv_buf + c_u16MsgHeadSize, PAYLOAD_LENGTH_126);if (length > MAX_PAYLOAD_REQ) return FAIL_AND_CLOSE; //消息过长if (buf_len < c_u16MsgHeadSize + PAYLOAD_LENGTH_126 + MASK_LEN + length) return CONTINUE_RECV_MSG; //等下此接受 //4 为mask长度，前端发过来必须有t_payload_size = length;t_playload_pos += PAYLOAD_LENGTH_126; //}else if (t_payload_size == 127) {return FAIL_AND_CLOSE;}else {if (buf_len < c_u16MsgHeadSize + MASK_LEN + t_payload_size) return CONTINUE_RECV_MSG; //等下此接受}memcpy(masking_key_, &recv_buf[t_playload_pos], MASK_LEN);t_playload_pos += MASK_LEN; //if (t_code == PONG_FRAME) {if (m_lastsendping > 0) {printf("time=[%u]recv PONG_FRAME \n",g_reactor.getCurSecond());m_lastsendping = 0; //ping消息回复m_sendpingcount = 0;}return ONE_MSG_LENGHT(t_playload_pos + t_payload_size;)}if (t_payload_size == 0) {if (t_code == PING_FRAME) {// nopoll_conn_send_pong(conn, nopoll_msg_get_payload_size(msg), (noPollPtr)nopoll_msg_get_payload(msg));// nopoll_msg_unref(msg);send_data((char*)&recv_buf[t_playload_pos], t_payload_size, PONG_FRAME);return t_playload_pos + t_payload_size;}return FAIL_AND_CLOSE;}// char* play_load = (char*)&recv_buf[t_playload_pos];m_payload_length_ = t_payload_size;int j = 0;for (uint i = 0; i < m_payload_length_; i++) {j = i % 4;m_payload_[i] = recv_buf[t_playload_pos + i] ^ masking_key_[j];}//put to public procshm_block_t sb;sb.fd = m_fd;sb.id = m_id;sb.len = t_payload_size;sb.type = PROTO_BLOCK;sb.frametype = t_code;//把数据发送出去// recv_push(m_u32channel, m_u32pipeindex, &sb, m_recv_buf + pos + c_u16MsgHeadSize, false);recv_push(m_u32channel, m_u32pipeindex, &sb, (uint8_t*)m_payload_, false);//int32_t nRet = printf("client recv one complete pack len=%d m_u32pipeindex=%d nRet=%d\n", u16msglen, m_u32pipeindex, nRet);// m_recv_pos -= u16msglen + c_u16MsgHeadSize; //sub one packet len// pos += u16msglen + c_u16MsgHeadSize;return t_playload_pos + t_payload_size;}
再来个logic 进程处理
void c_Logic::dologic(struct shm_block_t* pblock, uint8_t *buf, bool brecv)
{//处理收到的逻辑switch (pblock->type){case CLOSE_BLOCK:{}break;case PROTO_BLOCK:{if (strncmp((char*)buf, "hello", 5) == 0) {buf[0] = 'H';buf[1] = 'E';buf[2] = 'L';buf[3] = 'L';buf[4] = 'O';send_data(pblock,buf,pblock->len, (WebSocketFrameType)pblock->frametype);}else {buf[0] = '_';send_data(pblock, buf, pblock->len, (WebSocketFrameType)pblock->frametype);}}break;case CDUMP_BLOCK:{}break;default:break;}
}发送数据
int send_data(struct shm_block_t* pblock, uint8_t* msg, const uint32_t msglen, WebSocketFrameType ftype) {const uint32_t MAX_PAYLOAD_SEND = 4 * 1024; //最大发送长度if (msglen > MAX_PAYLOAD_SEND) return -1;uint32_t length = msglen;char header[14];int header_size;memset(header, 0, sizeof(header));const bool bhas_fin = true;if (bhas_fin) {msg_set_bit(header, 7);}if (ftype >= 0) {header[0] |= ftype & 0x0f;}const bool bhas_mask = false; //服务器发送不需要mask,前端给过来才需要if (bhas_mask) {msg_set_bit(header + 1, 7);}header_size = 2;if (length < 126) {header[1] |= length;}else if (length <= 0xFFFF) {/* set the next header length is at least 65535 */header[1] |= 126;header_size += 2;/* set length into the next bytes */msg_set_16bit(length, header + 2);}else {//再大的不让发送 //先写上，用不上也没关系header[1] = 127;
#if defined(WS_64BIT_PLATFORM)if (length < 0x8000000000000000) {header[2] = (length & 0xFF00000000000000) >> 56;header[3] = (length & 0x00FF000000000000) >> 48;header[4] = (length & 0x0000FF0000000000) >> 40;header[5] = (length & 0x000000FF00000000) >> 32;}
#else// (length < 0x80000000)header[2] = header[3] = header[4] = header[5] = 0;
#endifheader[6] = (length & 0x00000000FF000000) >> 24;header[7] = (length & 0x0000000000FF0000) >> 16;header[8] = (length & 0x000000000000FF00) >> 8;header[9] = (length & 0x00000000000000FF);header_size += 8;}if (bhas_mask) {//不写了 //// msg_set_32bit(mask_value, header + header_size);// header_size += 4;}uint8_t buf[MAX_PAYLOAD_SEND + 14];memcpy(buf, header, header_size);memcpy(buf + header_size, msg, msglen);//send_pkg(buf, msglen + header_size);//return msglen + header_size;shm_block_t sb;sb.fd = pblock->fd;sb.id = pblock->id;sb.type = PROTO_BLOCK;sb.len = msglen + header_size;sb.frametype = (uint8_t)ftype;send_push(0, 1, &sb, buf, true);return 0;
}
5：支持 SSL
先加载证书
bool c_Accept::loadssl(const char* private_key_file, const char* server_crt_file, const char* ca_crt_file) {m_ctx = SSL_CTX_new(SSLv23_server_method());if (!m_ctx) { return false; }//assert(ctx);// 不校验客户端证书SSL_CTX_set_verify(m_ctx, SSL_VERIFY_NONE, nullptr);// 加载CA的证书 if (!SSL_CTX_load_verify_locations(m_ctx, ca_crt_file, nullptr)) {printf("SSL_CTX_load_verify_locations error!\n");return false;}// 加载自己的证书 if (SSL_CTX_use_certificate_file(m_ctx, server_crt_file, SSL_FILETYPE_PEM) <= 0) {printf("SSL_CTX_use_certificate_file error!\n");return false;}// 加载私钥if (SSL_CTX_use_PrivateKey_file(m_ctx, private_key_file, SSL_FILETYPE_PEM) <= 0) {printf("SSL_CTX_use_PrivateKey_file error!\n");return false;}// 判定私钥是否正确 if (!SSL_CTX_check_private_key(m_ctx)) {printf("SSL_CTX_check_private_key error!\n");return false;}return true;}
accept 后， ssl = SSL_new(get_ssl_ctx()); 再调用 SSL_accept
bool c_Accept::handle_input()
{sockaddr_in ip;socklen_t len;int cli_fd;while (1) {len = sizeof(ip);cli_fd = accept(m_fd, (sockaddr *)&ip, &len);if (cli_fd >= 0) {if ((uint32_t)cli_fd >= get_reactor().max_handler()) {close(cli_fd);continue;}if (!get_reactor().add_cur_connect(get_max_connect())) {printf("client max connect is over \n");close(cli_fd);return true;}SSL* ssl = nullptr;if (isSsl()) {ssl = SSL_new(get_ssl_ctx());if (ssl == nullptr) {get_reactor().sub_cur_connect();close(cli_fd);continue;}printf("accept SSL_new \n");}c_WebSocket*ts = new (std::nothrow) c_WebSocket();if (!ts) {get_reactor().sub_cur_connect();close(cli_fd);continue;}printf("accept client connect \n");ts->start(cli_fd, ip,m_u32channel,m_u32pipeindex,ssl);}else {if (errno == EAGAIN || errno == EINTR || errno == EMFILE || errno == ENFILE) {return true;}else {return false;}}}
}
void c_WebSocket::start(int fd, sockaddr_in& ip, uint32_t channel, uint32_t u32pipeindex,SSL* ssl)
{m_u32channel = channel;m_u32pipeindex = u32pipeindex;m_fd = fd;m_ip = ip;//---------------------------------------------m_lastrecvmsg = g_reactor.getCurSecond();c_heartbeat::GetInstance().handle_input_modify(fd, m_id, m_lastrecvmsg, m_lastrecvmsg);set_noblock(m_fd);m_ssl = ssl;if (isSsl()) {printf("ssl client handshake ready\n");SSL_set_fd(ssl, m_fd);int code, ret;int retryTimes = 0;// uint64_t begin = 0;//Time::SystemTime();// 防止客户端连接了但不进行ssl握手, 单纯的增大循环次数无法解决问题，while ((code = SSL_accept(ssl)) <= 0 && retryTimes++ < 100) {ret = SSL_get_error(ssl, code);if (ret != SSL_ERROR_WANT_READ) {printf("ssl accept error. sslerror=%d errno=%d \n", ret,errno); // SSL_get_error(ssl, code));break;}usleep(20 * 1000);//20ms //msleep(1); //这里最多会有2s的等待时间,以后一定要异步}if (code != 1) {handle_fini();return;}printf("ssl client handshake ok (%d)\n", retryTimes);}m_recv_buf_size = default_recv_buff_len;m_recv_buf = (uint8_t*)malloc(m_recv_buf_size);if (!m_recv_buf) {handle_fini();return;}//----------------------------------return;
}
6:心跳检查 10秒（可以自行设定）未收到消息，发送ping，发送2次，没回应 断线
bool c_WebSocket::checcklastmsg(uint32_t t) {if (m_lastrecvmsg + 10 <= t) {if (!is_handshake_ok()) return true;if (m_lastsendping > 0 && m_lastsendping + 10 <= t && m_sendpingcount > 1) {//disconnectprintf("[%u]ready disconnect \n",t);return true;}else if(m_lastsendping == 0 || (m_sendpingcount > 0 && m_lastsendping+10 <=t)){//发送pingm_lastsendping = t;++m_sendpingcount;send_ping_frame();printf("time=%u,%d send ping frame\n", t, m_sendpingcount);}}return false;
}int c_WebSocket::send_ping_frame() {uint32_t length = 0;char header[14];int header_size;memset(header, 0, sizeof(header));const bool bhas_fin = true;if (bhas_fin) {msg_set_bit(header, 7);}header[0] |= PING_FRAME & 0x0f;const bool bhas_mask = false; //服务器发送不需要mask,前端给过来才需要if (bhas_mask) {msg_set_bit(header + 1, 7);}header_size = 2;if (length < 126) {header[1] |= length;}uint8_t buf[MAX_PAYLOAD_SEND + 14];memcpy(buf, header, header_size);// memcpy(buf + header_size, msg, msglen);send_pkg(buf, header_size);return header_size;
}
void c_WebSocket::send_pkg(uint8_t* buf, uint32_t len){
//--------------------------------------------------------------
//有上次预留的uint32_t p = 0;int n;if (isSsl()) {n = SSL_write(m_ssl, buf, len); // 发送响应主体}else {n = send(m_fd, buf, len, 0);}if (n > 0) {if ((uint32_t)n == len) {//printf("send data len = %d need send len=%d \n",n,len);return;}else {p = n;}}else {if (errno != EAGAIN && errno != EINTR) {handle_error();return;}}//没发送完，存起来下次再发送，这里自行处理//----------------------------------------------------------------
}
7：json配置文件读取 jsoncpp API
bool c_JsonReader::read_json_file(const char* jsonfile)
{
#define LISTENIP "listenip"
#define LISTENPORT "listenport"
#define USESSL "usessl"
#define PRIVATEKEYFILE "privatekeyfile"
#define SERVERCRTFILE "servercrtfile"
#define CACRTFILE "cacrtfile"
#define AES128KEYHANDSHAKE "aes128keyhandshake"
#define AES128IV "aes128iv"
#define MAXCONN "maxconn"
#define CHECKHEARTBEAT "checkheartbeat"
#define OPENBLACKWHITEIP "openblackwhiteip"
#define SINGLEIPMAXCONN "singleipmaxconn"#define MIN(A,B) A<B?A:BFILE* f = fopen(jsonfile, "rb");if (f) {const int buf_size = 4 * 1024; char buf[buf_size] = { 0, };memset(buf, 0, sizeof(buf));size_t n = fread(buf, sizeof(char), buf_size, f);fclose(f);if (n < 10) {printf("read_json_file file length too short \n");return false;}Json::Reader reader;Json::Value root;if (reader.parse(buf,root)) {if (root[LISTENIP].empty() || root[LISTENPORT].empty() || root[MAXCONN].empty() \|| root[USESSL].empty() || root[AES128KEYHANDSHAKE].empty() || root[AES128IV].empty()) {printf("read_json_file base fail\n");return false;}const bool busessl = root[USESSL].asBool();m_chatSerCfg.buseSsl = busessl;if (busessl) { const bool bp = root[PRIVATEKEYFILE].empty();const bool bs = root[SERVERCRTFILE].empty();const bool bc = root[CACRTFILE].empty();if (bp || bs || bc) {printf("read_json_file ssl fail\n");return false;}strncpy(m_chatSerCfg.szprivatekeyfile, root[PRIVATEKEYFILE].asString().c_str(), MIN(root[PRIVATEKEYFILE].asString().length(), ssl_file_len));strncpy(m_chatSerCfg.szservercrtfile, root[SERVERCRTFILE].asString().c_str(), MIN(root[SERVERCRTFILE].asString().length(), ssl_file_len));strncpy(m_chatSerCfg.szcacrtfile, root[CACRTFILE].asString().c_str(), MIN(root[CACRTFILE].asString().length(), ssl_file_len));}else{}m_chatSerCfg.u16maxconn = (uint16_t)root[MAXCONN].asUInt();strncpy(m_chatSerCfg.szlistenip, root[LISTENIP].asString().c_str(), sizeof(m_chatSerCfg.szlistenip) - 1);m_chatSerCfg.nlistenport = (int32_t)root[LISTENPORT].asInt();memcpy(m_chatSerCfg.u8AES128keyhandshake, root[AES128KEYHANDSHAKE].asString().c_str(), root[AES128KEYHANDSHAKE].asString().length());memcpy(m_chatSerCfg.u8AES128iv, root[AES128IV].asString().c_str(), 16);{//safe configconst bool bcheck = root[CHECKHEARTBEAT].empty();const bool bbwip = root[OPENBLACKWHITEIP].empty();const bool bmaxconn = root[SINGLEIPMAXCONN].empty();if (!bcheck) {m_chatSerCfg.bcheckheartbeat = root[CHECKHEARTBEAT].asBool();}if (bbwip && (bbwip == bmaxconn)) {m_chatSerCfg.u8openblackwhiteip =(uint8_t) root[CHECKHEARTBEAT].asUInt();m_chatSerCfg.u8singleipmaxconn = (uint8_t)root[SINGLEIPMAXCONN].asUInt();}}return true;}}printf("json file no exist or parse json file fail \n");return false;
}
8：只是帮助分析websocket 协议
红框这边 ssl_accept 是需要优化的，可以考虑用coroutine 或 thread callback
9: 后续继续优化，差不多，再上demo
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