Simple websocket client
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Websocket.cpp
00001 #include "Websocket.h" 00002 00003 #define MAX_TRY_WRITE 20 00004 #define MAX_TRY_READ 10 00005 00006 //Debug is disabled by default 00007 #if 1 00008 #define DBG(x, ...) std::printf("[WebSocket : DBG]"x"\r\n", ##__VA_ARGS__); 00009 #define WARN(x, ...) std::printf("[WebSocket : WARN]"x"\r\n", ##__VA_ARGS__); 00010 #define ERR(x, ...) std::printf("[WebSocket : ERR]"x"\r\n", ##__VA_ARGS__); 00011 #else 00012 #define DBG(x, ...) 00013 #define WARN(x, ...) 00014 #define ERR(x, ...) 00015 #endif 00016 00017 #define INFO(x, ...) printf("[WebSocket : INFO]"x"\r\n", ##__VA_ARGS__); 00018 00019 Websocket::Websocket(char * url) { 00020 fillFields(url); 00021 socket.set_blocking(false, 400); 00022 } 00023 00024 void Websocket::fillFields(char * url) { 00025 int ret = parseURL(url, scheme, sizeof(scheme), host, sizeof(host), &port, path, sizeof(path)); 00026 if(ret) 00027 { 00028 ERR("URL parsing failed; please use: \"ws://ip-or-domain[:port]/path\""); 00029 return; 00030 } 00031 00032 if(port == 0) //TODO do handle WSS->443 00033 { 00034 port = 80; 00035 } 00036 00037 if(strcmp(scheme, "ws")) 00038 { 00039 ERR("Wrong scheme, please use \"ws\" instead"); 00040 } 00041 } 00042 00043 int Websocket::parseURL(const char* url, char* scheme, size_t maxSchemeLen, char* host, size_t maxHostLen, uint16_t* port, char* path, size_t maxPathLen) //Parse URL 00044 { 00045 char* schemePtr = (char*) url; 00046 char* hostPtr = (char*) strstr(url, "://"); 00047 if(hostPtr == NULL) 00048 { 00049 WARN("Could not find host"); 00050 return -1; //URL is invalid 00051 } 00052 00053 if( maxSchemeLen < hostPtr - schemePtr + 1 ) //including NULL-terminating char 00054 { 00055 WARN("Scheme str is too small (%d >= %d)", maxSchemeLen, hostPtr - schemePtr + 1); 00056 return -1; 00057 } 00058 memcpy(scheme, schemePtr, hostPtr - schemePtr); 00059 scheme[hostPtr - schemePtr] = '\0'; 00060 00061 hostPtr+=3; 00062 00063 size_t hostLen = 0; 00064 00065 char* portPtr = strchr(hostPtr, ':'); 00066 if( portPtr != NULL ) 00067 { 00068 hostLen = portPtr - hostPtr; 00069 portPtr++; 00070 if( sscanf(portPtr, "%hu", port) != 1) 00071 { 00072 WARN("Could not find port"); 00073 return -1; 00074 } 00075 } 00076 else 00077 { 00078 *port=0; 00079 } 00080 char* pathPtr = strchr(hostPtr, '/'); 00081 if( hostLen == 0 ) 00082 { 00083 hostLen = pathPtr - hostPtr; 00084 } 00085 00086 if( maxHostLen < hostLen + 1 ) //including NULL-terminating char 00087 { 00088 WARN("Host str is too small (%d >= %d)", maxHostLen, hostLen + 1); 00089 return -1; 00090 } 00091 memcpy(host, hostPtr, hostLen); 00092 host[hostLen] = '\0'; 00093 00094 size_t pathLen; 00095 char* fragmentPtr = strchr(hostPtr, '#'); 00096 if(fragmentPtr != NULL) 00097 { 00098 pathLen = fragmentPtr - pathPtr; 00099 } 00100 else 00101 { 00102 pathLen = strlen(pathPtr); 00103 } 00104 00105 if( maxPathLen < pathLen + 1 ) //including NULL-terminating char 00106 { 00107 WARN("Path str is too small (%d >= %d)", maxPathLen, pathLen + 1); 00108 return -1; 00109 } 00110 memcpy(path, pathPtr, pathLen); 00111 path[pathLen] = '\0'; 00112 00113 return 0; 00114 } 00115 00116 00117 bool Websocket::connect() { 00118 char cmd[200]; 00119 00120 while (socket.connect(host, port) < 0) { 00121 ERR("Unable to connect to (%s) on port (%d)", host, port); 00122 wait(0.2); 00123 return false; 00124 } 00125 00126 // sent http header to upgrade to the ws protocol 00127 sprintf(cmd, "GET %s HTTP/1.1\r\n", path); 00128 write(cmd, strlen(cmd)); 00129 00130 sprintf(cmd, "Host: %s:%d\r\n", host, port); 00131 write(cmd, strlen(cmd)); 00132 00133 sprintf(cmd, "Upgrade: WebSocket\r\n"); 00134 write(cmd, strlen(cmd)); 00135 00136 sprintf(cmd, "Connection: Upgrade\r\n"); 00137 write(cmd, strlen(cmd)); 00138 00139 sprintf(cmd, "Sec-WebSocket-Key: L159VM0TWUzyDxwJEIEzjw==\r\n"); 00140 write(cmd, strlen(cmd)); 00141 00142 sprintf(cmd, "Sec-WebSocket-Version: 13\r\n\r\n"); 00143 int ret = write(cmd, strlen(cmd)); 00144 if (ret != strlen(cmd)) { 00145 close(); 00146 ERR("Could not send request"); 00147 return false; 00148 } 00149 00150 ret = read(cmd, 200, 100); 00151 if (ret < 0) { 00152 close(); 00153 ERR("Could not receive answer\r\n"); 00154 return false; 00155 } 00156 00157 cmd[ret] = '\0'; 00158 DBG("recv: %s\r\n", cmd); 00159 00160 if ( strstr(cmd, "DdLWT/1JcX+nQFHebYP+rqEx5xI=") == NULL ) { 00161 ERR("Wrong answer from server, got \"%s\" instead\r\n", cmd); 00162 do { 00163 ret = read(cmd, 200, 100); 00164 if (ret < 0) { 00165 ERR("Could not receive answer\r\n"); 00166 return false; 00167 } 00168 cmd[ret] = '\0'; 00169 printf("%s",cmd); 00170 } while (ret > 0); 00171 close(); 00172 return false; 00173 } 00174 00175 INFO("\r\nhost: %s\r\npath: %s\r\nport: %d\r\n\r\n", host, path, port); 00176 return true; 00177 } 00178 00179 int Websocket::sendLength(uint32_t len, char * msg) { 00180 00181 if (len < 126) { 00182 msg[0] = len | (1<<7); 00183 return 1; 00184 } else if (len < 65535) { 00185 msg[0] = 126 | (1<<7); 00186 msg[1] = (len >> 8) & 0xff; 00187 msg[2] = len & 0xff; 00188 return 3; 00189 } else { 00190 msg[0] = 127 | (1<<7); 00191 for (int i = 0; i < 8; i++) { 00192 msg[i+1] = (len >> i*8) & 0xff; 00193 } 00194 return 9; 00195 } 00196 } 00197 00198 int Websocket::readChar(char * pC, bool block) { 00199 return read(pC, 1, 1); 00200 } 00201 00202 int Websocket::sendOpcode(uint8_t opcode, char * msg) { 00203 msg[0] = 0x80 | (opcode & 0x0f); 00204 return 1; 00205 } 00206 00207 int Websocket::sendMask(char * msg) { 00208 for (int i = 0; i < 4; i++) { 00209 msg[i] = 0; 00210 } 00211 return 4; 00212 } 00213 00214 int Websocket::send(char * str) { 00215 char msg[strlen(str) + 15]; 00216 int idx = 0; 00217 idx = sendOpcode(0x01, msg); 00218 idx += sendLength(strlen(str), msg + idx); 00219 idx += sendMask(msg + idx); 00220 memcpy(msg+idx, str, strlen(str)); 00221 int res = write(msg, idx + strlen(str)); 00222 return res; 00223 } 00224 00225 00226 bool Websocket::read(char * message) { 00227 int i = 0; 00228 uint32_t len_msg; 00229 char opcode = 0; 00230 char c; 00231 char mask[4] = {0, 0, 0, 0}; 00232 bool is_masked = false; 00233 Timer tmr; 00234 //DBG("START READ") 00235 // read the opcode 00236 tmr.start(); 00237 while (true) { 00238 if (tmr.read() > 3) { 00239 DBG("timeout ws\r\n"); 00240 return false; 00241 } 00242 00243 if(!socket.is_connected()) 00244 { 00245 WARN("Connection was closed by server"); 00246 return false; 00247 } 00248 00249 socket.set_blocking(false, 1); 00250 if (socket.receive(&opcode, 1) != 1) { 00251 socket.set_blocking(false, 2000); 00252 DBG("bad opcode?: 0x%X\r\n", opcode); 00253 return false; 00254 } 00255 00256 socket.set_blocking(false, 2000); 00257 00258 if (opcode == 0x81) 00259 break; 00260 } 00261 DBG("opcode: 0x%X\r\n", opcode); 00262 00263 readChar(&c); 00264 len_msg = c & 0x7f; 00265 is_masked = c & 0x80; 00266 if (len_msg == 126) { 00267 readChar(&c); 00268 len_msg = c << 8; 00269 readChar(&c); 00270 len_msg += c; 00271 } else if (len_msg == 127) { 00272 len_msg = 0; 00273 for (int i = 0; i < 8; i++) { 00274 readChar(&c); 00275 len_msg += (c << (7-i)*8); 00276 } 00277 } 00278 00279 if (len_msg == 0) { 00280 return false; 00281 } 00282 DBG("length: %d\r\n", len_msg); 00283 00284 if (is_masked) { 00285 for (i = 0; i < 4; i++) 00286 readChar(&c); 00287 mask[i] = c; 00288 } 00289 00290 int nb = read(message, len_msg, len_msg); 00291 if (nb != len_msg) 00292 return false; 00293 00294 for (i = 0; i < len_msg; i++) { 00295 message[i] = message[i] ^ mask[i % 4]; 00296 } 00297 00298 message[len_msg] = '\0'; 00299 00300 return true; 00301 } 00302 00303 bool Websocket::close() { 00304 if (!is_connected()) 00305 return false; 00306 00307 int ret = socket.close(); 00308 if (ret < 0) { 00309 ERR("Could not disconnect"); 00310 return false; 00311 } 00312 return true; 00313 } 00314 00315 bool Websocket::is_connected() { 00316 return socket.is_connected(); 00317 } 00318 00319 char* Websocket::getPath() { 00320 return path; 00321 } 00322 00323 int Websocket::write(char * str, int len) { 00324 int res = 0, idx = 0; 00325 00326 for (int j = 0; j < MAX_TRY_WRITE; j++) { 00327 00328 if(!socket.is_connected()) 00329 { 00330 WARN("Connection was closed by server"); 00331 break; 00332 } 00333 00334 if ((res = socket.send_all(str + idx, len - idx)) == -1) 00335 continue; 00336 00337 idx += res; 00338 00339 if (idx == len) 00340 return len; 00341 } 00342 00343 return (idx == 0) ? -1 : idx; 00344 } 00345 00346 int Websocket::read(char * str, int len, int min_len) { 00347 int res = 0, idx = 0; 00348 00349 for (int j = 0; j < MAX_TRY_WRITE; j++) { 00350 00351 if ((res = socket.receive_all(str + idx, len - idx)) == -1) 00352 continue; 00353 00354 idx += res; 00355 00356 if (idx == len || (min_len != -1 && idx > min_len)) 00357 return idx; 00358 } 00359 00360 return (idx == 0) ? -1 : idx; 00361 }
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