File content as of revision 8:6635ca3b5a5c:

#include "WebSocketServer.h"
#include "sha1.h"

WebSocketServer::WebSocketServer() {
}

WebSocketServer::~WebSocketServer() {
}

bool WebSocketServer::init(int port) {
	mTCPSocketServer.set_blocking(true);

	int ret = mTCPSocketServer.bind(port);
	if (ret != 0) {
		printf("ERROR: Failed to bind %d\r\n", ret);
		return false;
	}
	ret = mTCPSocketServer.listen();
	if (ret != 0) {
		printf("ERROR: Failed to listen %d\r\n", ret);
		return false;
	}

	return true;
}

void WebSocketServer::run() {
	// TCPSocketConnection connection;
	char buf[1024];

	while (true) {
		bool isWebSocket = false;
		printf("accepting\r\n");
		int ret = mTCPSocketServer.accept(mConnection);
		if (ret != 0) {
			continue;
		}
		printf("New connection\r\n");
		mConnection.set_blocking(true);

		while (mConnection.is_connected()) {
			ret = mConnection.receive(buf, sizeof(buf) - 1);
			if (ret == 0) {
//				printf("No data to receive\r\n");
				continue;
			}
			if (ret < 0) {
				printf("ERROR: Failed to receive %d\r\n", ret);
				break;
			}
			if (!isWebSocket) {
				if (this->handleHTTP(buf, ret)) {
					isWebSocket = true;
				} else {
					printf("ERROR: Non websocket\r\n");
					break;
				}
			} else {
				if (!this->handleWebSocket(buf, ret)) {
					printf("websocket closed\r\n");
					break;
				}
			}
		}
		printf("closed\r\n");
		mConnection.close();
	}
}

bool WebSocketServer::setHandler(const char* path, WebSocketHandler* handler) {
	mHandler = handler; // support only one handler now
	return true;
}

#define UPGRADE_WEBSOCKET	"Upgrade: websocket"
#define SEC_WEBSOCKET_KEY	"Sec-WebSocket-Key:"
#define MAGIC_NUMBER		"258EAFA5-E914-47DA-95CA-C5AB0DC85B11"

bool WebSocketServer::handleHTTP(char* buf, int size) {
	char* line = &buf[0];
	char key[128];
	bool isUpgradeWebSocket = false;
	bool isSecWebSocketKeyFound = false;

	for (int i = 0; i < size; i++) {
		if (buf[i] == '\r' && i+1 < size && buf[i+1] == '\n') {
			buf[i] = '\0';
			if (strlen(buf) <= 0) {
				break;
			}
			printf("[%s]\r\n", line);
			if (line == &buf[0]) {
				char* method = strtok(buf, " ");
				char* path = strtok(NULL, " ");
				char* version = strtok(NULL, " ");
//				printf("[%s] [%s] [%s]\r\n", method, path, version);

			} else if (strncmp(line, UPGRADE_WEBSOCKET, strlen(UPGRADE_WEBSOCKET)) == 0) {
				isUpgradeWebSocket = true;
				printf("*** %s found\r\n", UPGRADE_WEBSOCKET);
			} else if (strncmp(line, SEC_WEBSOCKET_KEY, strlen(SEC_WEBSOCKET_KEY)) == 0) {
				printf("*** %s found\r\n", SEC_WEBSOCKET_KEY);
				isSecWebSocketKeyFound = true;
				char* ptr = line + strlen(SEC_WEBSOCKET_KEY);
				while (*ptr == ' ') ++ptr;
				strcpy(key, ptr);
				printf("*** key=%s\r\n", key);
			}
			i += 2;
			line = &buf[i];
		}
	}

	if (isUpgradeWebSocket && isSecWebSocketKeyFound) {
		this->sendUpgradeResponse(key);
		mPrevFin = true;
		return true;
	}

	return false;
}

#define OP_CONT		0x0
#define OP_TEXT		0x1
#define OP_BINARY	0x2
#define OP_CLOSE	0x8
#define OP_PING		0x9
#define OP_PONG		0xA

bool WebSocketServer::handleWebSocket(char* buf, int size) {
	uint8_t* ptr = (uint8_t*)buf;

	bool fin = (*ptr & 0x80) == 0x80;
	uint8_t opcode = *ptr & 0xF;
//	printf("Byte1: %02X\r\n", *ptr);

//	printf("fin=%d\r\n", fin);
	printf("opcode=%d\r\n", opcode);

	if (opcode == OP_PING) {
		*ptr = ((*ptr & 0xF0) | OP_PONG);
		mConnection.send_all(buf, size);
		return true;
	}
	if (opcode == OP_CLOSE) {
		return false;
	}
	ptr++;
//	printf("Byte2: %02X\r\n", *ptr);

	if (!fin || !mPrevFin) {	
		printf("WARN: Data consists of multiple frame not supported\r\n");
		mPrevFin = fin;
		return true; // not an error, just discard it
	}
	mPrevFin = fin;

	bool mask = (*ptr & 0x80) == 0x80;
	uint8_t len = *ptr & 0x7F;
	ptr++;
	
//	printf("mask=%d\r\n", mask);
//	printf("length=%d\r\n", len);
	
	if (len > 125) {
		printf("WARN: Extended payload lenght not supported\r\n");
		return true; // not an error, just discard it
	}

	char* data;
	if (mask) {
		char* maskingKey = (char*)ptr;
		data = (char*)(ptr + 4);
		for (int i = 0; i < len; i++) {
        	data[i] = data[i] ^ maskingKey[(i % 4)];
        }
	} else {
		data = (char*)ptr;
	}
	if (mHandler) {
		if (opcode == OP_TEXT) {
//			printf("OP_TEXT\r\n");
			data[len] = '\0';
			mHandler->onMessage(data);
		} else if (opcode == OP_BINARY) {
//			printf("OP_BINARY %d\r\n", len);
			mHandler->onMessage(data, len);
		}
	}
//	printf("return true\r\n");
	return true;
}

static char encoding_table[] = {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
                                'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
                                'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
                                'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
                                'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
                                'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
                                'w', 'x', 'y', 'z', '0', '1', '2', '3',
                                '4', '5', '6', '7', '8', '9', '+', '/'};
static int mod_table[] = {0, 2, 1};

char *base64_encode(const unsigned char *data,
                    size_t input_length,
                    // size_t *output_length
                    char* encoded_data,
                    size_t buffer_length) {

    // *output_length = 4 * ((input_length + 2) / 3);
    size_t output_length = 4 * ((input_length + 2) / 3);
    if (buffer_length - 1 < output_length) {
    	return NULL;
    }

    // char *encoded_data = malloc(*output_length);
    // if (encoded_data == NULL) return NULL;

    for (int i = 0, j = 0; i < input_length;) {

        uint32_t octet_a = i < input_length ? (unsigned char)data[i++] : 0;
        uint32_t octet_b = i < input_length ? (unsigned char)data[i++] : 0;
        uint32_t octet_c = i < input_length ? (unsigned char)data[i++] : 0;

        uint32_t triple = (octet_a << 0x10) + (octet_b << 0x08) + octet_c;

        encoded_data[j++] = encoding_table[(triple >> 3 * 6) & 0x3F];
        encoded_data[j++] = encoding_table[(triple >> 2 * 6) & 0x3F];
        encoded_data[j++] = encoding_table[(triple >> 1 * 6) & 0x3F];
        encoded_data[j++] = encoding_table[(triple >> 0 * 6) & 0x3F];
    }

    for (int i = 0; i < mod_table[input_length % 3]; i++)
        // encoded_data[*output_length - 1 - i] = '=';
        encoded_data[output_length - 1 - i] = '=';
    encoded_data[output_length] = '\0';

    return encoded_data;
}

bool WebSocketServer::sendUpgradeResponse(char* key) {
	char buf[128];

	if (strlen(key) + sizeof(MAGIC_NUMBER) > sizeof(buf)) {
		return false;
	}
	strcpy(buf, key);
	strcat(buf, MAGIC_NUMBER);

    unsigned char hash[20];
	char encoded[30];
    sha1(buf, strlen(buf), (char*)hash);
    base64_encode(hash, 20, encoded, sizeof(encoded));

    char resp[] = "HTTP/1.1 101 Switching Protocols\r\n" \
	    "Upgrade: websocket\r\n" \
    	"Connection: Upgrade\r\n" \
    	"Sec-WebSocket-Accept: XXXXXXXXXXXXXXXXXXXXXXXXXXXXX\r\n\r\n";
    char* ptr = strstr(resp, "XXXXX");
    strcpy(ptr, encoded);
    strcpy(ptr+strlen(encoded), "\r\n\r\n");

    int ret = mConnection.send_all(resp, strlen(resp));
    if (ret < 0) {
    	printf("ERROR: Failed to send response\r\n");
    	return false;
    }

    return true;
}