add very small websocket example

comments_before.c

@@ -0,0 +1,97 @@
+/*
+ * comments_before.c - put multiline comments before text in string they follow
+ *
+ *
+ * Copyright 2015 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#include <stdio.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct{
+	char *data;
+	size_t len;
+} mmapbuf;
+
+mmapbuf *My_mmap(char *filename){
+	int fd;
+	char *ptr;
+	size_t Mlen;
+	struct stat statbuf;
+	if(!filename) exit(-1);
+	if((fd = open(filename, O_RDONLY)) < 0) exit(-2);
+	if(fstat (fd, &statbuf) < 0) exit(-3);
+	Mlen = statbuf.st_size;
+	if((ptr = mmap (0, Mlen, PROT_READ, MAP_PRIVATE, fd, 0)) == MAP_FAILED)
+		exit(-4);
+	if(close(fd)) exit(-5);
+	mmapbuf *ret = calloc(1, sizeof(mmapbuf));
+	ret->data = ptr;
+	ret->len = Mlen;
+	return  ret;
+}
+
+
+int main(int argc, char **argv){
+	mmapbuf *buf = My_mmap(argv[1]);
+	char *afile = strdup(buf->data), *eptr = afile + buf->len;
+	char *beforecom = NULL;
+	while(afile < eptr){
+		char *nl = strchr(afile, '\n');
+		if(!nl){
+			printf("%s\n", afile);
+			return 0;
+		}
+		*nl++ = 0;
+		char *commstart = strstr(afile, "/*");
+		if(commstart){
+			*commstart = 0;
+			free(beforecom);
+			beforecom = strdup(afile);
+			commstart += 2;
+			char *commend = NULL;
+			if(*commstart) commend = strstr(commstart, "*/");
+			if(commend){ // single comment
+				*commend = 0;
+				afile = commend + 2;
+				printf("/* %s */\n", commstart);
+				printf("%s%s\n", beforecom, afile);
+				afile = nl;
+			}else{ // multiline comment
+				printf("/*%s\n", commstart);
+				commend = strstr(nl, "*/");
+				if(!commend){
+					printf("%s*/\n", nl);
+					return -1;
+				}
+				*commend = 0;
+				afile = commend + 2;
+				if(*afile == '\n') ++afile;
+				printf("%s*/\n", nl);
+			}
+		}else{
+			printf("%s\n", afile);
+			afile = nl;
+		}
+	}
+}

simple_websockets/Makefile

@@ -0,0 +1,22 @@
+PROGRAM = websocktest
+LDFLAGS = $(shell pkg-config --libs libwebsockets) -lpthread
+SRCS = main.c que.c
+CC = gcc
+DEFINES += -DEBUG
+CXX = gcc
+CFLAGS = -Werror -Wextra $(DEFINES) $(shell pkg-config --cflags libwebsockets)
+OBJS = $(SRCS:.c=.o)
+all : $(PROGRAM)
+$(PROGRAM) : $(OBJS)
+	$(CC) $(CFLAGS) $(OBJS) $(LDFLAGS) -o $(PROGRAM)
+
+# some addition dependencies
+# %.o: %.c
+#        $(CC) $(LDFLAGS) $(CFLAGS) $< -o $@
+#$(SRCS) : %.c : %.h $(INDEPENDENT_HEADERS)
+#        @touch $@
+
+clean:
+	/bin/rm -f *.o *~
+depend:
+	$(CXX) -MM $(CXX.SRCS)

simple_websockets/Readme.md

@@ -0,0 +1,3 @@
+### Websockets test
+
+

simple_websockets/dbg.h

@@ -0,0 +1,39 @@
+/*
+ * dbg.h
+ *
+ * Copyright 2016 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#pragma once
+#ifndef __DBG_H__
+#define __DBG_H__
+
+#if defined EBUG || defined DEBUG
+#ifndef DBG
+#define DBG(...) do{fprintf(stderr, __VA_ARGS__); fprintf(stderr, "\n");}while(0)
+#endif
+#else
+#define DBG(...)
+#endif
+
+
+#ifndef _U_
+	#define _U_    __attribute__((__unused__))
+#endif
+
+#endif // __DBG_H__

simple_websockets/main.c

@@ -0,0 +1,224 @@
+/*
+ * main.c
+ *
+ * Copyright 2016 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <signal.h>
+#include <libwebsockets.h>
+#include <pthread.h>
+#include <sys/prctl.h>
+#include <time.h>
+
+#include "dbg.h"
+#include "que.h"
+
+#define MESSAGE_LEN        (512)
+#define FRAME_SIZE         (LWS_SEND_BUFFER_PRE_PADDING + MESSAGE_LEN + LWS_SEND_BUFFER_POST_PADDING)
+
+
+char *client_IP = NULL; // IP of first connected client
+volatile int stop = 0;
+pthread_mutex_t command_mutex, ip_mutex;
+
+static void interrupt(_U_ int signo) {
+	stop = 1;
+}
+
+
+int ws_write(struct lws *wsi_in, char *str){
+	if (!str || !wsi_in)
+		return -1;
+	unsigned char buf[FRAME_SIZE];
+	int n;
+	size_t len = strlen(str);
+	if(len > MESSAGE_LEN) len = MESSAGE_LEN;
+	memcpy(buf + LWS_SEND_BUFFER_PRE_PADDING, str, len);
+	n = lws_write(wsi_in, buf + LWS_SEND_BUFFER_PRE_PADDING, len, LWS_WRITE_TEXT);
+	DBG("write %s\n", str);
+	return n;
+}
+
+void websig(char *command){
+	/*while(data_in_buf);
+	pthread_mutex_lock(&command_mutex);
+	strncpy(cmd_buf, command, CMDBUFLEN);
+	data_in_buf = 1;
+	pthread_mutex_unlock(&command_mutex);*/
+	DBG("get message: %s\n", command);
+}
+
+static int control_callback(struct lws *wsi,
+							enum lws_callback_reasons reason, void *user,
+							void *in, size_t len){
+	char client_name[128];
+	char client_ip[128];
+	control_data *dat = (control_data *) user;
+	char *msg = (char*) in;
+	void parse_que_msg(control_data *d){
+		char *M;
+		if((M = get_message_from_que(d))){
+			ws_write(wsi, M);
+		}
+	}
+    switch (reason) {
+		case LWS_CALLBACK_ESTABLISHED:
+			memset(dat, 0, sizeof(control_data));
+			pthread_mutex_lock(&ip_mutex);
+			lws_get_peer_addresses(wsi, lws_get_socket_fd(wsi),
+						client_name, 128, client_ip, 128);
+			if(!client_IP)
+				client_IP = strdup(client_ip);
+			else if(strcmp(client_IP, client_ip)){
+				char buf[256];
+				snprintf(buf, 255, "Already connected from %s.<br>Please, disconnect.", client_IP);
+				DBG("Already connected\n");
+				put_message_to_que(buf, dat);
+				snprintf(buf, 255, "Try of connection from %s", client_ip);
+				glob_que(buf);
+				dat->already_connected = 1;
+			}
+			pthread_mutex_unlock(&ip_mutex);
+			lws_callback_on_writable(wsi);
+		break;
+		case LWS_CALLBACK_SERVER_WRITEABLE:
+			if(dat->num)
+				parse_que_msg(dat);
+			if(!dat->already_connected && global_que.num)
+				parse_que_msg(&global_que);
+			usleep(500);
+			lws_callback_on_writable(wsi);
+			return 0;
+		break;
+		case LWS_CALLBACK_RECEIVE:
+			if(!dat->already_connected)
+				websig(msg);
+		break;
+		case LWS_CALLBACK_CLOSED:
+			DBG("closed\n");
+			if(!dat->already_connected){
+				pthread_mutex_lock(&ip_mutex);
+				free(client_IP);
+				client_IP = NULL;
+				pthread_mutex_unlock(&ip_mutex);
+			}
+		break;
+	}
+	return 0;
+}
+
+struct lws_protocols protocols[] = {
+	{
+		"IRBIS_control",			// name
+		control_callback,			// callback
+		sizeof(control_data),		// control_data_size
+		FRAME_SIZE,					// max frame size / rx buffer
+		0, NULL						// id, user
+	},
+	{ NULL, NULL, 0, 0, 0, NULL} /* terminator */
+};
+
+void *websock_thread(_U_ void *buf){
+	struct lws_context_creation_info info;
+	struct lws_context *context;
+
+	memset(&info, 0, sizeof info);
+	info.port = 9999;
+	info.iface = NULL;
+	info.protocols = protocols;
+	info.extensions = lws_get_internal_extensions();
+	info.ssl_cert_filepath = NULL;
+	info.ssl_private_key_filepath = NULL;
+	info.gid = -1;
+	info.uid = -1;
+	info.options = 0;
+
+	context = lws_create_context(&info);
+	if (context == NULL) {
+		lwsl_err("libwebsocket init failed\n");
+		stop = 1;
+	}
+	while (!stop) {
+		lws_service(context, 50);
+	}
+	usleep(10);
+	lws_context_destroy(context);
+	return NULL;
+}
+
+void *worker_thread(_U_ void* buf){
+	time_t t = time(NULL), oldt;
+	while(!stop){
+		oldt = t;
+		if(client_IP){
+			glob_que(ctime(&t));
+		}
+		while((t = time(NULL)) == oldt) usleep(1000);
+	}
+}
+
+static void main_proc(){
+	pthread_t ws_thread, wr_thread;
+	if(pthread_create(&ws_thread, NULL, websock_thread, NULL)){
+		fprintf(stderr, "Can't create websocket thread!\n");
+		stop = 1;
+		return;
+	}
+	if(pthread_create(&wr_thread, NULL, worker_thread, NULL)){
+		fprintf(stderr, "Can't create worker thread!\n");
+		stop = 1;
+		return;
+	}
+	while(!stop){
+	/*	pthread_mutex_lock(&command_mutex);
+		if(data_in_buf) process_buf(cmd_buf);
+		data_in_buf = 0;
+		pthread_mutex_unlock(&command_mutex);*/
+		usleep(1000); // give another treads some time to fill buffer
+	}
+	DBG("stop threads");
+	pthread_cancel(ws_thread);
+	pthread_cancel(wr_thread);
+	pthread_join(ws_thread, NULL);
+	pthread_join(wr_thread, NULL);
+	DBG("return main_proc");
+}
+
+int main(void) {
+	signal(SIGINT, interrupt);
+	signal(SIGTERM, interrupt);
+	signal(SIGQUIT, SIG_IGN);
+	signal(SIGTSTP, SIG_IGN);
+	while(1){
+		if(stop) return 0;
+		pid_t childpid = fork();
+		if(childpid){
+			DBG("Created child with PID %d\n", childpid);
+			wait(NULL);
+			DBG("Child %d died\n", childpid);
+		}else{
+			prctl(PR_SET_PDEATHSIG, SIGTERM); // send SIGTERM to child when parent dies
+			main_proc();
+			return 0;
+		}
+	}
+	return 0;
+}

simple_websockets/que.c

@@ -0,0 +1,47 @@
+/*
+ * que.c
+ *
+ * Copyright 2016 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+#include <string.h>
+#include "que.h"
+
+char que[MESSAGE_LEN];
+control_data global_que;
+
+void put_message_to_que(char *msg, control_data *dat){
+	int L = strlen(msg);
+	if(dat->num >= MESSAGE_QUE_SIZE) return;
+	++dat->num;
+	if(L < 1 || L > MESSAGE_LEN - 1) L = MESSAGE_LEN - 1;
+	strncpy(dat->message[dat->idxwr], msg, L);
+	dat->message[dat->idxwr][L] = 0;
+	if((++(dat->idxwr)) >= MESSAGE_QUE_SIZE) dat->idxwr = 0;
+}
+
+void glob_que(char *buf){
+	put_message_to_que(buf, &global_que);
+}
+
+char *get_message_from_que(control_data *dat){
+	char *R = dat->message[dat->idxrd];
+	if(dat->num <= 0) return NULL;
+	if((++dat->idxrd) >= MESSAGE_QUE_SIZE) dat->idxrd = 0;
+	--dat->num;
+	return R;
+}

simple_websockets/que.h

@@ -0,0 +1,44 @@
+/*
+ * que.h
+ *
+ * Copyright 2016 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+#pragma once
+#ifndef __QUE_H__
+#define __QUE_H__
+
+#define MESSAGE_LEN          (512)
+#define MESSAGE_QUE_SIZE   (16)
+
+
+typedef struct {
+	int num;
+	int idxwr;
+	int idxrd;
+	char message[MESSAGE_QUE_SIZE][MESSAGE_LEN];
+	int already_connected;
+} control_data;
+
+extern char que[];
+extern control_data global_que;
+void glob_que(char *buf);
+void put_message_to_que(char *msg, control_data *dat);
+char *get_message_from_que(control_data *dat);
+
+//#define GLOB_MESG(...)  do{snprintf(que, 512, __VA_ARGS__); glob_que();}while(0)
+#endif // __QUE_H__

simple_websockets/www/test.html

@@ -0,0 +1,86 @@
+<html>
+<head>
+	<title>Testing websockets</title>
+	<style type="text/css">
+	.content { vertical-align:top; text-align:center; background:#fffff0; padding:12px; border-radius:10px; }
+	button { display: block; width: 70px; text-align: center; }
+	.container {border: solid 1px;  border-radius:10px; padding:12px; }
+</style>
+<script>
+(function () { 'use strict';
+	var socket;
+	var connected = 0;
+	var wdTmout, faulttmout;
+	function $(nm){return document.getElementById(nm);}
+	function get_ws_url(){
+		var pcol;
+		var u = document.URL;
+		if (u.substring(0, 5) == "https") {
+			pcol = "wss://";
+			u = u.substr(8);
+		} else {
+			pcol = "ws://";
+			if (u.substring(0, 4) == "http")
+				u = u.substr(7);
+		}
+		u = u.split('/');
+		return pcol + u[0] + ":9999";
+	}
+	function TryConnect(){
+		if(connected) return;
+		//if(socket) delete socket;
+		var apprURL = get_ws_url();
+		var sockfn = null;
+		if(typeof MozWebSocket != "undefined")
+			sockfn = MozWebSocket;
+		else
+			sockfn = WebSocket;
+		socket = new sockfn(apprURL, "IRBIS_control");
+		if(!socket){
+			alert("Error: can't create websocket!\nMake sure that your browser supports websockets");
+			return;
+		}
+		try {
+			socket.onopen = function(){
+				$("connected").style.backgroundColor = "#40ff40";
+				$("connected").textContent = "Connection opened";
+				connected = 1;
+				socket.send("hello");
+			}
+			socket.onmessage = function(msg){
+				var answ =  msg.data
+				$("lastmsg").textContent = answ;
+			}
+			socket.onclose = function(){
+				$("connected").style.backgroundColor = "#ff4040";
+				$("connected").textContent = "Connection closed";
+				$("lastmsg").textContent = "";
+				connected = 0;
+				setTimeout(TryConnect, 1000);
+			}
+		} catch(exception) {
+			alert('Error' + exception);
+		}
+	}
+	function init(){
+		$("sendmsg").onclick = sendmsg;
+		TryConnect();
+	}
+	function sendmsg(){
+		if(connected) socket.send($("msgtosend").value);
+	}
+	var WStest = {};
+	WStest.init = init;
+	WStest.send = sendmsg;
+	window.WStest = WStest;
+}());
+</script>
+</head>
+<body onload="WStest.init()">
+	<div class="container" id="cont">
+	<div><input type="text" id="msgtosend" size="15"><button id="sendmsg">Send</button></div>
+	<div id="connected">No connection</div>
+	<div id="lastmsg"></div>
+	</div>
+</body>
+</html>

xor.c

@@ -0,0 +1,33 @@
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+
+void xor(char *buf, char *pattern, size_t l){
+	size_t i;
+	for(i = 0; i < l; ++i)
+		printf("%c", buf[i] ^ pattern[i]);
+}
+
+int main(int argc, char **argv){
+	if(argc != 3){
+		printf("Usage: %s <infile> <password>\n", argv[0]);
+		return -1;
+	}
+	char *key = strdup(argv[2]);
+	size_t n = 0, keylen = strlen(key);
+	char *buff = malloc(keylen);
+	int f = open(argv[1], O_RDONLY);
+	if(f < 0){
+		perror("Can't open file");
+		return f;
+	}
+	do{
+		n = read(f, buff, keylen);
+		xor(buff, key, n);
+	}while(n);
+	return 0;
+}