121 lines
3.4 KiB
C

/*
* This file is part of the socksnippet project.
* Copyright 2022 Edward V. Emelianov <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 3 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, see <http://www.gnu.org/licenses/>.
*/
// client-side functions
#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <usefull_macros.h>
#include "client.h"
#include "socket.h"
/**
* @brief processData - process here some actions and make messages for server
* @param buf (o) - buffer for answer
* @param l - max length of buf
* @return amount of answer bytes
*/
static int process_data(char *buf, int l){
if(!buf || !l) return 0;
/* USERCODE: get here some data to send */
static double t0 = 0.;
if(dtime() - t0 > 1.){
t0 = dtime();
// send random commands each 1 second
int x = rand() % 600;
const char *cmd = NULL;
if(x < 100) cmd = "time";
else if(x < 200) cmd = "getval1";
else if(x < 300) cmd = "getval2";
else if(x < 400) cmd = "ping";
if(cmd) snprintf(buf, l, "%s", cmd);
else{
if(x < 500) snprintf(buf, l, "setval1=%d", rand() & 0xff);
else snprintf(buf, l, "setval2=%d", rand() & 0xff);
}
return strlen(buf);
}
return 0;
}
/**
* @brief process_server_message - parse messages from server and make an answer
* @param buf (io) - incoming message (the answer will be in this buffer)
* @param l - buff max length
* @return amount of answer bytes
*/
static int process_server_message(char *buf, int l){
/* USERCODE inside this funtion */
if(!buf || !l) return 0;
// just show on screen
green("SERVER send: %s\n", buf);
return 0;
}
/**
* check data from fd (polling function for client)
* @param fd - file descriptor
* @return 0 in case of timeout, 1 in case of fd have data, -1 if error
*/
static int canberead(int fd){
fd_set fds;
struct timeval timeout;
timeout.tv_sec = 0;
timeout.tv_usec = 100;
FD_ZERO(&fds);
FD_SET(fd, &fds);
do{
int rc = select(fd+1, &fds, NULL, NULL, &timeout);
if(rc < 0){
if(errno != EINTR){
LOGWARN("select()");
WARN("select()");
return -1;
}
continue;
}
break;
}while(1);
if(FD_ISSET(fd, &fds)){
//DBG("FD_ISSET");
return 1;
}
return 0;
}
void client(int sock){
char buf[BUFLEN];
while(1){
int l = process_data(buf, BUFLEN-1);
if(l) sendmessage(sock, buf, l);
if(1 != canberead(sock)) continue;
int n = read(sock, buf, BUFLEN-1);
if(n == 0){
WARNX("Server disconnected");
signals(0);
}
buf[n] = 0;
DBG("Got from server: %s", buf);
LOGMSG("Got from server: %s", buf);
l = process_server_message(buf, n);
if(l) sendmessage(sock, buf, l);
}
}