teotcp.c

Teonet TCP Client / Server example

Simple TCP echo server and client connected to it.

Created on July 24, 2015, 2:23 PM

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "ev_mgr.h"

#define TTCP_VERSION "0.0.1"    
#define SERVER_PORT 9050
    
void tcp_server_receive_cb(struct ev_loop *loop, ev_io *w, int revents) {
    
    #define BUF_LEN 1024
    char buffer[BUF_LEN];
    int close_flg = 0;
    
    // Read data
    int read_len = read(w->fd, buffer, BUF_LEN-1);
    buffer[read_len] = 0;
    
    //Show message
    printf("Server received %d bytes data: %s\n", read_len, buffer); 
    
    // Process received data
    if(read_len > 0) {
        
        // Create temporary buffer
        char *d = strdup(buffer); // Copy buffer
        d[strcspn(d, "\r\n")] = 0; // Remove trailing CRLF

        // Help client command
        if(!strcmp(d,"help") || !strcmp(d,"?")) {    
            
            char *b = "TCP Client commands:\n"
                      "close -- close this client\n"
                      "close_all -- close all clients of this TCP server\n"
                      "destroy -- destroy this TCP server\n";
            if(write(w->fd, b, strlen(b)) == -1); // \todo check write error
        }
        
        // Check close client command
        else if(!strcmp(d,"close")) {
            printf("The connection to client %d was closed\n", w->fd);
            close_flg = 1;
        }
        
        // Check destroy server command
        else if(!strcmp(d,"destroy")) {            
            printf("The TCP server %d was destroyed\n", w->fd);
            ksnTcpServerStopAll(((ksnetEvMgrClass *)w->data)->kt);
        }

        // Check destroy server command
        else if(!strcmp(d,"close_all")) {            
            int fd = ksnTcpGetServer(((ksnetEvMgrClass *)w->data)->kt, w->fd);
            if(fd) {
                printf("Close all TCP server %d clients\n", fd);            
                ksnTcpServerStopAllClients(((ksnetEvMgrClass *)w->data)->kt, fd);
            }
            else {
                printf("Can't find server of %d client\n", w->fd);
            }
        }

        // Send the data back to client
        else {
            if(write(w->fd, buffer, read_len) == -1); // \todo check write error
        }
        
        // Free temporary buffer
        free(d);
    }
    
    // Client has disconnected - stop this watcher
    else {        
        printf("The client %d has disconnected\n", w->fd);
        close_flg = 1;
    }
    
    // Close connection and free watcher
    if(close_flg) {        
        ksnTcpCbStop(loop, w, 1, 1);
    }
}

void tcp_server_accept_cb(struct ev_loop *loop, ev_ksnet_io *w,
                       int revents, int fd) {
    
    printf("Client %d connected\n", fd);
    
    // Connect clients fd to event manager
    ksnTcpCb(((ksnetEvMgrClass *)w->io.data)->ev_loop, w, fd, 
            tcp_server_receive_cb, w->io.data);
}

void event_cb(ksnetEvMgrClass *ke, ksnetEvMgrEvents event, void *data,
              size_t data_len, void *user_data) {
    
    switch(event) {
        
        // Calls immediately after event manager starts
        case EV_K_STARTED:
        {
            // Type of application (client or server)
            printf("Type of application: %s\n",  ke->teo_cfg.app_argv[1]); 
            
            // Server
            if(!strcmp(ke->teo_cfg.app_argv[1], "server")) {
                
                // Start TCP server
                int port_created;
                ksnTcpServerCreate(ke->kt, SERVER_PORT, 
                        tcp_server_accept_cb, NULL, &port_created);
            }
            
            //Client
            else if(!strcmp(ke->teo_cfg.app_argv[1], "client")) {
                printf("Client mode example is under construction yet,\n"
                       "trying system telnet application ...\n"); 
                char *buffer = ksnet_formatMessage("telnet 0 %d", SERVER_PORT);
                if(system(buffer) == -1); // \todo check system call error
                free(buffer);
                ksnetEvMgrStop(ke);
            }
        }
        break;
            
        // Undefined event (an error)
        default:
            break;
    }
}

int main(int argc, char** argv) {

    printf("Teotcp example ver " TTCP_VERSION ", based on teonet ver. " VERSION "\n");
    
    // Application parameters
    const char *app_argv[] = { "", "app_type"}; 
    ksnetEvMgrAppParam app_param;
    app_param.app_argc = 2;
    app_param.app_argv = app_argv;
    app_param.app_descr = NULL;
    
    // Initialize teonet event manager and Read configuration
    ksnetEvMgrClass *ke = ksnetEvMgrInitPort(argc, argv, event_cb,
            READ_OPTIONS|READ_CONFIGURATION|APP_PARAM, 0, &app_param);
    
    // Start teonet
    ksnetEvMgrRun(ke);

    return (EXIT_SUCCESS);
}