/*********************************************************************************
 *      Copyright:  (C) 2018 LingYun IoT Studio
 *                  All rights reserved.
 *
 *       Filename:  socket_server.c
 *    Description:  This file is socket server sample source code, it will echo back
 *                  the receive data from client.
 *                 
 *        Version:  1.0.0(10/23/2018)
 *         Author:  Guo Wenxue <guowenxue@gmail.com>
 *      ChangeLog:  1, Release initial version on "2017-10-23 01:41:05 PM"
 *                 
 ********************************************************************************/

#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>

#define SOCKET_PATH    "/tmp/socket.domain"

int main(int argc, char **argv)
{
    int                     rv = -1;
    int                     listen_fd,  client_fd = -1;
    struct sockaddr_un      serv_addr;             
    struct sockaddr_un      cli_addr;
    socklen_t               cliaddr_len;
    char                    buf[1024]; 
    
    //listen_fd = socket(AF_UNIX, SOCK_STREAM, 0);
    listen_fd = socket(AF_LOCAL, SOCK_STREAM, 0);
    if(listen_fd < 0 )
    {
        printf("create socket failure: %s\n", strerror(errno));
        return -1;
    }
    printf("socket create fd[%d]\n", listen_fd);


    if( !access(SOCKET_PATH, F_OK) )
    {
	unlink(SOCKET_PATH);
    }

    memset(&serv_addr, 0, sizeof(serv_addr));
    serv_addr.sun_family=AF_UNIX;
    strncpy(serv_addr.sun_path, SOCKET_PATH, sizeof(serv_addr.sun_path)-1);

    if( bind(listen_fd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0 )
    {
        printf("create socket failure: %s\n", strerror(errno));
	unlink(SOCKET_PATH);
        return -2;
    }
    printf("socket[%d] bind on path \"%s\" ok\n", listen_fd, SOCKET_PATH);

    listen(listen_fd, 13); 
    
    while(1)   
    {
        printf("\nStart waiting and accept new client connect...\n", listen_fd);
        client_fd = accept(listen_fd, (struct sockaddr*)&cli_addr, &cliaddr_len);
        if(client_fd < 0)
        {
            printf("accept new socket failure: %s\n", strerror(errno));
            return -2;
        }

        memset(buf, 0, sizeof(buf));        
        if( (rv=read(client_fd, buf, sizeof(buf))) < 0)
	{
		printf("Read data from client socket[%d] failure: %s\n", client_fd, strerror(errno));
		close(client_fd);
		continue;
	}
	else if( rv == 0 )
	{
		printf("client socket[%d] disconnected\n", client_fd);
		close(client_fd);
		continue;
	}
	printf("read %d bytes data from client[%d] and echo it back: '%s'\n", rv, client_fd, buf);

	if( write(client_fd, buf, rv) < 0 )
	{
	       	printf("Write %d bytes data back to client[%d] failure: %s\n", rv, client_fd, strerror(errno));
		close(client_fd);
	}
	
        sleep(1);
        close(client_fd); 
    } 

    close(listen_fd);
}