A dumb program to interpret the serial protocol for my Simplex fire panel

Simplex.cpp

/*
 * Main.cpp
 *
 *  Created on: 9-Jan-2009
 *      Author: root
 */


/////////////////////////////////////////////////
// Serial port interface program               //
/////////////////////////////////////////////////

#include <stdio.h> // standard input / output functions
#include <string.h> // string function definitions
#include <unistd.h> // UNIX standard function definitions
#include <fcntl.h> // File control definitions
#include <errno.h> // Error number definitions
#include <termios.h> // POSIX terminal control definitionss
#include <time.h>   // time calls
#include <stdlib.h>
#include <stdint.h>
#include <ctype.h>
#include <vector>
#include <sys/socket.h>
#include <sys/epoll.h>

typedef struct epoll_event epoll_t;


int open_port(void)
{
	int fd = -1; // file description for the serial port
	
	fd = open("/dev/ttyUSB0", O_RDWR | O_NOCTTY | O_NDELAY | O_NONBLOCK);

	printf("Opened socket %d\n", fd);
	
	if(fd == -1) // if open is unsucessful
	{
		//perror("open_port: Unable to open /dev/ttyS0 - ");
		printf("open_port: Unable to open /dev/ttyS0. \n");
	}
	else
	{
		//fcntl(fd, F_SETFL, 0);
		printf("port is open.\n");
	}
	
	return(fd);
} //open_port

int configure_port(int fd)      // configure the port
{
		printf("Setting baud rates and shit\n");
		struct termios port_settings;      // structure to store the port settings in
		bzero(&port_settings, sizeof(struct termios));

		cfsetispeed(&port_settings, B9600);    // set baud rates
		cfsetospeed(&port_settings, B9600);

		//port_settings.c_cflag &= ~PARENB;    // set no parity, stop bits, data bits
		//port_settings.c_cflag &= ~CSTOPB;
		//port_settings.c_cflag &= ~CSIZE;
		port_settings.c_cflag |= CS8;
		//port_settings.c_cflag &= ~CRTSCTS;
		port_settings.c_cc[VMIN] = 1; // no flow control
//		port_settings.c_cc[VTIME] = 5; // 0.5 seconds read timeout
		port_settings.c_cflag |= CLOCAL;//CREAD | CLOCAL;

		//cfmakeraw(&port_settings);
		//tcflush(fd, TCIFLUSH);

		tcsetattr(fd, TCSANOW, &port_settings);    // apply the settings to the port
		return(fd);

} //configure_port

typedef union {
		char a[4];
		int32_t b;
} char2int_t;

int query_modem(int fd)   // query modem with an AT command
{
		char buf[1024] = {0};

		// check if an error has occured
		size_t len = read(fd, buf, sizeof(buf));
		//printf("Errno: %s (%d)\n", strerror(errno), errno);
		if (len == -1U)
		{
			perror("read()");
			return 0;
		}

		if (len > 0)
		{
				char c = buf[0];
				printf("0x%-8X (%c)\n", c, c);
				//fwrite(buf, len, 1, stdout);
		}

		return 0;

} //query_modem

std::vector<epoll_t> events;

int main(void)
{ 
		printf("Hello!\n");
		int fd = open_port();
		printf("Configuring port...\n");
		fd = configure_port(fd);

		events.resize(10);

		int epollfd = epoll_create(9001);
		if (epollfd == -1)
		{
				perror("epoll_create");
				return EXIT_FAILURE;
		}

		printf("Opened EPoll socket %d\n", epollfd);

		epoll_t ev;
		bzero(&ev, sizeof(epoll_t));

		ev.events = EPOLLIN;
		ev.data.fd = fd;

		if (epoll_ctl(epollfd, EPOLL_CTL_ADD, ev.data.fd, &ev) == -1)
		{
				perror("epoll_ctl");
				return EXIT_FAILURE;
		}


		printf("Entering event loop.\n");
		while(true)
		{
				int total = epoll_wait(epollfd, &events.front(), events.capacity(), 3000);
				if (total == -1)
				{
						if (errno != EINTR)
						{
								perror("epoll_wait");
								return EXIT_FAILURE;
						}
				}

				for(int i = 0; i < total; ++i)
				{
						epoll_t &ev = events[i];
						if (ev.events & (EPOLLHUP | EPOLLERR))
						{
								perror("epoll_wait");
								if (ev.events & EPOLLERR)
								{
										int       error = 0;
										socklen_t errlen = sizeof(error);
										if (getsockopt(fd, SOL_SOCKET, SO_ERROR, (void *)&error, &errlen) == 0)
										{
											printf("EPoll error: %s (%d)\n", strerror(error), error);
											return EXIT_FAILURE;
										}
								}
								else if (ev.events & EPOLLHUP)
										printf("Epoll sent EPOLLHUP\n");
								else
										printf("idfk\n");
						}

						if (ev.events & EPOLLIN)
						{
								query_modem(fd);
						}

						if (ev.events & EPOLLOUT)
						{
								printf("We're writing to the socket???\n");
						}
				}
		}

		close(fd);
		close(epollfd);

		return 0;

} //main