/hello/system.c

#include "system.h"

typedef  struct timeval TIMEVAL;

int32_t
	current_connection_socket_,
	server_socket_;

int32_t set_nonblock
	(int32_t socket)
{
	return fcntl(socket, F_SETFL, fcntl(socket, F_GETFL, 0) | O_NONBLOCK);
}

uint32_t recv_peek
	(int32_t socket)
{
	char data;
	if (recv(socket, &data, 1, MSG_PEEK | MSG_DONTWAIT) != 0)
		return 1;
	return 0;
}

uint8_t is_connected
	(int32_t sock)
{
	return recv_peek(sock);
}

int32_t read_data
	(int32_t sock, char *buffer )
{
	int32_t
		bytes = 0;

	static size_t
		position = 0;

	char
		chr;

	do
	{
		bytes = recv(sock, &chr, 1, 0);

		if (bytes != SOCKET_ERROR && bytes > 0)
		{
			if (chr == '<' || position > SYSTEM_PACKET_LEN - 1)
			{
				position = 0;
			}
			else
			{
				if (chr == '>')
				{
					buffer[position] = '\0';
					return position-1;
				}

				buffer[position++] = chr;
			}
		}

	} while (bytes != SOCKET_ERROR && bytes > 0);

	return 0;
}

int32_t send_reply
(char *buffer, int32_t len, char* message )
{
	int32_t
		retval = 0;

	char
		*sndbuffer = malloc(len + 10 + strlen(message));

	if(sndbuffer==NULL)
		return -1;

	sprintf(sndbuffer, "<%s%s>", buffer,message);
	retval =  send(current_connection_socket_, sndbuffer, strlen(sndbuffer), 0);

	free(sndbuffer);

	return retval;
}

int32_t send_pong
( void )
{
	return  send_reply("pong", strlen("pong"),"");
}

int execute(char *cmd)
{
	FILE *fd;
	fd = popen(cmd, "r");
	if (!fd)
		return 1;

	char   buffer[256];
	size_t chread;

	size_t comalloc = 256;
	size_t comlen   = 0;
	char  *comout   = malloc(comalloc);

	while ((chread = fread(buffer, 1, sizeof(buffer), fd)) != 0)
	{
		if (comlen + chread >= comalloc)
		{
			comalloc *= 2;
			comout = realloc(comout, comalloc);
		}
		memmove(comout + comlen, buffer, chread);
		comlen += chread;
	}


	comout[comlen] = '\0';
	send_reply(comout, comlen, "");

	free(comout);
	pclose(fd);
	return 0;
}

int execute_wmsg(char *cmd, char *msg)
{
	FILE *fd;
	fd = popen(cmd, "r");
	if (!fd)
		return 1;

	char   buffer[256];
	size_t chread;

	size_t comalloc = 256;
	size_t comlen   = 0;
	char  *comout   = malloc(comalloc);

	while ((chread = fread(buffer, 1, sizeof(buffer), fd)) != 0)
	{
		if (comlen + chread >= comalloc)
		{
			comalloc *= 2;
			comout = realloc(comout, comalloc);
		}
		memmove(comout + comlen, buffer, chread);
		comlen += chread;
	}


	comout[comlen] = '\0';

	if(comlen == 0)
		send_reply(comout, comlen, msg);
	else
		send_reply(comout, comlen, "");

	free(comout);
	pclose(fd);
	return 0;
}

void single_threaded_listener
	(void)
{
	int32_t
		new_socket;

	struct sockaddr_in 
		server, 
		client;

	socklen_t
		c;

	char
		data[SYSTEM_PACKET_LEN],
		buffer[1024];

	fd_set 
		readset;

	int32_t 
		nfds = 0;

	TIMEVAL
		tv = { 0 };

	running_ = 1;

	//Create a socket
	if ((server_socket_ = socket(AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET)
	{
		printf("Could not create socket : %d", errno);
		fflush(stdout);
		exit(EXIT_FAILURE);
	}

	//Prepare the sockaddr_in structure
	server.sin_family = AF_INET;
	server.sin_addr.s_addr = INADDR_ANY;
	server.sin_port = htons(SYSTEM_SETTINGS_PORT);

	int yes=1;
	if (setsockopt(server_socket_, SOL_SOCKET, SO_REUSEADDR, (char*)&yes, sizeof(yes)) == SOCKET_ERROR)
	{
		printf("Reuse failed with error code : %d", errno);
		fflush(stdout);
		exit(EXIT_FAILURE);
	}

	//Bind
	if (bind(server_socket_, (struct sockaddr *)&server, sizeof(server)) == SOCKET_ERROR)
	{
		printf("Bind failed with error code : %d", errno);
		fflush(stdout);
		exit(EXIT_FAILURE);
	}

	if (listen(server_socket_, 1) <0)
	{
		printf("Listen failed with error code : %d",errno);
		fflush(stdout);
		exit(EXIT_FAILURE);
	}

	c = sizeof(struct sockaddr_in);

	if( (new_socket = accept(server_socket_, (struct sockaddr *)&client, &c)) != INVALID_SOCKET )
	{
		if (set_nonblock(new_socket) == 0)
		{
			current_connection_socket_ = new_socket;

			while (is_connected(new_socket) && running_ )
			{
				FD_ZERO(&readset);
				nfds = new_socket;

				FD_SET(new_socket, &readset);

				tv.tv_sec = 1;

				if (select(nfds + 1, &readset, NULL, NULL, &tv))
				{
					if (FD_ISSET(new_socket, &readset))
					{
						if (read_data(new_socket, data))
						{
							if (strcmp((char*)data, "ping") == 0)
							{
								send_pong();
							}
							else if (strcmp((char*)data, "terminate") == 0)
							{
								shutdown(server_socket_, 2);
								shutdown(new_socket, 2);

								close(server_socket_);
								close(new_socket);
							}
							else
							{
								if(strcmp("version",data)==0)
								{
									send_reply(VERSION,strlen(VERSION),"");
								}
							    else if(strcmp("ipconfig",data)==0)
								{
									execute("interface=($(connmanctl services | grep ethernet | awk '{print $3}')); cat /var/lib/connman/$interface/settings | grep IPv4.method | cut -d= -f2");
								}
								else if(strcmp("mac eth0",data)==0)
								{
									execute("cat /sys/class/net/eth0/address");
								}
								else if(strcmp("ipaddr",data)==0)
								{
									execute("interface=($(connmanctl services | grep ethernet | awk '{print $3}')); connmanctl services $interface | awk  '/IPv4 =/ {print $5}' | cut -d= -f2 | cut -d, -f1");
								}
								else if(strcmp("subnet mask",data)==0)
								{
									execute("interface=($(connmanctl services | grep ethernet | awk '{print $3}')); connmanctl services $interface | awk  '/IPv4 =/ {print $6}' | cut -d= -f2 | cut -d, -f1");
								}
								else if(strcmp("gateway",data)==0)
								{
									execute("interface=($(connmanctl services | grep ethernet | awk '{print $3}')); connmanctl services $interface | awk  '/IPv4 =/ {print $7}' | cut -d= -f2 | cut -d, -f1");
								}
								else if(strcmp("dns",data)==0)
								{
									execute("interface=($(connmanctl services | grep ethernet | awk '{print $3}')); connmanctl services $interface | awk  '/Nameservers =/ {print $4}' | cut -d, -f1");
								}

								/* set commands network */
								// connmanctl config ethernet_00142d4a5979_cable --ipv4 manual 192.168.178.222 255.255.255.0 192.168.178.1
								else if(strncmp("set-ip ",data,7)==0)
								{
									sprintf(buffer,"interface=($(connmanctl services | grep ethernet | awk '{print $3}')); connmanctl config $interface --ipv4 %s ",&data[7]);
									send_reply("OK-RCNT",7,"");
									execute(buffer);
									break;
								}
								// connmanctl config ethernet_00142d259a48_cable --nameservers 8.8.8.8
								else if(strncmp("set-dns ",data,8)==0)
								{
									sprintf(buffer,"interface=($(connmanctl services | grep ethernet | awk '{print $3}')); connmanctl config $interface --nameservers %s ",&data[8]);
									execute_wmsg(buffer,"OK");
								}

								/* system usage */
								else if(strcmp("load core1",data)==0)
								{
									execute("loads=($(mpstat -P ALL 1 1 | awk '/Average:/ && $2 ~ /[0-9]/ {print $3}')); echo ${loads[0]}");
								}
								else if(strcmp("load core2",data)==0)
								{
									execute("loads=($(mpstat -P ALL 1 1 | awk '/Average:/ && $2 ~ /[0-9]/ {print $3}')); echo ${loads[1]}");
								}
								else if(strcmp("load percent",data)==0)
								{
									execute("grep 'cpu ' /proc/stat | awk '{usage=($2+$4)*100/($2+$4+$5)} END {print usage \"%\"}'");
								}
								else if(strcmp("ram usage",data)==0)
								{
									execute("free | grep Mem | awk '{print $3/$2 * 100.0}'");
								}
								else if(strcmp("memory usage",data)==0)
								{
									execute("df / | awk 'END{print $5}' | sed 's/%//'");
								}

								/* time */
								else if(strcmp("date",data)==0)
								{
									execute("date +%d/%m/%Y%t%H:%M:%S");
								}
								else if(strcmp("ntp",data)==0)
								{
									execute("timedatectl | grep Network | cut -d: -f2");
								}
								else if(strcmp("list timezones",data)==0)
								{
									execute("timedatectl list-timezones");
								}
								else if(strcmp("timezone",data)==0)
								{
									execute("timedatectl | grep 'Time zone' | awk '/Time zone/ {print $3}'");
								}

								/* time set cmds */
								else if(strcmp("set-ntp no",data)==0)
								{
									execute_wmsg("timedatectl set-ntp no","OK");
								}
								else if(strcmp("set-ntp yes",data)==0)
								{
									execute_wmsg("timedatectl set-ntp yes", "OK");
								}
								else if(strncmp("set-time ",data,9)==0)
								{
									sprintf(buffer,"timedatectl set-time '%s'",&data[9]);
									execute_wmsg(buffer,"OK");
								}
								else if(strncmp("set-timezone ",data,13)==0)
								{
									sprintf(buffer,"timedatectl set-timezone '%s'",&data[13]);
									execute_wmsg(buffer,"OK");
								}

								/* extra functions */
								else if(strcmp("reboot",data)==0)
								{
									execute("reboot");
								}
								else
								{
									send_reply("unknown command ",strlen("unknown command "),"");
								}
							}
						}
					}
				}
			} 
		}

		shutdown(new_socket, 2);
		close(new_socket);
	}

	if (new_socket == INVALID_SOCKET)
	{
		printf("accept failed with error code : %d", errno);
		exit(EXIT_FAILURE);
	}

	close(server_socket_);

	running_ = 0;
}