/*
 * <spd@daphne.cps.unizar.es>
 * Thu Oct 28 14:26:43 CEST 2010
 *
 * :set tabstop=4
 *
 */

static char __ident[] = "@(#)SPDsoft, Thu Oct 28 14:26:43 CEST 2010";
#define VERS_STR        ((char*)&__ident[4])


#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>  /* atoi */
#include <ctype.h>
#if defined(__MACH__) && defined(__APPLE__)
#include <stdint.h>
#endif
#include <unistd.h>  /* getpid */
#include <fcntl.h>
#include <string.h>


#include <sys/time.h>  
#include <sys/types.h>  
#include <sys/socket.h> 
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>  
#ifdef __linux__
#include <grp.h>
#else
#include <sys/param.h>
#endif
#include <time.h>  

#include <sys/ioctl.h>

#include <signal.h>
#include <sys/wait.h>

#include <errno.h>  

#define BS 4096


#ifdef __sgi
#	define HAVE_DAEMONIZE
#endif
#ifdef __linux__

#	define HAVE_DAEMON
#	define _DF_NOCHDIR     1
#	define _daemonize(a,b,c,d) daemon((a),0)

#	define _POSIX_SIGNALS

#	define	NOBODY 99
#	define	NOGROUP 99

#else

#	ifndef HAVE_DAEMONIZE
/* _daemonize(3C) flags */
#	define _DF_NOFORK      0x1     /* don't fork */
#	define _DF_NOCHDIR     0x2     /* don't chdir to / */
#	define _DF_NOCLOSE     0x4     /* close no files */

	int my_daemonize(int flags, int fd1, int fd2, int fd3);
#	define _daemonize my_daemonize
#	define MY_DAEMONIZE
#	endif

#	define	NOBODY 60001
#	define	NOGROUP 60001

#endif



#define HAVE_SETSID 1 /* irix, linux, solaris */
#define HAVE_STRERROR 1

#ifndef  HAVE_STRERROR
#	define strerror(e) sys_errlist[(e)]
#endif

#ifndef _POSIX_SIGNALS
#ifndef _SYSV_SIGNALS
#	define _BSD_SIGNALS
#endif
#ifdef _BSD_SIGNALS
#	define sigset	signal
#endif
#endif

#ifndef DEFAULT_TPORT
#	define DEFAULT_TPORT 8001
#endif


typedef struct {
		unsigned int	port;
		int				debug;
		char			*bindh;
		char			*logfile;
		FILE			*f;
	} prefs_struct;

prefs_struct    gprefs;


int						s;
int						done;

/*
 * Prototypes
 */

void clean( int i );
void debug_msg(const char *fmt, ...);
void log_msg(const char *fmt, ...);



void debug_msg(const char *fmt, ...)
{
	va_list	vl;
	if (gprefs.debug && ( NULL != gprefs.f))
	{
		va_start(vl,fmt);
			vfprintf(gprefs.f,fmt,vl);
		va_end(vl);
		fflush(gprefs.f);
	}
}

void log_msg(const char *fmt, ...)
{
	va_list	vl;
	if ( NULL != gprefs.f)
	{
		va_start(vl,fmt);
			vfprintf(gprefs.f,fmt,vl);
		va_end(vl);
		fflush(gprefs.f);
	}
}


int main(int argc, char *argv[])
{
	long					nbytes;
	int						sockfd;
	int						queue;
	struct sockaddr_in		server,
							client;
#ifdef __linux__
	socklen_t				clientlen=sizeof(client);
#else
	int						clientlen=sizeof(client);
#endif
	char					buf[BS];
	int                     reuse=1;

	time_t					timer;
	int						option;

#ifdef _POSIX_SIGNALS
	struct sigaction		sigact;   /* Signal action */
#endif

	gprefs.port=DEFAULT_TPORT;
	gprefs.debug=0;
	gprefs.logfile=NULL;
	gprefs.bindh=NULL;
	gprefs.f=stderr;


	while ( (option=getopt(argc,argv,"hvdl:b:p:")) != EOF )
	{
		switch(option)
		{
			case 'b':
				gprefs.bindh = optarg;
				break;
			case 'l':
				gprefs.logfile = optarg;
				break;
			case 'd':
				gprefs.debug = 1;
				break;
			case 'p':
				gprefs.port = (unsigned int) atoi(optarg);
				break;
			case 'v':
				fprintf(stdout, "%s\n",VERS_STR);
				exit(0);
				break;
			case 'h':
			default:
				fprintf(stdout, "Use: %s [-hdv] [-l log] [-b bind] [-p port]\n", argv[0]);
				exit(0);
		}
	}


	memset(&server,0,sizeof(server));

	
	if ( !gprefs.debug )
	{
		if ( -1 == _daemonize(_DF_NOCHDIR,
			gprefs.f != NULL ? fileno(gprefs.f) : -1, -1,-1))
		perror("Can't daemonize");
	}


	server.sin_family =			AF_INET;
	server.sin_port =			htons(gprefs.port);
	server.sin_addr.s_addr =	htonl(INADDR_ANY);

	if (gprefs.bindh != NULL )
		server.sin_addr.s_addr = inet_addr(gprefs.bindh);



	queue=1;

/* Set up a signal handler for SIGINT.  The signal is sent to the
 * process when the user presses <ctrl>c.
 */

#ifdef _POSIX_SIGNALS
	sigemptyset(&sigact.sa_mask);
	sigact.sa_flags = 0;
	sigact.sa_handler = clean;
	if (
		(sigaction(SIGTERM, &sigact, NULL) != 0) ||
		(sigaction(SIGINT, &sigact, NULL) != 0)
		)
		perror("sigaction(SIGINT) failed");
#else
	if (
		( SIG_ERR == sigset(SIGTERM, clean)) ||
		( SIG_ERR == sigset(SIGINT, clean))  )
		perror("signal");
#endif

	debug_msg("open socket %d\n", s);

	if ( (s=socket(AF_INET,SOCK_STREAM,0)) == -1 )
	{
		perror("socket");
		exit(1);
	}

	if (setsockopt(s, SOL_SOCKET,SO_REUSEADDR,&reuse,sizeof(int)) == -1)
	{
		perror("setsockopt");
	}

	debug_msg("bind to %s\n", inet_ntoa(server.sin_addr));

	if( bind( s, (struct sockaddr *)&server, sizeof(server)) != 0 )
	{	
		perror("bind");
		exit(1);
	}

	if ( NULL != gprefs.logfile )
	{
		if ( NULL == ( gprefs.f = fopen(gprefs.logfile, "wb")))
		{
			perror(optarg);
			gprefs.logfile = NULL;
		}
	}

	done=0;

	setgroups(0, NULL);

    if (-1==setegid(NOBODY))
		perror("setegid");
    if (-1==setgid(NOGROUP))
		perror("setgid");
    if (-1==setuid(NOBODY))
		perror("setuid");


	if ( listen( s, queue ) != 0 )
	{
		perror("listen");
		exit(1);
	}
		
	for(;!done; )
	{
		debug_msg("%d accepting\n", getpid());

		if( (sockfd = accept(s,(struct sockaddr *)&client,&clientlen)) < 0 )
		if ( errno != EINTR )
		{
			perror("accept");
			break;
		}
		else
			continue;

		time(&timer);
		if (
			(0==strcmp(inet_ntoa(client.sin_addr),"155.210.152.20")) ||
			(0==strcmp(inet_ntoa(client.sin_addr),"155.210.152.24"))
			)
		{
			debug_msg("accepted from %s\n", inet_ntoa(client.sin_addr));
		}
		else
		{
			log_msg("REJECTED from %s - %s",
				inet_ntoa(client.sin_addr),
				ctime(&timer)
				);
			shutdown(sockfd,2);
			close(sockfd);
			sockfd=0;
			continue;
		}

		nbytes = recv(sockfd,buf,sizeof(buf),0);
		buf[nbytes]=0x00;
		{
			char cmd[BS];
			FILE        *cmdf;
			size_t      n,m;
			m=strlen(buf);
			for (n=0; n<m; n++)
			{
				if ( isprint (buf[n]) )
					;
				else
				{
					buf[n]=0x00;
					n=m;
				}
			}

			if (0==strncmp(buf,"1TEMP",5))
			{
				sprintf(cmd,"/usr/local/etc/env/ghot");
			}
			else if (0==strncmp(buf,"2_UPS",5))
			{
				sprintf(cmd,"/usr/local/etc/env/ups");
			}
			else if (0==strncmp(buf,"4_UPS",5))
			{
				sprintf(cmd,"/usr/local/etc/env/ups2");
			}
			else if (0==strncmp(buf,"5_UPS",5))
			{
				sprintf(cmd,"/usr/local/etc/env/ups3");
			}
			else if (0==strncmp(buf,"3TEMP",5))
			{
				sprintf(cmd,"/usr/local/etc/env/hotmon-sys");
			}
			else
			{
				sprintf(cmd,"echo ACCESS DENIED");
			}
			log_msg("%s - %s - %s",
				inet_ntoa(client.sin_addr),
				buf,
				ctime(&timer)
				);

			debug_msg("MSG: %d \"%s\"\n",n,buf);
			debug_msg("CMD: %s\n", cmd);
			if ( NULL == ( cmdf = popen( cmd, "r")))
			{
				debug_msg("ERROR\n");
			}
			else
			{
				while ( 0 != ( n = fread( cmd, 1, BS, cmdf )))
				{
					cmd[n]=0x00;
					debug_msg("OUT: %s\n",cmd);fflush(stderr);
					write(sockfd,cmd,n);
				}
				pclose(cmdf);
			}
		}


		shutdown(sockfd,2);
		close(sockfd);
		sockfd=0;
	}

	if ( sockfd != 0 )
	{
		debug_msg("close and shutdown\n");
		shutdown(sockfd,2);
		close(sockfd);
		sockfd=0;
	}
	if ( s != 0 )
	{
		if ( -1 == close(s))
			perror("close");
	}


	exit(errno);
}

/************************************************************************/

void clean( int sig )
{
#ifndef _POSIX_SIGNALS
	if ( SIG_ERR == sigset(sig, clean))
		perror("clean:signal");
#endif

	fprintf(stderr,"%d a escaparrar (%d)\n", getpid(), sig);
	done=1;
}

/************************************************************************/

#ifdef MY_DAEMONIZE
int my_daemonize(int flags, int fd1, int fd2, int fd3)
{
	int status=0;
	int fd;

/*	debug_msg("daemonizing\n");*/

	if (!( flags & _DF_NOFORK ))
	{
		/* Fork and exit in the parent to disassociate from the
		 * current process group and become the leader of a new
		 * process group.
		 */

		if ( -1 == (status = fork()))
		{
			perror("cant fork");
			exit(1);
		}
		else if ( status > 0 )
		{
			_exit(0);
		}

#if HAVE_SETSID
		setsid();
#endif


		if ( -1 == (status = fork()))
		{
			perror("cant fork again");
			exit(1);
		}
		else if ( status > 0 )
		{
			_exit(0);
		}
	}


#ifdef TIOCNOTTY
	if ( 0 < (fd = open("/dev/tty", O_RDWR)))
	{
		if (ioctl(fd, TIOCNOTTY, NULL) < 0)
		{
			perror("can't disassociate from the terminal");
			status=-1;
		}
		close(fd);
	}
#endif /* TIOCNOTTY */

	if (!(flags & _DF_NOCHDIR))
	{
		if (chdir("/.") < 0)
		{
			perror("can't chdir to /.");
			status=-1;
		}
	}

	if (!(flags & _DF_NOCLOSE))
	{
		long l;
		int	i;

		l=sysconf(_SC_OPEN_MAX);

		while(l-->0)
		{
			if ((l!=fd1)&&(l!=fd2)&&(l!=fd3))
				close(l);
		}

		if ( -1 == ( i = open( "/dev/null", O_RDWR)))
		{
			perror("/dev/null");
			status=-1;
		}
		else
		{
			if ((1!=fd1)&&(1!=fd2)&&(1!=fd3))
				dup(i);
			if ((2!=fd1)&&(2!=fd2)&&(2!=fd3))
				dup(i);
		}
	}
	return(status);
}
#endif