#
#include <stdio.h>
#include <inode.h>

/* NOTE
   To compile	cc -c ping.c
   To load	ping.ld
   To run	ping <-g> | <-i> | <-t> host

*/


/* icmpd signal info
   lock file contains process id for icmpd */
#define TFTPLCK	"/icmpd/lock"
#define UINRPT	16

/* error handling */
#define OK	0
#define ERR	-1
#define EPARM	1
#define ECFILE	2
#define EWAIT	3
#define ESHOW	4
#define ESTFTPD	5


extern int	errno;
extern char	*sys_errlist[];
int		errnum;

#define retok(value)	{ errnum = OK;		return(value); }
#define reterr(ecode)	{ errnum = ecode;	return(ERR); }

/* No. bytes in internet name */
#define	INSZ	4

/* specs from user for icmpd command file */
union {
	char	sp_hinet[INSZ];		/* foreign host internet addr */
	long	sp_hname;
} outsp;

long	resolve_name();

/* command file info */
#define CFNAME		"/icmpd/rcmdaxxxxx"
#define CFLNAME		"/icmpd/Rcmdaxxxxx"
#define NCMDLINS	2

struct cmdfl {
	char	cf_name[sizeof(CFNAME)];
	char	cf_lname[sizeof(CFNAME)];
	int	cf_leng;
	} cmdfile;

FILE	*ioptr;
int	gflag;				/* ggp request */
int	iflag;				/* icmp request */
int	tflag;				/* timestamp request */

/* inode info about command file */
struct inode	inodebf;

#define SLEEPSEC	1
#define MAXMINS		10
#define LINESIZE	128
	


main(argc, argv)
int 	argc;
char	*argv[];
{
	struct cmdfl	*cmdptr;
	int		nsecs, tcode;
	extern int	die();
	char	*hostname;

	cmdptr = &cmdfile;

	if (chkpars(argc, argv, &hostname) == ERR) exit(errnum);

	if (mkcmd(cmdptr) == ERR) exit(errnum);

	signal(2, &die);

	if (sigicmp(cmdptr) == ERR) delexit(cmdptr, errnum);

	printf("Pinging %s at %o,%o,%o,%o:    ", hostname,
		outsp.sp_hinet[0] & 0377, outsp.sp_hinet[1] & 0377,
		outsp.sp_hinet[2] & 0377, outsp.sp_hinet[3] & 0377);

	if ((nsecs = icmpwt(cmdptr)) == ERR) delexit(cmdptr, errnum); 

	tcode = showend(hostname, cmdptr, nsecs);

	delexit(cmdptr, tcode);	
}

die()
{
	delexit(&cmdfile, -1);
}

chkpars(argc, argv, nameptr)
int		argc;
char		*argv[];
char	**nameptr;
{
	int i;

	if (argc < 2 || argc >4) {
		errarg("wrong number of arguments");
		reterr( EPARM );
		}

	for (i = 1; i < argc; i++)
		if (argv[i][0] == '-')
			switch (argv[i][1]) {
			case 'g':
				gflag++;
				break;
			case 'i':
				iflag++;
				break;
			case 't':
				tflag++;
				break;
			default:
				errarg("bad flag");
				reterr(EPARM);
			}
		else {
			*nameptr = argv[i];
			outsp.sp_hname = resolve_name(argv[i]);
			if (outsp.sp_hname == 0L) {
				printf ("No such host as %s\n", argv[i]);
				reterr(EPARM);
			}
		}

	retok( OK );
}

errarg(msg)
char	*msg;
{
	printf("Ping %s\n",msg);
	printf("Ping usage:  ping [-g]|[-i]|[-t] <host>\n");

	retok( OK );
}

mkcmd(cmdptr)
struct cmdfl	*cmdptr;
{
	struct inode	*statptr;

	mktmpn(cmdptr);
	
	if ( (ioptr = fopen(cmdptr->cf_name,"w")) == NULL) {
		printf("Ping   cannot open temp. command file %s\n",
						cmdptr->cf_name);
		unlink(cmdptr->cf_name);
		reterr(ECFILE);
		}

	if (gflag)
		putsnl("ggp echo",ioptr);
	else if (tflag)
		putsnl("timestamp",ioptr);
	else
		putsnl("icmp echo",ioptr);

	fprintf(ioptr,"%o,%o,%o,%o\n",outsp.sp_hinet[0] & 0377,
		outsp.sp_hinet[1] & 0377,outsp.sp_hinet[2] & 0377,
		outsp.sp_hinet[3] & 0377);

	fclose(ioptr);

	statptr = &inodebf;
	stat(cmdptr->cf_name, statptr);
	cmdptr->cf_leng = statptr->size1;

	retok( OK );
}

mktmpn(cmdptr)
struct cmdfl	*cmdptr;
{
	int	pid;
	int	i, ip;
	char	ch;

	strcpy(cmdptr->cf_name,CFNAME);
	strcpy(cmdptr->cf_lname,CFLNAME);

	ip = sizeof(CFNAME);

	pid = getpid();

	for ( i = 2; i <= 6; i++) {
		ch = (pid & 07) + '0';
		cmdptr->cf_name[ip-i] = ch;
		cmdptr->cf_lname[ip-i] = ch;
		pid =>> 3;
		}

	retok( OK );
}

puts1(chp, iop)
char	*chp;
FILE	*iop;
{
	char	*s;

	for (s = chp; *s; s++) 
		putc(*s, iop);

	retok( OK );
}

putsnl(chp, iop)
char	*chp;
FILE	*iop;
{
	char	*s;

	for (s = chp; *s; s++) 
		putc(*s, iop);

	putc('\n', iop);

	retok( OK );
}

puthex(chp, chn, iop)
char	*chp;
int	chn;
FILE	*iop;
{
	static char	hexstr[]	"0123456789ABCDEF";
	char		buf[2];
	register int	i, tmp;

	for (i = 0; i < chn; i++) {
		tmp = *chp++;
		buf[1] = hexstr[(tmp & 0xf)];
		buf[0] = hexstr[((tmp >> 4) & 0xf)];
		putc(buf[0], iop);
		putc(buf[1], iop);
		}
	putc('\n',iop);

	retok(OK);
}

/* 
 * sigicmp
 * read icmp daemon's process id from lock file
 * link Rcmd name to identify command file for icmpd
 * signal icmpd
*/
sigicmp(cmdptr)
struct cmdfl	*cmdptr;
{
	int	lockfl;
	char	procch[16];
	int	procid;

	if ( (lockfl = open(TFTPLCK, 0)) == ERR) {
		printf("Ping  icmp daemon not alive\n");
		reterr( ESTFTPD );
		}

	read(lockfl, procch, 16);
	close(lockfl);

	procid = atoi(procch);
	if (procid <= 0) {
		printf("Ping  cannot signal icmp daemon\n");
		reterr( ESTFTPD );
		}

	link(cmdptr->cf_name, cmdptr->cf_lname);
	if (kill(procid, UINRPT) == ERR) {
		printf("Ping   cannot signal icmp daemon\n");
		reterr( ESTFTPD );
		}

	retok( OK );
}

icmpwt(cmdptr)
struct cmdfl	*cmdptr;
{
	struct inode	*statptr;
	int		nsecs;

	nsecs = 0;

	statptr = &inodebf;
	stat(cmdptr->cf_name, statptr);

	while (cmdptr->cf_leng == statptr->size1)  {
		sleep(SLEEPSEC);

		if (stat(cmdptr->cf_name, statptr) == ERR) {
			printf("Ping  error %d on status call for file %s\n",
				errno, cmdptr->cf_name);
			reterr( EWAIT );
			}

		nsecs += SLEEPSEC;
		if (nsecs > (60 * MAXMINS)) {
			printf("Ping  waited for %d minutes for transfer to complete, will quit waiting\n",(nsecs/60));
			reterr( EWAIT );
			}
		}

	retok( nsecs );
}

showend(hostname, cmdptr, nsec)
char	*hostname;
struct cmdfl	*cmdptr;
int		nsec;
{
	int		i;
	char		line[LINESIZE + 1];
	char		*p;
	int		tcode, epcode;
	long		size;
	float		baud;

	if ( (ioptr = fopen(cmdptr->cf_name, "r")) == NULL)  {
		printf("Ping  cannot open %s for reading\n",cmdptr->cf_name);
		reterr( ESHOW );
		}

	for (i = 0; i <= (NCMDLINS); i++) 
		fgets(line, LINESIZE, ioptr);

	sscanf (line, "%*[^=]=%d\n", &tcode);
	if (tcode > 0) {
		printf ("system error %d\n%s\n", tcode, sys_errlist[tcode]);
		retok(tcode);
	} else
		while (fgets(line, LINESIZE, ioptr) != NULL)
			printf("%s",line);
	retok(tcode);
}

delexit(cmdptr, tcode)
struct cmdfl	*cmdptr;
int		tcode;
{
	unlink(cmdptr->cf_name);
	unlink(cmdptr->cf_lname);

	exit(tcode);
}