/**
 * PING module
 *
 * Copyright (C) 2001 Jeffrey Fulmer <jdfulmer@armstrong.com>
 * This file is part of LIBPING
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * --
 *
 * This code has been lightly modified to adapt it in the Netsukuku source
 * code.
 */
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <pthread.h>
#include <stdlib.h>

#include "libping.h"
#include "xmalloc.h"
#include "log.h"

#define  MAXPACKET   65535
#define  PKTSIZE     64
#define  HDRLEN      ICMP_MINLEN
#define  DATALEN     (PKTSIZE-HDRLEN)
#define  MAXDATA     (MAXPKT-HDRLEN-TIMLEN)
#define  DEF_TIMEOUT 5

struct ping_priv
ping_priv_default(void)
{
	struct ping_priv datum;
	datum.ident = IDENT_DEFAULT;
	datum.timo = TIMO_DEFAULT;
	return datum;
}

/**
 * elapsed_time
 * returns an int value for the difference
 * between now and starttime in milliseconds.
 */
int
elapsed_time(struct timeval *starttime)
{
	struct timeval *newtime;
	int elapsed;
	newtime = (struct timeval *) xmalloc(sizeof(struct timeval));
	gettimeofday(newtime, NULL);
	elapsed = 0;

	if ((newtime->tv_usec - starttime->tv_usec) > 0) {
		elapsed += (newtime->tv_usec - starttime->tv_usec) / 1000;
	} else {
		elapsed +=
			(1000000 + newtime->tv_usec - starttime->tv_usec) / 1000;
		newtime->tv_sec--;
	}
	if ((newtime->tv_sec - starttime->tv_sec) > 0) {
		elapsed += 1000 * (newtime->tv_sec - starttime->tv_sec);
	}
	if (elapsed < 1)
		elapsed = 1;

	xfree(newtime);
	return (elapsed);
}

void
JOEfreeprotoent(struct protoent *p)
{
	char **a;
	xfree(p->p_name);
	if (p->p_aliases != NULL) {
		for (a = p->p_aliases; *a != NULL; a++) {
			xfree(*a);
		}
	}
	xfree(p);
}

void
JOEfreehostent(struct hostent *h)
{
	char **p;

	xfree(h->h_name);
	if (h->h_aliases != NULL) {
		for (p = h->h_aliases; *p != NULL; ++p)
			xfree(*p);
		xfree(h->h_aliases);
	}
	if (h->h_addr_list != NULL) {
		for (p = h->h_addr_list; *p != NULL; ++p)
			xfree(*p);
		xfree(h->h_addr_list);
	}
	xfree(h);
}

static int
in_checksum(u_short * buf, int len)
{
	register long sum = 0;
	u_short answer = 0;

	while (len > 1) {
		sum += *buf++;
		len -= 2;
	}

	if (len == 1) {
		*(u_char *) (&answer) = *(u_char *) buf;
		sum += answer;
	}
	sum = (sum >> 16) + (sum & 0xffff);
	sum += (sum >> 16);
	answer = ~sum;

	return (answer);

}

static int
send_ping(const char *host, struct sockaddr_in *taddr,
		  struct ping_priv *datum)
{
	int len;
	int ss;
	unsigned char buf[HDRLEN + DATALEN];

#define PROTO_BUF_LEN	1024
	char proto_buf[PROTO_BUF_LEN];
	struct protoent *proto = NULL;
	struct protoent proto_datum;

	struct hostent *hp = NULL;
	struct hostent hent;
	int herrno;
	char hbf[9000];
#if defined(_AIX)
	char *aixbuf;
	char *probuf;
	int rc;
#endif/*_AIX*/

	struct icmp *icp;
	unsigned short last;

	len = HDRLEN + DATALEN;

#if defined(__GLIBC__)
	/* for systems using GNU libc */
	getprotobyname_r("icmp", &proto_datum, proto_buf, PROTO_BUF_LEN,
					 &proto);
	if ((gethostbyname_r(host, &hent, hbf, sizeof(hbf), &hp, &herrno) < 0)) {
		hp = NULL;
	}
#elif defined(sun)
	/* Solaris 5++ */
	proto =
		getprotobyname_r("icmp", &proto_datum, proto_buf, PROTO_BUF_LEN);
	hp = gethostbyname_r(host, &hent, hbf, sizeof(hbf), &herrno);
#elif defined(_AIX)
	aixbuf = (char *) xmalloc(9000);
	probuf = (char *) xmalloc(9000);
	rc = getprotobyname_r("icmp", &proto,
						  (struct protoent_data *) (probuf +
													sizeof(struct
														   protoent)));
	rc = gethostbyname_r(host, (struct hostent *) aixbuf,
						 (struct hostent_data *) (aixbuf +
												  sizeof(struct hostent)));
	hp = (struct hostent *) aixbuf;
#elif ( defined(hpux) || defined(__osf__) )
	proto = getprotobyname("icmp");
	hp = gethostbyname(host);
	herrno = h_errno;
#else
	/* simply hoping that get*byname is thread-safe */
	proto = getprotobyname("icmp");
	hp = gethostbyname(host);
	herrno = h_errno;
#endif							/*OS SPECIFICS */

	if (proto == NULL) {
		return -1;
	}

	if (hp != NULL) {
		memcpy(&taddr->sin_addr, hp->h_addr_list[0],
			   sizeof(taddr->sin_addr));
		taddr->sin_port = 0;
		taddr->sin_family = AF_INET;
	} else if (inet_aton(host, &taddr->sin_addr) == 0) {
		return -1;
	}

	last = ntohl(taddr->sin_addr.s_addr) & 0xFF;
	if ((last == 0x00) || (last == 0xFF)) {
		return -1;
	}

	if ((datum->sock = socket(AF_INET, SOCK_RAW, proto->p_proto)) < 0) {
#ifdef  DEBUG
		debug(DBG_NORMAL, ERROR_MSG "sock: %s" ERROR_POS, strerror(errno));
#endif	 /*DEBUG*/
			return -2;
	}

	icp = (struct icmp *) buf;
	icp->icmp_type = ICMP_ECHO;
	icp->icmp_code = 0;
	icp->icmp_cksum = 0;
	icp->icmp_id = getpid() & 0xFFFF;
	icp->icmp_cksum = in_checksum((u_short *) icp, len);

	if ((ss = sendto(datum->sock, buf, sizeof(buf), 0,
					 (struct sockaddr *) taddr, sizeof(*taddr))) < 0) {
#ifdef  DEBUG
		debug(DBG_NORMAL, ERROR_MSG "sock: %s" ERROR_POS, strerror(errno));
#endif	 /*DEBUG*/
			return -2;
	}
	if (ss != len) {
#ifdef  DEBUG
		debug(DBG_NORMAL, ERROR_MSG "sock: %s" ERROR_POS, strerror(errno));
#endif	 /*DEBUG*/
			return -2;
	}
#if defined(_AIX)
	xfree(aixbuf);
	xfree(probuf);
#endif
	/* JOEfreeprotoent( proto ); */
	/* JOEfreeprotoent( &proto_datum ); */
	/* JOEfreehostent( hp ); */
	/* JOEfreehostent( &hent ); */
	return 0;
}

static int
recv_ping(struct sockaddr_in *taddr, struct ping_priv *datum)
{
	int len;
	int from;
	int nf, cc;
	unsigned char buf[HDRLEN + DATALEN];
	//struct icmp *icp;
	struct sockaddr_in faddr;
	struct timeval to;
	fd_set readset;

	to.tv_sec = datum->timo / 100000;
	to.tv_usec = (datum->timo - (to.tv_sec * 100000)) * 10;

	FD_ZERO(&readset);
	FD_SET(datum->sock, &readset);
	/* we use select to see if there is any activity
	   on the socket.  If not, then we've requested an
	   unreachable network and we'll time out here. */
	if ((nf = select(datum->sock + 1, &readset, NULL, NULL, &to)) < 0) {
		datum->rrt = -4;
#ifdef  DEBUG
		debug(DBG_NORMAL, ERROR_MSG "sock: %s" ERROR_POS, strerror(errno));
#endif	 /*DEBUG*/
			return 0;
	}
	if (nf == 0) {
		return -1;
	}

	len = HDRLEN + DATALEN;
	from = sizeof(faddr);

	cc = recvfrom(datum->sock, buf, len, 0, (struct sockaddr *) &faddr,
				  (socklen_t *) & from);
	if (cc < 0) {
		datum->rrt = -4;
#ifdef  DEBUG
		debug(DBG_NORMAL, ERROR_MSG "sock: %s" ERROR_POS, strerror(errno));
#endif	 /*DEBUG*/
			return 0;
	}

	//icp = (struct icmp *) (buf + HDRLEN + DATALEN);
	if (faddr.sin_addr.s_addr != taddr->sin_addr.s_addr) {
		return 1;
	}
  /*****
  if( icp->icmp_id   != ( getpid() & 0xFFFF )){
    printf( "id: %d\n",  icp->icmp_id );
    return 1; 
  }
  *****/
	return 0;
}

int
myping(const char *hostname, int t, struct ping_priv *datum)
{
	int err;
	int rrt;
	struct sockaddr_in sa;
	struct timeval mytime;

	datum->ident = getpid() & 0xFFFF;

	if (t == 0)
		datum->timo = 2;
	else
		datum->timo = t;

	datum->rrt = 0;

	(void) gettimeofday(&mytime, (struct timezone *) NULL);
	if ((err = send_ping(hostname, &sa, datum)) < 0) {
		close(datum->sock);
		return err;
	}
	do {
		rrt = elapsed_time(&mytime);
		if (datum->rrt < 0)
			return 0;
		datum->rrt = rrt;
		if (datum->rrt > datum->timo * 1000) {
			close(datum->sock);
			return 0;
		}
	} while (recv_ping(&sa, datum));
	close(datum->sock);

	return 1;
}

int
pinghost(const char *hostname)
{
	struct ping_priv datum = ping_priv_default();
	return myping(hostname, 0, &datum);
}

int
pingthost(const char *hostname, int t)
{
	struct ping_priv datum = ping_priv_default();
	return myping(hostname, t, &datum);
}

int
tpinghost(const char *hostname)
{
	int ret;
	struct ping_priv datum = ping_priv_default();

	ret = myping(hostname, 0, &datum);
	if (ret > 0)
		ret = datum.rrt;
	return ret;
}

int
tpingthost(const char *hostname, int t)
{
	int ret;
	struct ping_priv datum = ping_priv_default();

	ret = myping(hostname, t, &datum);
	if (ret > 0)
		ret = datum.rrt;
	return ret;
}