#ifndef lint
static char sccsid[] = "@(#)measure.c 8.2 (Berkeley) 3/26/95";
#endif
#ifdef sgi
#ident "$Revision: 1.1.1.1 $"
#endif
#include "globals.h"
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#define MSEC_DAY (SECDAY*1000)
#define PACKET_IN 1024
#define MSGS 5
#define TRIALS 10
extern int sock_raw;
int measure_delta;
static n_short seqno = 0;
int
measure(maxmsec, wmsec, hname, addr, print)
u_long maxmsec;
u_long wmsec;
char *hname;
struct sockaddr_in *addr;
int print;
{
int length;
int measure_status;
int rcvcount, trials;
int cc, count;
fd_set ready;
long sendtime, recvtime, histime1, histime2;
long idelta, odelta, total;
long min_idelta, min_odelta;
struct timeval tdone, tcur, ttrans, twait, tout;
u_char packet[PACKET_IN], opacket[64];
register struct icmp *icp = (struct icmp *) packet;
register struct icmp *oicp = (struct icmp *) opacket;
struct ip *ip = (struct ip *) packet;
min_idelta = min_odelta = 0x7fffffff;
measure_status = HOSTDOWN;
measure_delta = HOSTDOWN;
errno = 0;
if (sock_raw < 0) {
sock_raw = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
if (sock_raw < 0) {
syslog(LOG_ERR, "opening raw socket: %m");
goto quit;
}
}
FD_ZERO(&ready);
for (;;) {
tout.tv_sec = tout.tv_usec = 0;
FD_SET(sock_raw, &ready);
if (select(sock_raw+1, &ready, 0,0, &tout)) {
length = sizeof(struct sockaddr_in);
cc = recvfrom(sock_raw, (char *)packet, PACKET_IN, 0,
0,&length);
if (cc < 0)
goto quit;
continue;
}
break;
}
oicp->icmp_type = ICMP_TSTAMP;
oicp->icmp_code = 0;
oicp->icmp_id = getpid();
oicp->icmp_rtime = 0;
oicp->icmp_ttime = 0;
oicp->icmp_seq = seqno;
FD_ZERO(&ready);
#ifdef sgi
sginap(1);
#endif
(void)gettimeofday(&tdone, 0);
mstotvround(&tout, maxmsec);
timevaladd(&tdone, &tout);
mstotvround(&twait, wmsec);
rcvcount = 0;
trials = 0;
while (rcvcount < MSGS) {
(void)gettimeofday(&tcur, 0);
if (trials < TRIALS) {
trials++;
oicp->icmp_otime = htonl((tcur.tv_sec % SECDAY) * 1000
+ tcur.tv_usec / 1000);
oicp->icmp_cksum = 0;
oicp->icmp_cksum = in_cksum((u_short*)oicp,
sizeof(*oicp));
count = sendto(sock_raw, opacket, sizeof(*oicp), 0,
(struct sockaddr*)addr,
sizeof(struct sockaddr));
if (count < 0) {
if (measure_status == HOSTDOWN)
measure_status = UNREACHABLE;
goto quit;
}
++oicp->icmp_seq;
ttrans = tcur;
timevaladd(&ttrans, &twait);
} else {
ttrans = tdone;
}
while (rcvcount < trials) {
timevalsub(&tout, &ttrans, &tcur);
if (tout.tv_sec < 0)
tout.tv_sec = 0;
FD_SET(sock_raw, &ready);
count = select(sock_raw+1, &ready, (fd_set *)0,
(fd_set *)0, &tout);
(void)gettimeofday(&tcur, (struct timezone *)0);
if (count <= 0)
break;
length = sizeof(struct sockaddr_in);
cc = recvfrom(sock_raw, (char *)packet, PACKET_IN, 0,
0,&length);
if (cc < 0)
goto quit;
icp = (struct icmp *)(packet + (ip->ip_hl << 2));
if (cc < sizeof(*ip)
|| icp->icmp_type != ICMP_TSTAMPREPLY
|| icp->icmp_id != oicp->icmp_id
|| icp->icmp_seq < seqno
|| icp->icmp_seq >= oicp->icmp_seq)
continue;
sendtime = ntohl(icp->icmp_otime);
recvtime = ((tcur.tv_sec % SECDAY) * 1000 +
tcur.tv_usec / 1000);
total = recvtime-sendtime;
if (total < 0)
continue;
rcvcount++;
histime1 = ntohl(icp->icmp_rtime);
histime2 = ntohl(icp->icmp_ttime);
if ((histime1 & 0x80000000) != 0) {
measure_status = NONSTDTIME;
goto quit;
}
measure_status = GOOD;
idelta = recvtime-histime2;
odelta = histime1-sendtime;
if (idelta < -MSEC_DAY/2) idelta += MSEC_DAY;
else if (idelta > MSEC_DAY/2) idelta -= MSEC_DAY;
if (odelta < -MSEC_DAY/2) odelta += MSEC_DAY;
else if (odelta > MSEC_DAY/2) odelta -= MSEC_DAY;
if (total < MIN_ROUND) {
measure_delta = (odelta - idelta)/2;
goto quit;
}
if (idelta < min_idelta)
min_idelta = idelta;
if (odelta < min_odelta)
min_odelta = odelta;
measure_delta = (min_odelta - min_idelta)/2;
}
if (tcur.tv_sec > tdone.tv_sec
|| (tcur.tv_sec == tdone.tv_sec
&& tcur.tv_usec >= tdone.tv_usec))
break;
}
quit:
seqno += TRIALS;
if (measure_status == GOOD) {
if (trace) {
fprintf(fd,
"measured delta %4d, %d trials to %-15s %s\n",
measure_delta, trials,
inet_ntoa(addr->sin_addr), hname);
}
} else if (print) {
if (errno != 0)
fprintf(stderr, "measure %s: %s\n", hname,
strerror(errno));
} else {
if (errno != 0) {
syslog(LOG_ERR, "measure %s: %m", hname);
} else {
syslog(LOG_ERR, "measure: %s did not respond", hname);
}
if (trace) {
fprintf(fd,
"measure: %s failed after %d trials\n",
hname, trials);
(void)fflush(fd);
}
}
return(measure_status);
}
void
mstotvround(res, x)
struct timeval *res;
long x;
{
#ifndef sgi
if (x < 0)
x = -((-x + 3)/5);
else
x = (x+3)/5;
x *= 5;
#endif
res->tv_sec = x/1000;
res->tv_usec = (x-res->tv_sec*1000)*1000;
if (res->tv_usec < 0) {
res->tv_usec += 1000000;
res->tv_sec--;
}
}
void
timevaladd(tv1, tv2)
struct timeval *tv1, *tv2;
{
tv1->tv_sec += tv2->tv_sec;
tv1->tv_usec += tv2->tv_usec;
if (tv1->tv_usec >= 1000000) {
tv1->tv_sec++;
tv1->tv_usec -= 1000000;
}
if (tv1->tv_usec < 0) {
tv1->tv_sec--;
tv1->tv_usec += 1000000;
}
}
void
timevalsub(res, tv1, tv2)
struct timeval *res, *tv1, *tv2;
{
res->tv_sec = tv1->tv_sec - tv2->tv_sec;
res->tv_usec = tv1->tv_usec - tv2->tv_usec;
if (res->tv_usec >= 1000000) {
res->tv_sec++;
res->tv_usec -= 1000000;
}
if (res->tv_usec < 0) {
res->tv_sec--;
res->tv_usec += 1000000;
}
}