ip header returned with raw packet, checksum must be 0 for calculating

checksum, use best measurement if within RANGE, check sequence numbers

SCCS-vsn: usr.sbin/timed/timed/measure.c 2.3

diff --git a/usr/src/usr.sbin/timed/timed/measure.c b/usr/src/usr.sbin/timed/timed/measure.c
index b6e9601..a85b31a 100644 (file)
--- a/usr/src/usr.sbin/timed/timed/measure.c
+++ b/usr/src/usr.sbin/timed/timed/measure.c
@@ -5,7 +5,7 @@
  */
 
 #ifndef lint
  */
 
 #ifndef lint

-static char sccsid[] = "@(#)measure.c  2.2 (Berkeley) %G%";
+static char sccsid[] = "@(#)measure.c  2.3 (Berkeley) %G%";

 #endif not lint
 
 #include "globals.h"
 #endif not lint
 
 #include "globals.h"


@@ -24,6 +24,7 @@ static char sccsid[] = "@(#)measure.c 2.2 (Berkeley) %G%";
 extern int id;
 int measure_delta;
 extern int sock_raw;
 extern int id;
 int measure_delta;
 extern int sock_raw;

+static n_short seqno = 0;

 
 /*
  * Measures the differences between machines' clocks using
 
 /*
  * Measures the differences between machines' clocks using


@@ -36,19 +37,20 @@ struct sockaddr_in *addr;
 {
        int length;
        int status;
 {
        int length;
        int status;

-       int msgcount, trials, ntransmitted;
+       int msgcount, trials;

        int cc, count;
        fd_set ready;
        long sendtime, recvtime, histime;
        long min1, min2, diff;
        register long delta1, delta2;
        struct timeval tv1, tout;
        int cc, count;
        fd_set ready;
        long sendtime, recvtime, histime;
        long min1, min2, diff;
        register long delta1, delta2;
        struct timeval tv1, tout;

-       u_char packet[PACKET_IN];
+       u_char packet[PACKET_IN], opacket[64];

        register struct icmp *icp = (struct icmp *) packet;
        register struct icmp *icp = (struct icmp *) packet;

-       
+       register struct icmp *oicp = (struct icmp *) opacket;
+       struct ip *ip = (struct ip *) packet;
+

        min1 = min2 = 0x7fffffff;
        min1 = min2 = 0x7fffffff;

-       ntransmitted = 1;
-       status = GOOD;
+       status = HOSTDOWN;

        measure_delta = HOSTDOWN;
 
 /* empties the icmp input queue */
        measure_delta = HOSTDOWN;
 
 /* empties the icmp input queue */


@@ -75,27 +77,27 @@ empty:
         */
 
        length = sizeof(struct sockaddr_in);
         */
 
        length = sizeof(struct sockaddr_in);

-       icp->icmp_type = ICMP_TSTAMP;
-       icp->icmp_code = 0;
-       icp->icmp_cksum = 0;
-       icp->icmp_id = id;
-       icp->icmp_rtime = 0;
-       icp->icmp_ttime = 0;
+       oicp->icmp_type = ICMP_TSTAMP;
+       oicp->icmp_code = 0;
+       oicp->icmp_cksum = 0;
+       oicp->icmp_id = id;
+       oicp->icmp_rtime = 0;
+       oicp->icmp_ttime = 0;

        FD_ZERO(&ready);
        msgcount = 0;
        for (trials = 0; msgcount < MSGS && trials < TRIALS; ++trials) {
        FD_ZERO(&ready);
        msgcount = 0;
        for (trials = 0; msgcount < MSGS && trials < TRIALS; ++trials) {

-               icp->icmp_seq = ntransmitted++;
-               trials++;
+               oicp->icmp_seq = ++seqno;
+               oicp->icmp_cksum = 0;

 
                tout.tv_sec = wait->tv_sec;
                tout.tv_usec = wait->tv_usec;
 
                (void)gettimeofday (&tv1, (struct timezone *)0);
 
                tout.tv_sec = wait->tv_sec;
                tout.tv_usec = wait->tv_usec;
 
                (void)gettimeofday (&tv1, (struct timezone *)0);

-               sendtime = icp->icmp_otime = (tv1.tv_sec % (24*60*60)) * 1000 
+               sendtime = oicp->icmp_otime = (tv1.tv_sec % (24*60*60)) * 1000 

                                                        + tv1.tv_usec / 1000;
                                                        + tv1.tv_usec / 1000;

-               icp->icmp_cksum = in_cksum((u_short *)icp, sizeof(*icp));
+               oicp->icmp_cksum = in_cksum((u_short *)oicp, sizeof(*oicp));

        
        

-               count = sendto(sock_raw, (char *)packet, sizeof(*icp), 0, 
+               count = sendto(sock_raw, (char *)opacket, sizeof(*oicp), 0, 

                                addr, sizeof(struct sockaddr_in));
                if (count < 0) {
                        status = UNREACHABLE;
                                addr, sizeof(struct sockaddr_in));
                if (count < 0) {
                        status = UNREACHABLE;


@@ -111,9 +113,10 @@ empty:
                        (void)gettimeofday(&tv1, (struct timezone *)0);
                        if (cc < 0)
                                return(-1);
                        (void)gettimeofday(&tv1, (struct timezone *)0);
                        if (cc < 0)
                                return(-1);

-                       if((icp->icmp_type != ICMP_TSTAMPREPLY) || 
-                           icp->icmp_id != id)
-                               continue;
+                       icp = (struct icmp *)(packet + (ip->ip_hl << 2));
+                       if((icp->icmp_type == ICMP_TSTAMPREPLY) &&
+                           icp->icmp_id == id && icp->icmp_seq == seqno)
+                               break;

                }
                if (count <= 0)
                        continue;               /* resend */
                }
                if (count <= 0)
                        continue;               /* resend */


@@ -137,6 +140,7 @@ empty:
                        status = NONSTDTIME;
                        break;
                }
                        status = NONSTDTIME;
                        break;
                }

+               status = GOOD;

                delta1 = histime - sendtime;
                /*
                 * Handles wrap-around to avoid that around 
                delta1 = histime - sendtime;
                /*
                 * Handles wrap-around to avoid that around 


@@ -157,8 +161,11 @@ empty:
                        min1 = delta1;
                if (delta2 < min2)
                        min2 = delta2;
                        min1 = delta1;
                if (delta2 < min2)
                        min2 = delta2;

-               if (diff < RANGE)
+               if (diff < RANGE) {
+                       min1 = delta1;
+                       min2 = delta2;

                        break;
                        break;

+               }

        }
 
        /*
        }
 
        /*