usr/src/contrib/tcpdump/tcpdump/print-ntp.c

/*
 * Copyright (c) 1988-1990 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that: (1) source code distributions
 * retain the above copyright notice and this paragraph in its entirety, (2)
 * distributions including binary code include the above copyright notice and
 * this paragraph in its entirety in the documentation or other materials
 * provided with the distribution, and (3) all advertising materials mentioning
 * features or use of this software display the following acknowledgement:
 * ``This product includes software developed by the University of California,
 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
 * the University nor the names of its contributors may be used to endorse
 * or promote products derived from this software without specific prior
 * written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Format and print ntp packets.
 *      By Jeffrey Mogul/DECWRL
 *      loosely based on print-bootp.c
 */

#ifndef lint
static char rcsid[] =
    "@(#) $Header: print-ntp.c,v 1.7 92/01/04 01:45:16 leres Exp $ (LBL)";
#endif

#include <stdio.h>

#include <sys/param.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <strings.h>
#include <ctype.h>

#include "interface.h"
#include "addrtoname.h"
#include "ntp.h"

/*
 * Print ntp requests
 */
void
ntp_print(bp, length)
        register struct ntpdata *bp;
        int length;
{
        u_char *ep;
        int mode, version, leapind;
        static char rclock[5];

#define TCHECK(var, l) if ((u_char *)&(var) > ep - l) goto trunc

        /* Note funny sized packets */
        if (length != sizeof(struct ntpdata))
                (void)printf(" [len=%d]", length);

        /* 'ep' points to the end of avaible data. */
        ep = (u_char *)snapend;

        TCHECK(bp->status, sizeof(bp->status));

        version = (bp->status & VERSIONMASK) >> 3;
        printf(" v%d", version);

        leapind = bp->status & LEAPMASK;
        switch (leapind) {

        case NO_WARNING:
                break;

        case PLUS_SEC:
                fputs(" +1s", stdout);
                break;

        case MINUS_SEC:
                fputs(" -1s", stdout);
                break;
        }

        mode = bp->status & MODEMASK;
        switch (mode) {

        case MODE_UNSPEC:       /* unspecified */
                fputs(" unspec", stdout);
                break;

        case MODE_SYM_ACT:      /* symmetric active */
                fputs(" sym_act", stdout);
                break;

        case MODE_SYM_PAS:      /* symmetric passive */
                fputs(" sym_pas", stdout);
                break;

        case MODE_CLIENT:       /* client */
                fputs(" client", stdout);
                break;

        case MODE_SERVER:       /* server */
                fputs(" server", stdout);
                break;

        case MODE_BROADCAST:    /* broadcast */
                fputs(" bcast", stdout);
                break;

        case MODE_RES1:         /* reserved */
                fputs(" res1", stdout);
                break;

        case MODE_RES2:         /* reserved */
                fputs(" res2", stdout);
                break;

        }

        TCHECK(bp->stratum, sizeof(bp->stratum));
        printf(" strat %d", bp->stratum);

        TCHECK(bp->ppoll, sizeof(bp->ppoll));
        printf(" poll %d", bp->ppoll);

        /* Can't TCHECK bp->precision bitfield so bp->distance + 0 instead */
        TCHECK(bp->distance, 0);
        printf(" prec %d", bp->precision);

        if (!vflag)
                return;

        TCHECK(bp->distance, sizeof(bp->distance));
        fputs(" dist ", stdout);
        p_sfix(&bp->distance);

        TCHECK(bp->dispersion, sizeof(bp->dispersion));
        fputs(" disp ", stdout);
        p_sfix(&bp->dispersion);

        TCHECK(bp->refid, sizeof(bp->refid));
        fputs(" ref ", stdout);
        /* Interpretation depends on stratum */
        switch (bp->stratum) {

        case UNSPECIFIED:
        case PRIM_REF:
                strncpy(rclock, (char *)&(bp->refid), 4);
                rclock[4] = '\0';
                fputs(rclock, stdout);
                break;

        case INFO_QUERY:
                printf("%s INFO_QUERY", ipaddr_string(&(bp->refid)));
                /* this doesn't have more content */
                return;

        case INFO_REPLY:
                printf("%s INFO_REPLY", ipaddr_string(&(bp->refid)));
                /* this is too complex to be worth printing */
                return;

        default:
                printf("%s", ipaddr_string(&(bp->refid)));
                break;
        }

        TCHECK(bp->reftime, sizeof(bp->reftime));
        putchar('@');
        p_ntp_time(&(bp->reftime));

        TCHECK(bp->org, sizeof(bp->org));
        fputs(" orig ", stdout);
        p_ntp_time(&(bp->org));

        TCHECK(bp->rec, sizeof(bp->rec));
        fputs(" rec ", stdout);
        p_ntp_delta(&(bp->org), &(bp->rec));

        TCHECK(bp->xmt, sizeof(bp->xmt));
        fputs(" xmt ", stdout);
        p_ntp_delta(&(bp->org), &(bp->xmt));

        return;

trunc:
        fputs(" [|ntp]", stdout);
#undef TCHECK
}

p_sfix(sfp)
        register struct s_fixedpt *sfp;
{
        register int i;
        register int f;
        register float ff;

        i = ntohs(sfp->int_part);
        f = ntohs(sfp->fraction);
        ff = f / 65536.0;       /* shift radix point by 16 bits */
        f = ff * 1000000.0;     /* Treat fraction as parts per million */
        printf("%d.%06d", i, f);
}

#define FMAXINT (4294967296.0)  /* floating point rep. of MAXINT */

p_ntp_time(lfp)
        register struct l_fixedpt *lfp;
{
        register long i;
        register unsigned long uf;
        register unsigned long f;
        register float ff;

        i = ntohl(lfp->int_part);
        uf = ntohl(lfp->fraction);
        ff = uf;
        if (ff < 0.0)           /* some compilers are buggy */
                ff += FMAXINT;
        ff = ff / FMAXINT;      /* shift radix point by 32 bits */
        f = ff * 1000000000.0;  /* treat fraction as parts per billion */
        printf("%lu.%09d", i, f);
}

/* Prints time difference between *lfp and *olfp */
p_ntp_delta(olfp, lfp)
        register struct l_fixedpt *olfp;
        register struct l_fixedpt *lfp;
{
        register long i;
        register unsigned long uf;
        register unsigned long ouf;
        register unsigned long f;
        register float ff;
        int signbit;

        i = ntohl(lfp->int_part) - ntohl(olfp->int_part);

        uf = ntohl(lfp->fraction);
        ouf = ntohl(olfp->fraction);

        if (i > 0) {            /* new is definitely greater than old */
                signbit = 0;
                f = uf - ouf;
                if (ouf > uf)   /* must borrow from high-order bits */
                        i -= 1;
        } else if (i < 0) {     /* new is definitely less than old */
                signbit = 1;
                f = ouf - uf;
                if (uf > ouf)   /* must carry into the high-order bits */
                        i += 1;
                i = -i;
        } else {                /* int_part is zero */
                if (uf > ouf) {
                        signbit = 0;
                        f = uf - ouf;
                } else {
                        signbit = 1;
                        f = ouf - uf;
                }
        }

        ff = f;
        if (ff < 0.0)           /* some compilers are buggy */
                ff += FMAXINT;
        ff = ff / FMAXINT;      /* shift radix point by 32 bits */
        f = ff * 1000000000.0;  /* treat fraction as parts per billion */
        if (signbit)
                putchar('-');
        else
                putchar('+');
        printf("%d.%09d", i, f);
}